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1
Izawa, Kensuke, and Sang-Ho Hyon. "Prototyping Force-Controlled 3-DOF Hydraulic Arms for Humanoid Robots." Journal of Robotics and Mechatronics 28, no. 1 (February 18, 2016): 95–103. http://dx.doi.org/10.20965/jrm.2016.p0095.
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[abstFig src='/00280001/11.jpg' width=""230"" text='Hydraulic dual arm robot prototype' ]This paper reports on a hydraulic dual arm robot developed as a rapid prototype for our hydraulic humanoid robot. The lightweight arms (4 kg each) have three joints driven by hydraulic linear servo actuators that can achieve higher torque and speed than human arms. A double four-bar linkage provides a wide range of motion (210°) to the shoulder joint. Each joint has torque controllability that is fully utilized for compliant whole-body motion control tasks. Based on singular perturbation analysis, we discuss how damping on the joints is actively modulated by hydraulic force feedback control, which is then utilized in our passivity-based task-space force control scheme. The effectiveness of the proposed system is experimentally evaluated through zero-force tracking gravity compensation with a 10 kg payload and object manipulation tasks.
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Vermillion, Billy C., Peter S. Lum, and Sang Wook Lee. "Proximal arm kinematics affect grip force-load force coordination." Journal of Neurophysiology 114, no. 4 (October 2015): 2265–77. http://dx.doi.org/10.1152/jn.00227.2015.
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During object manipulation, grip force is coordinated with load force, which is primarily determined by object kinematics. Proximal arm kinematics may affect grip force control, as proximal segment motion could affect control of distal hand muscles via biomechanical and/or neural pathways. The aim of this study was to investigate the impact of proximal kinematics on grip force modulation during object manipulation. Fifteen subjects performed three vertical lifting tasks that involved distinct proximal kinematics (elbow/shoulder), but resulted in similar end-point (hand) trajectories. While temporal coordination of grip and load forces remained similar across the tasks, proximal kinematics significantly affected the grip force-to-load force ratio ( P = 0.042), intrinsic finger muscle activation ( P = 0.045), and flexor-extensor ratio ( P < 0.001). Biomechanical coupling between extrinsic hand muscles and the elbow joint cannot fully explain the observed changes, as task-related changes in intrinsic hand muscle activation were greater than in extrinsic hand muscles. Rather, between-task variation in grip force (highest during task 3) appears to contrast to that in shoulder joint velocity/acceleration (lowest during task 3). These results suggest that complex neural coupling between the distal and proximal upper extremity musculature may affect grip force control during movements, also indicated by task-related changes in intermuscular coherence of muscle pairs, including intrinsic finger muscles. Furthermore, examination of the fingertip force showed that the human motor system may attempt to reduce variability in task-relevant motor output (grip force-to-load force ratio), while allowing larger fluctuations in output less relevant to task goal (shear force-to-grip force ratio).
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Hassan, Mahir, and Leila Notash. "Analysis of Active Joint Failure in Parallel Robot Manipulators." Journal of Mechanical Design 126, no. 6 (November 1, 2004): 959–68. http://dx.doi.org/10.1115/1.1798071.
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In this study, the effect of active joint failure on the mobility, velocity, and static force of parallel robot manipulators is investigated. Two catastrophic active joint failure types are considered: joint jam and actuator force loss. To investigate the effect of failure on mobility, the Gru¨bler’s mobility equation is modified to take into account the kinematic constraints imposed by various branches in the manipulator. In the case of joint jam, the manipulator loses the ability to move and apply force in a specific portion of its task space; while in the case of actuator force loss, the manipulator gains an unconstrained motion in a specific portion of the task space in which an externally applied force cannot be resisted by the actuator forces. The effect of joint jam and actuator force loss on the velocity and on the force capabilities of parallel manipulators is investigated by examining the change in the Jacobian matrix, its inverse, and transposes. It is shown that the reduced velocity and force capabilities after joint jam and loss of actuator force could be determined using the null space vectors of the transpose of the Jacobian matrix and its inverse. Computer simulation is conducted to demonstrate the application of the developed methodology in determining the post-failure trajectory of a 3-3 six-degree-of-freedom Stewart-Gough manipulator, when encountering active joint jam and actuator force loss.
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D’AGOSTINO, MARIA-ANTONIETTA, PHILIP G. CONAGHAN, ESPERANZA NAREDO, PHILIPPE AEGERTER, ANNAMARIA IAGNOCCO, JANE E. FREESTON, EMILIO FILIPPUCCI, et al. "The OMERACT Ultrasound Task Force — Advances and Priorities." Journal of Rheumatology 36, no. 8 (August 2009): 1829–32. http://dx.doi.org/10.3899/jrheum.090354.
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This article reports the most recent work of the OMERACT Ultrasound Task Force (post OMERACT 8) and highlights of future research priorities discussed at the OMERACT 9 meeting, Kananaskis, Canada, May 2008. Results of 3 studies were presented: (1) assessing intermachine reliability; (2) applying the scoring system developed in the hand to other joints most commonly affected in rheumatoid arthritis (RA); and (3) assessing interobserver reliability on a deep target joint (shoulder). Results demonstrated good intermachine reliability between multiple examiners, and good applicability of the scoring system for the hand on other joints (including shoulder). Study conclusions were discussed and a future research agenda was generated, notably the further development of a Global OMERACT Sonography Scoring (GLOSS) system in RA, emphasizing the importance of testing feasibility and added value over standard clinical variables. Future disease areas of importance to develop include a scoring system for enthesitis and osteoarthritis.
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Firmani, Flavio, and Ron P. Podhorodeski. "FORCE-UNCONSTRAINED POSES OF THE 3-PRR AND 4-PRR PLANAR PARALLEL MANIPULATORS." Transactions of the Canadian Society for Mechanical Engineering 29, no. 4 (December 2005): 617–28. http://dx.doi.org/10.1139/tcsme-2005-0040.
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Force-unconstrained (singular) poses of the 3-PRR planar parallel manipulator (PPM), where the underscore indicates the actuated joint, and the 4-PRR, a redundant PPM with an additional actuated branch, are presented. The solution of these problems is based upon concepts of reciprocal screw quantities and kinematic analysis. In general, non-redundant PPMs such as the 3-PRR are known to have two orders of infinity of force-unconstrained poses, i.e., a three-variable polynomial in terms of the task-space variables (position and orientation of the mobile platform). The inclusion of redundant branches eliminates one order of infinity of force-unconstrained configurations for every actuated branch beyond three. The geometric identification of force-unconstrained poses is carried out by assuming one variable for each order of infinity. In order to simplify the algebraic procedure of these problems, the assumed or “free” variables are considered to be joint displacements. For both manipulators, an effective elimination technique is adopted. For the 3-PRR, the roots of a 6th-order polynomial determine the force-unconstrained poses, i.e., surfaces in a three dimensional space defined by the task-space variables. For the 4-PRR, a 64th-order polynomial determines curves of force-unconstrained poses in the same dimensional space.
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Chou, P. H., Y. L. Chou, H. C. Wei, C. S. Ho, and S. S. Jiang. "Biomechanical Analysis of Wrist Loading During Lifting Tasks." Journal of Mechanics 17, no. 4 (December 2001): 179–87. http://dx.doi.org/10.1017/s172771910000191x.
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ABSTRACTThis study develops a kinematic/kinetic model to evaluate the effect of different handle angles on wrist loading during lifting task. An imaged-based motion analysis system is used to study the movement pattern, force and moment of the wrist joint among nine different handle angles. Six CCD cameras were used to record 3-D trajectories of limb-mounted markers based on the laboratory coordination system as defined by an 8-marker cube. Euler angles are used to describe the orientation of a distal segment reference frame relative to a proximal segment reference frame. Each segment of the upper extremities is regarded as a uniform rigid body with six degrees of freedom. The resultant loading of the wrist joints was determined using an inverse dynamic procedure.This study indicates that tool handles can be designed or selected to reduce manual loading and the potential for injury during tool use. The mean curve of joint force and moment provided consultations and understandings of the wrist loading during lifting task. In this study, handles that kept the wrist joints in a dorsiflexed and radial deviated position, showed significant reduction in stresses around the surrounding soft tissue.
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Hong, D. A., D. M. Corcos, and G. L. Gottlieb. "Task dependent patterns of muscle activation at the shoulder and elbow for unconstrained arm movements." Journal of Neurophysiology 71, no. 3 (March 1, 1994): 1261–65. http://dx.doi.org/10.1152/jn.1994.71.3.1261.
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1. Six subjects performed three series of pointing tasks with the unconstrained arm. Series one and two required subjects to move as fast as possible with different weights attached to the wrist. The first required flexion at both shoulder and elbow joints. The second required shoulder flexion and elbow extension. The third series required flexion at both joints and subjects were intentionally instructed to vary movement speed. These three pointing tasks were selected as the simplest progression from single to multiple degree of freedom movements in which different patterns of motoneuron excitation are required depending on whether movements are made against different loads or at different intended speeds. 2. Changes in load and changes in intended speed both produced systematic but different changes in the patterns of muscle activity and joint torque in both the elbow and shoulder muscles. These patterns are the same found during constrained, single-joint elbow flexion movements. The changes are expressed in the rates of rise, durations, and latencies of the electromyographic (EMG) bursts and in the rates of rise of torque that have specific dependencies based on the force requirements of the task. 3. A consistent, almost linear relationship is observed between muscle torque at the shoulder and at the elbow for all three tasks. Similar systematic changes were not seen in the kinematic description of joint angles.(ABSTRACT TRUNCATED AT 250 WORDS)
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Chernyak, Nataliya, and Volodymyr Kiyanytsya. "Actual problems of interaction between investigators and operational units during assignment and conduct of search." Naukovyy Visnyk Dnipropetrovs'kogo Derzhavnogo Universytetu Vnutrishnikh Sprav 1, no. 1 (March 29, 2021): 291–98. http://dx.doi.org/10.31733/2078-3566-2021-1-291-298.
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The article deals with study of problems related to the interaction of investigators with operational units during the appointment and conduct of the search. On the basis of the scientific analysis of normative-legal acts certain features of correctness of carrying out such investigative (search) action, as search with observance of all requirements specified in the Criminal procedure code of Ukraine and the laws of Ukraine have been found out. After having analyzed the regulations in accordance with this issue, it has been concluded that the interaction between investigative and operational units is carried out in the following organizational forms: 1) exchange of information; 2) joint discussion of opinions, proposals, conclusions on the materials of the proceedings and on issues of interaction; 3) joint planning; 4) joint participation in carrying out separate investigative (search) actions. It has been concluded that the effective procedural interaction of the investigator with the operational units during the search as part of the investigative task force is characterized by the following features: 1) the search has the same purpose; 2) all actions of the members of the investigative task force must be agreed upon during the development of a single plan; 3) each of the members of the investigative task force acts within its powers and retains its functional independence; 4) work as a member of the investigative task force gives the investigator the opportunity to use the data obtained promptly as soon as possible, and to operational officers – the information obtained during the search (in compliance with the principles of strict confidentiality)
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Enoka, R. M., G. A. Robinson, and A. R. Kossev. "Task and fatigue effects on low-threshold motor units in human hand muscle." Journal of Neurophysiology 62, no. 6 (December 1, 1989): 1344–59. http://dx.doi.org/10.1152/jn.1989.62.6.1344.
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1. The activity of single motor units was recorded in the first dorsal interosseus muscle of human subjects while they performed an isometric ramp-and-hold maneuver. Motor-unit activity was characterized before and after fatigue by the use of a branched bipolar electrode that was positioned subcutaneously over the test muscle. Activity was characterized in terms of the forces of recruitment and derecruitment and the discharge pattern. The purpose was to determine, before and after fatigue, whether motor-unit activity was affected by the direction in which the force was exerted. 2. Regardless of the task during prefatigue trials, interimpulse intervals were 1) more variable during increases or decreases in force than when force was held constant at the target value (4-6% above the recruitment force), and 2) more clustered around an arbitrary central value than would be expected with a normal (Gaussian) distribution. Both effects were seen during the flexion and abduction tasks. The behavior of low-threshold motor units in first dorsal interosseus is thus largely unaffected by the direction of the force exerted by the index finger. The absence of a task (i.e., a direction of force) effect suggests that the resultant force vector about the metacarpophalangeal joint of the index finger is not coded in terms of discrete populations of motor units, but, rather, it is based on the net muscle activity about the joint. 3. Motor-unit behavior during and after fatigue showed that the relatively homogeneous behavior seen before fatigue could be severely disrupted. The fatiguing protocol involved the continuous repetition, to the endurance limit, of a 15-s ramp-and-hold maneuver in which the abduction target force was 50% of maximum and was held for 10-s epochs (ramps up and down were approximately 2 s each). Motor-unit threshold was assessed by the forces of recruitment and derecruitment associated with each cycle of the fatigue test. Changes in recruitment force during the protocol were either minimal or, when present, not systematic. In contrast, the derecruitment force of all units exhibited a marked and progressive increase over the course of the test. 4. After the fatigue test, when the initial threshold tasks were repeated, the behavior of most motor units changed. These changes included the derecruitment of previously active motor units, the recruitment of additional motor units, and an increased discharge variability of units that remained recruited. The variation in recruitment order seemed to be much greater than that reported previously for nonfatiguing conditions.(ABSTRACT TRUNCATED AT 400 WORDS)
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Rai, Sanjay K., Sanjay Zodpey, Sanghamitra Ghosh, and A. Kadri. "Joint Statement on CoVID-19 Pandemic in India: Review of Current Strategy and the Way Forward." Indian Journal of Community Health 32, no. 2 (Supp) (April 20, 2020): 170–74. http://dx.doi.org/10.47203/ijch.2020.v32i02supp.001.
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A Joint Task Force of eminent public health experts of India was constituted by IPHA, and IAPSM to help the Government of India for containment of COVID-19 pandemic in the country.
The terms of reference of the Joint Task Force was to 1) To review and collate the scientific epidemiological literature pertaining to COVID-19 in India at national and state level; 2) To develop consensus amongst the experts regarding COVID-19 disease epidemiology and trends and develop action plan based on the consensus; 3) To widely disseminate the consensus statement and action plan with public health experts, other medical professional associations and other key stakeholders; 4) To share the consensus statement with the policy makers at highest level at centre and state.
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Simpson, Jeffrey D., Ethan M. Stewart, Alana J. Turner, David M. Macias, Harish Chander, and Adam C. Knight. "Lower Limb Joint Kinetics During a Side-Cutting Task in Participants With or Without Chronic Ankle Instability." Journal of Athletic Training 55, no. 2 (February 1, 2020): 169–75. http://dx.doi.org/10.4085/1062-6050-334-18.
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Context Individuals with chronic ankle instability (CAI) demonstrate altered lower limb movement dynamics during jump landings, which can contribute to recurrent injury. However, the literature examining lower limb movement dynamics during a side-cutting task in individuals with CAI is limited. Objective To assess lower limb joint kinetics and sagittal-plane joint stiffness during the stance phase of a side-cutting task in individuals with or without CAI. Design Cohort study. Setting Motion-capture laboratory. Patients or Other Participants Fifteen physically active, young adults with CAI (7 men, 8 women; age = 21.3 ± 1.6 years, height = 171.0 ± 11.2 cm, mass = 73.4 ± 15.2 kg) and 15 healthy matched controls (7 men, 8 women; age = 21.5 ± 1.5 years, height = 169.9 ± 10.6 cm, mass = 75.5 ± 13.0 kg). Intervention(s) Lower limb 3-dimensional kinematic and ground reaction force data were recorded while participants completed 3 successful trials of a side-cutting task. Net internal joint moments, in addition to sagittal-plane ankle-, knee-, and hip-joint stiffness, were computed from 3-dimensional kinematic and ground reaction force data during the stance phase of the side-cutting task and analyzed. Main Outcome Measure(s) Data from each participant's stance phase were normalized to 100% from initial foot contact (0%) to toe-off (100%) to compute means, standard deviations, and Cohen d effect sizes for all dependent variables. Results The CAI group exhibited a reduced ankle-eversion moment (39%–81% of stance phase) and knee-abduction moment (52%–75% of stance phase) and a greater ankle plantar-flexion moment (3%–16% of stance phase) than the control group (P range = .009–.049). Sagittal-plane hip-joint stiffness was greater in the CAI than in the control group (t28 = 1.978, P = .03). Conclusions Our findings suggest that altered ankle-joint kinetics and increased hip-joint stiffness were associated when individuals with CAI performed a side-cutting task. These lower limb kinetic changes may contribute to an increased risk of recurrent lateral ankle sprains in people with CAI. Clinicians and practitioners can use these findings to develop rehabilitation programs for improving maladaptive movement mechanics in individuals with CAI.
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Semmler, John G., Kylie J. Tucker, Trevor J. Allen, and Uwe Proske. "Eccentric exercise increases EMG amplitude and force fluctuations during submaximal contractions of elbow flexor muscles." Journal of Applied Physiology 103, no. 3 (September 2007): 979–89. http://dx.doi.org/10.1152/japplphysiol.01310.2006.
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The purpose of this study was to determine the effect of eccentric exercise on the ability to exert steady submaximal forces with muscles that cross the elbow joint. Eight subjects performed two tasks requiring isometric contraction of the right elbow flexors: a maximum voluntary contraction (MVC) and a constant-force task at four submaximal target forces (5, 20, 35, 50% MVC) while electromyography (EMG) was recorded from elbow flexor and extensor muscles. These tasks were performed before, after, and 24 h after a period of eccentric (fatigue and muscle damage) or concentric exercise (fatigue only). MVC force declined after eccentric exercise (45% decline) and remained depressed 24 h later (24%), whereas the reduced force after concentric exercise (22%) fully recovered the following day. EMG amplitude during the submaximal contractions increased in all elbow flexor muscles after eccentric exercise, with the greatest change in the biceps brachii at low forces (3–4 times larger at 5 and 20% MVC) and in the brachialis muscle at moderate forces (2 times larger at 35 and 50% MVC). Eccentric exercise resulted in a twofold increase in coactivation of the triceps brachii muscle during all submaximal contractions. Force fluctuations were larger after eccentric exercise, particularly at low forces (3–4 times larger at 5% MVC, 2 times larger at 50% MVC), with a twofold increase in physiological tremor at 8–12 Hz. These data indicate that eccentric exercise results in impaired motor control and altered neural drive to elbow flexor muscles, particularly at low forces, suggesting altered motor unit activation after eccentric exercise.
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Wolniakowski, Adam, Charalampos Valsamos, Kanstantsin Miatliuk, Vassilis Moulianitis, and Nikos Aspragathos. "Optimization of Dynamic Task Location within a Manipulator’s Workspace for the Utilization of the Minimum Required Joint Torques." Electronics 10, no. 3 (January 26, 2021): 288. http://dx.doi.org/10.3390/electronics10030288.
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The determination of the optimal position of a robotic task within a manipulator’s workspace is crucial for the manipulator to achieve high performance regarding selected aspects of its operation. In this paper, a method for determining the optimal task placement for a serial manipulator is presented, so that the required joint torques are minimized. The task considered comprises the exercise of a given force in a given direction along a 3D path followed by the end effector. Given that many such tasks are usually conducted by human workers and as such the utilized trajectories are quite complex to model, a Human Robot Interaction (HRI) approach was chosen to define the task, where the robot is taught the task trajectory by a human operator. Furthermore, the presented method considers the singular free paths of the manipulator’s end-effector motion in the configuration space. Simulation results are utilized to set up a physical execution of the task in the optimal derived position within a UR-3 manipulator’s workspace. For reference the task is also placed at an arbitrary “bad” location in order to validate the simulation results. Experimental results verify that the positioning of the task at the optimal location derived by the presented method allows for the task execution with minimum joint torques as opposed to the arbitrary position.
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Kim, Hyunsoo, S. Jun Son, Matthew K. Seeley, and J. Ty Hopkins. "Altered Movement Biomechanics in Chronic Ankle Instability, Coper, and Control Groups: Energy Absorption and Distribution Implications." Journal of Athletic Training 54, no. 6 (June 1, 2019): 708–17. http://dx.doi.org/10.4085/1062-6050-483-17.
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Context Patients with chronic ankle instability (CAI) exhibit deficits in neuromuscular control, resulting in altered movement strategies. However, no researchers have examined neuromuscular adaptations to dynamic movement strategies during multiplanar landing and cutting among patients with CAI, individuals who are ankle-sprain copers, and control participants. Objective To investigate lower extremity joint power, stiffness, and ground reaction force (GRF) during a jump-landing and cutting task among CAI, coper, and control groups. Design Cross-sectional study. Setting Laboratory. Patients or Other Participants A total of 22 patients with CAI (age = 22.7 ± 2.0 years, height = 174.6 ± 10.4 cm, mass = 73.4 ± 12.1 kg), 22 ankle-sprain copers (age = 22.1 ± 2.1 years, height = 173.8 ± 8.2 cm, mass = 72.6 ± 12.3 kg), and 22 healthy control participants (age = 22.5 ± 3.3 years, height = 172.4 ± 13.3 cm, mass = 72.6 ± 18.7 kg). Intervention(s) Participants performed 5 successful trials of a jump-landing and cutting task. Main Outcome Measure(s) Using motion-capture cameras and a force plate, we collected lower extremity ankle-, knee-, and hip-joint power and stiffness and GRFs during the jump-landing and cutting task. Functional analyses of variance were used to evaluate between-groups differences in these dependent variables throughout the contact phase of the task. Results Compared with the coper and control groups, the CAI group displayed (1) up to 7% of body weight more posterior and 52% of body weight more vertical GRF during initial landing followed by decreased GRF during the remaining stance and 22% of body weight less medial GRF across most of stance; (2) 8.8 W/kg less eccentric and 3.2 W/kg less concentric ankle power, 6.4 W/kg more eccentric knee and 4.8 W/kg more eccentric hip power during initial landing, and 5.0 W/kg less eccentric knee and 3.9 W/kg less eccentric hip power; and (3) less ankle- and knee-joint stiffness during the landing phase. Concentric power patterns were similar to eccentric power patterns. Conclusions The CAI group demonstrated altered neuromechanics, redistributing energy absorption from the distal (ankle) to the proximal (knee and hip) joints, which coincided with decreased ankle and knee stiffness during landing. Our data suggested that although the coper and control groups showed similar landing and cutting strategies, the CAI group used altered strategies to modulate impact forces during the task.
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Minshull, Claire, and Lewis James. "The effects of hypohydration and fatigue on neuromuscular activation performance." Applied Physiology, Nutrition, and Metabolism 38, no. 1 (January 2013): 21–26. http://dx.doi.org/10.1139/apnm-2012-0189.
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This study investigated the effects of hypohydration by fluid restriction on voluntary and evoked indices of neuromuscular performance at a functional joint angle. Measures of static volitional peak force (2–3–s maximal muscle actions) and evoked peak twitch force, electromechanical delay, and rate of force development were obtained from the knee extensors (30° knee flexion) of 10 males (age, 24 (4) years; height, 1.76 (0.10) m; body mass, 78.7 (9.13) kg (mean (SD))) prior to and immediately following 24 h of (i) euhydration (EU) and (ii) hypohydration (HYP). Neuromuscular performance was also assessed in response to a fatiguing task (3 × 30-s maximal static knee extensions) following each condition. Repeated-measures ANOVAs showed that HYP was associated with a significant 2.1% loss in body mass (p < 0.001) and a 7.8% reduction in volitional peak force (p < 0.05). Following fatigue, data indicated statistically similar levels of impairment to volitional peak force (11.6%, p < 0.01) and rate of force development (21.0%, p < 0.01) between conditions (EU; HYP). No changes to any other indices of performance were observed. The substantive hypohydration-induced deficits to muscle strength at this functional joint angle might convey a decreased performance capability and should be considered by the hypohydrated athlete. Whilst hypohydration did not affect fatigue-related performance of the knee extensors, the additive changes associated with lower baseline levels of strength performance (7.8%) and fatigue (11.6%) coupled with slower rate of muscle force production (from 0–100 ms) following fatigue may present significant challenges to the maintenance of dynamic knee joint stability, particularly at this vulnerable joint position.
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Oshima, Toru, Tomohiko Fujikawa, and Minayori Kumamoto. "Control of Elasticity and Trajectory of Robot Arm with Redundant Actuators." Journal of Robotics and Mechatronics 14, no. 3 (June 20, 2002): 253–61. http://dx.doi.org/10.20965/jrm.2002.p0253.
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In mechanical joints applied to robot arms, one actuator is generally required to drive one joint. For the drive of joints on the musculoskeletal system of animal limbs, in which musculi skeleti are used as actuators, there is a pair of bi-articular muscles for driving two joints simultaneously in addition to a pair of monoarticular muscles. By our study with a simple arm model having a 2 degrees of freedom for two joints, the relationship between the compliances of antagonistic muscless at a joint (the muscle coordinate system) and the elastic ellipse at the end of arm (the task coordinate system) has been clarified in connection with the adjustment of the trajectory at the end of arm, which belongs to the task coordinate system, when the bi-articular muscles are made available and when they are made un-available for comparison. The effect of the bi-articular muscles has thus been proved. Then the fact that the trajectory of the arm can be adjusted by means of both an elastic ellipse and the force at the end of the arm has also been clarified. To verify the above, a 2 degrees of freedom robot arm has been adopted. This arm is equipped with two joints having (3-pairs, 6-muscles) pneumatic rubber artificial muscles used as actuators.
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Gottlieb, G. L., M. L. Latash, D. M. Corcos, T. J. Liubinskas, and G. C. Agarwal. "Organizing principles for single joint movements: V. Agonist-antagonist interactions." Journal of Neurophysiology 67, no. 6 (June 1, 1992): 1417–27. http://dx.doi.org/10.1152/jn.1992.67.6.1417.
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1. Normal human subjects made discrete elbow flexions in the horizontal plane under different task conditions of initial or final position, inertial loading, or instruction about speed. We measured joint angle, acceleration, and electromyographic signals (EMGs) from two agonist and two antagonist muscles. 2. For many of the experimental tasks, the latency of the antagonist EMG burst was strongly correlated with parameters of the first agonist EMG burst defined by a single equation, expressed in terms of the agonist's hypothetical excitation pulse. Latency is proportional to the ratio of pulse duration to pulse intensity, making it proportional to movement distance and inertial load and inversely proportional to planned movement speed. However, these rules are not sufficient to define the timing of every possible single joint movement. 3. For movements described by the speed-insensitive strategy, the quantity of both antagonist and agonist muscle activity can be uniformly associated with selected kinetic measures that incorporate muscle force-velocity relations. 4. For movements collectively described by the speed-sensitive strategy, (i.e., that have direct or indirect constraints on speed), no single rule can describe all the combinations of agonist-antagonist coordination that are used to perform these diverse tasks. 5. Estimates of joint viscosity were made by calculating the amount of velocity-dependent torque used to terminate movements on target. These estimates are similar to those that have previously been made of limb viscosity during postural maintenance. They imply that a significant component of muscle activity must be used to overcome these forces. 6. These and previous results are all consistent with a dual-strategy hypothesis for those single-joint movements that are sufficiently fast to require pulse-like muscle activation patterns. The major features of such patterns (pulse intensities, durations, and latencies) are determined by central commands programmed in advance of movement initiation. The selection between speed-insensitive or speed-sensitive rules of motoneuron pool excitation is implicitly specified by the nature of speed constraints of the movement task.
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McLean, S. G., A. Su, and A. J. van den Bogert. "Development and Validation of a 3-D Model to Predict Knee Joint Loading During Dynamic Movement." Journal of Biomechanical Engineering 125, no. 6 (December 1, 2003): 864–74. http://dx.doi.org/10.1115/1.1634282.
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The purpose of this study was to develop a subject-specific 3-D model of the lower extremity to predict neuromuscular control effects on 3-D knee joint loading during movements that can potentially cause injury to the anterior cruciate ligament (ACL) in the knee. The simulation consisted of a forward dynamic 3-D musculoskeletal model of the lower extremity, scaled to represent a specific subject. Inputs of the model were the initial position and velocity of the skeletal elements, and the muscle stimulation patterns. Outputs of the model were movement and ground reaction forces, as well as resultant 3-D forces and moments acting across the knee joint. An optimization method was established to find muscle stimulation patterns that best reproduced the subject’s movement and ground reaction forces during a sidestepping task. The optimized model produced movements and forces that were generally within one standard deviation of the measured subject data. Resultant knee joint loading variables extracted from the optimized model were comparable to those reported in the literature. The ability of the model to successfully predict the subject’s response to altered initial conditions was quantified and found acceptable for use of the model to investigate the effect of altered neuromuscular control on knee joint loading during sidestepping. Monte Carlo simulations (N=100,000) using randomly perturbed initial kinematic conditions, based on the subject’s variability, resulted in peak anterior force, valgus torque and internal torque values of 378 N, 94 Nm and 71 Nm, respectively, large enough to cause ACL rupture. We conclude that the procedures described in this paper were successful in creating valid simulations of normal movement, and in simulating injuries that are caused by perturbed neuromuscular control.
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Lyle, Mark A., and T. Richard Nichols. "Patterns of intermuscular inhibitory force feedback across cat hindlimbs suggest a flexible system for regulating whole limb mechanics." Journal of Neurophysiology 119, no. 2 (February 1, 2018): 668–78. http://dx.doi.org/10.1152/jn.00617.2017.
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Prior work has suggested that Golgi tendon organ feedback, via its distributed network linking muscles spanning all joints, could be used by the nervous system to help regulate whole limb mechanics if appropriately organized. We tested this hypothesis by characterizing the patterns of intermuscular force-dependent feedback between the primary extensor muscles spanning the knee, ankle, and toes in decerebrate cat hindlimbs. Intermuscular force feedback was evaluated by stretching tendons of selected muscles in isolation and in pairwise combinations and then measuring the resulting force-dependent intermuscular interactions. The relative inhibitory feedback between extensor muscles was examined, as well as symmetry of the interactions across limbs. Differences in the directional biases of inhibitory feedback were observed across cats, with three patterns identified as points on a spectrum: pattern 1, directional bias of inhibitory feedback onto the ankle extensors and toe flexors; pattern 2, convergence of inhibitory feedback onto ankle extensors and mostly balanced inhibitory feedback between vastus muscle group and flexor hallucis longus, and pattern 3, directional bias of inhibitory feedback onto ankle and knee extensors. The patterns of inhibitory feedback, while different across cats, were symmetric across limbs of individual cats. The variable but structured distribution of force feedback across cat hindlimbs provides preliminary evidence that inhibitory force feedback could be a regulated neural control variable. We propose the directional biases of inhibitory feedback observed experimentally could provide important task-dependent benefits, such as directionally appropriate joint compliance, joint coupling, and compensation for nonuniform inertia. NEW & NOTEWORTHY Feedback from Golgi tendon organs project widely among extensor motor nuclei in the spinal cord. The distributed nature of force feedback suggests these pathways contribute to the global regulation of limb mechanics. Analysis of this network in individual animals indicates that the strengths of these pathways can be reorganized appropriately for a variety of motor tasks, including level walking, slope walking, and landing.
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Eslami, Nima, Alexander Harms, Johann Deringer, Andreas Fricke, and Stefan Böhm. "Dissimilar Friction Stir Butt Welding of Aluminum and Copper with Cross-Section Adjustment for Current-Carrying Components." Metals 8, no. 9 (August 24, 2018): 661. http://dx.doi.org/10.3390/met8090661.
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Manufacturing dissimilar joints of aluminum and copper is a challenging task. However, friction stir welding (FSW) was found to be a suitable technique to produce aluminum–copper joints. Due to different electrical conductivities between aluminum and copper, an adjustment of the cross-section is required to realize electrical conductors free of resistive losses. Taking this into account, this paper presents initial results on the mechanical and electrical properties of friction stir butt welded aluminum and copper blanks having thicknesses of 4.7 mm and 3 mm, respectively. Three different approaches were investigated with the aim to produce sound welds with properties similar to those of the used base materials. Friction stir welding has been conducted at a welding speed of 450 mm/min. Subsequently, the welded specimens were subjected to metallographic analysis, tensile testing, and measurements of the electrical conductivity. The ultimate tensile force of the best joints was about 10 kN, which corresponds to joint efficiencies of approximately 72% of the aluminum base material. The analysis of electrical joint properties led to very promising results, so that the potential of FSW of Al–Cu butt joints with sheets having different thicknesses could be confirmed by the investigations carried out.
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Grindstaff, Terry L., Jay Hertel, James R. Beazell, Eric M. Magrum, D. Casey Kerrigan, Xitao Fan, and Christopher D. Ingersoll. "Lumbopelvic Joint Manipulation and Quadriceps Activation of People With Patellofemoral Pain Syndrome." Journal of Athletic Training 47, no. 1 (January 1, 2012): 24–31. http://dx.doi.org/10.4085/1062-6050-47.1.24.
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Context: Quadriceps weakness and inhibition are impairments associated with patellofemoral pain syndrome (PFPS). Lumbopelvic joint manipulation has been shown to improve quadriceps force output and inhibition, but the duration of the effect is unknown. Objective: To determine whether quadriceps strength and activation are increased and maintained for 1 hour after high-grade or low-grade joint mobilization or manipulation applied at the lumbopelvic region in people with PFPS. Design: Randomized controlled clinical trial. Setting: University laboratory. Patients or Other Participants: Forty-eight people with PFPS (age = 24.6±8.9 years, height = 174.3 ± 11.2 cm, mass = 78.4 ± 16.8 kg) participated. Intervention(s): Participants were randomized to 1 of 3 groups: lumbopelvic joint manipulation (grade V), side-lying lumbar midrange flexion and extension passive range of motion (grade II) for 1 minute, or prone extension on the elbows for 3 minutes. Main Outcome Measure(s): Quadriceps force and activation were measured using the burst superimposition technique during a seated isometric knee extension task. A 2-way repeated-measures analysis of variance was performed to compare changes in quadriceps force and activation among groups over time (before intervention and at 0, 20, 40, and 60 minutes after intervention). Results: We found no differences in quadriceps force output (F5,33,101,18 = 0.65, P = .67) or central activation ratio (F4.84,92.03 = 0.38, P= .86) values among groups after intervention. When groups were pooled, we found differences across time for quadriceps force (F2.66,101.18 = 5.03, P = .004) and activation (F2.42,92.03 = 3.85, P = .02). Quadriceps force was not different at 0 minutes after intervention (t40 = 1.68, P = .10), but it decreased at 20 (t40 = 2.16, P = .04), 40 (t40 = 2.87, P = .01) and 60 (t40 = 3.04, P = .004) minutes after intervention. All groups demonstrated decreased quadriceps activation at 0 minutes after intervention (t40 = 4.17, P <.001), but subsequent measures were not different from preintervention levels (t40 range, 1.53–1.83, P >.09). Conclusions: Interventions directed at the lumbopelvic region did not have immediate effects on quadriceps force output or activation. Muscle fatigue might have contributed to decreased force output and activation over 1 hour of testing.
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Stoustrup, Peter, Marinka Twilt, Lynn Spiegel, Kasper Dahl Kristensen, Bernd Koos, Thomas Klit Pedersen, Annelise Küseler, et al. "Clinical Orofacial Examination in Juvenile Idiopathic Arthritis: International Consensus-based Recommendations for Monitoring Patients in Clinical Practice and Research Studies." Journal of Rheumatology 44, no. 3 (January 15, 2017): 326–33. http://dx.doi.org/10.3899/jrheum.160796.
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Objective.To develop international consensus-based recommendations for the orofacial examination of patients with juvenile idiopathic arthritis (JIA), for use in clinical practice and research.Methods.Using a sequential phased approach, a multidisciplinary task force developed and evaluated a set of recommendations for the orofacial examination of patients with JIA. Phase 1: A Delphi survey was conducted among 40 expert physicians and dentists with the aim of identifying and ranking the importance of items for inclusion. Phase 2: The task force developed consensus about the domains and items to be included in the recommendations. Phase 3: A systematic literature review was performed to assess the evidence supporting the consensus-based recommendations. Phase 4: An independent group of orofacial and JIA experts were invited to assess the content validity of the task force’s recommendations.Results.Five recommendations were developed to assess the following 5 domains: medical history, orofacial symptoms, muscle and temporomandibular joint function, orofacial function, and dentofacial growth. After application of data search criteria, 56 articles were included in the systematic review. The level of evidence for the 5 recommendations was derived primarily from descriptive studies, such as cross-sectional and case-control studies.Conclusion.Five recommendations are proposed for the orofacial examination of patients with JIA to improve the clinical practice and aid standardized data collection for future studies. The task force has formulated a future research program based on the proposed recommendations.
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Farquhar, Sara J., Darcy S. Reisman, and Lynn Snyder-Mackler. "Persistence of Altered Movement Patterns During a Sit-to-Stand Task 1 Year Following Unilateral Total Knee Arthroplasty." Physical Therapy 88, no. 5 (May 1, 2008): 567–79. http://dx.doi.org/10.2522/ptj.20070045.
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Background and Purpose Following total knee arthroplasty (TKA), quadriceps femoris muscle strength (force-generating capacity) and functional test scores improve but continue to be lower than those in people without injury. Analysis of the sit-to-stand (STS) task demonstrated side-to-side differences in subjects with TKA, as well as differences between subjects with TKA and control subjects. It was hypothesized that, when using a self-selected starting position, subjects 1 year following TKA would show improvements in strength and movement patterns but would continue to show asymmetries of angles and moments at the hips and knees. Subjects and Methods Twenty-four subjects (12 subjects with unilateral TKA and 12 control subjects) were recruited; those with TKA were tested 3 months and 1 year following surgery. Motion analysis of an STS task was synchronized with 2 force platforms and electromyography. Outcome measures included joint angles and moments, electromyography, vertical ground reaction forces, muscle strength, and functional performance tests. Results Subjects with TKA showed improvements in symmetry of motion, strength, and functional performance from 3 months to 1 year following TKA. Compared with control subjects, subjects with TKA relied on increased hip flexion and a larger hip extensor moment to perform the STS task. Discussion and Conclusion The increased hip extensor moment demonstrated that subjects adopted a strategy to avoid the use of the quadriceps femoris muscle, yet this strategy persisted as quadriceps femoris muscle strength improved. This pattern may be a learned movement pattern that may not resolve without retraining.
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Lempke, Landon B., Jeonghoon Oh, Rachel S. Johnson, Julianne D. Schmidt, and Robert C. Lynall. "Single- Versus Dual-Task Functional Movement Paradigms: A Biomechanical Analysis." Journal of Sport Rehabilitation 30, no. 5 (July 1, 2021): 774–85. http://dx.doi.org/10.1123/jsr.2020-0310.
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Context: Laboratory-based movement assessments are commonly performed without cognitive stimuli (ie, single-task) despite the simultaneous cognitive processing and movement (ie, dual task) demands required during sport. Cognitive loading may critically alter human movement and be an important consideration for truly assessing functional movement and understanding injury risk in the laboratory, but limited investigations exist. Objective: To comprehensively examine and compare kinematics and kinetics between single- and dual-task functional movement among healthy participants while controlling for sex. Design: Cross-sectional study. Setting: Laboratory. Patients (or Other Participants): Forty-one healthy, physically active participants (49% female; 22.5 ± 2.1 y; 172.5 ± 11.9 cm; 71.0 ± 13.7 kg) enrolled in and completed the study. Intervention(s): All participants completed the functional movement protocol under single- and dual-task (subtracting by 6s or 7s) conditions in a randomized order. Participants jumped forward from a 30-cm tall box and performed (1) maximum vertical jump landings and (2) dominant and (3) nondominant leg, single-leg 45° cuts after landing. Main Outcome Measures: The authors used mixed-model analysis of variances (α = .05) to compare peak hip, knee, and ankle joint angles (degrees) and moments (N·m/BW) in the sagittal and frontal planes, and peak vertical ground reaction force (N/BW) and vertical impulse (Ns/BW) between cognitive conditions and sex. Results: Dual-task resulted in greater peak vertical ground reaction force compared with single-task during jump landing (mean difference = 0.06 N/BW; 95% confidence interval [CI], 0.01 to 0.12; P = .025) but less force during dominant leg cutting (mean difference = −0.08 N/BW; 95% CI, −0.14 to −0.02; P = .015). Less hip-flexion torque occurred during dual task than single task (mean difference = −0.09 N/BW; 95% CI, −0.17 to −0.02). No other outcomes were different between single and dual task (P ≥ .053). Conclusions: Slight, but potentially important, kinematic and kinetic differences were observed between single- and dual-task that may have implications for functional movement assessments and injury risk research. More research examining how various cognitive and movement tasks interact to alter functional movement among pathological populations is warranted before clinical implementation.
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Tillman, Mark D., Chris J. Hass, John W. Chow, and Denis Brunt. "Lower Extremity Coupling Parameters during Locomotion and Landings." Journal of Applied Biomechanics 21, no. 4 (November 2005): 359–70. http://dx.doi.org/10.1123/jab.21.4.359.
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During ballistic locomotion and landing activities, the lower extremity joints must function synchronously to dissipate the impact. The coupling of subtalar motion to tibial and knee rotation has been hypothesized to depend on the dynamic requirements of the task. This study was undertaken to look for differences in the coupling of 3-D foot and knee motions during walking, jogging, and landing from a jump. Twenty recreationally active young women with normal foot alignment (as assessed by a licensed physical therapist) were videotaped with high-speed cameras (250 Hz) during walking, jogging, hopping, and jumping trials. Coupling coefficients were compared among the four activities. The ratio of eversion to tibial rotation increased from the locomotion to the landing trials, indicating that with the increased loading demands of the activity, the requirements of foot motion increased. However, this increased motion was not proportionately translated into rotation of the tibia through the subtalar joint. Furthermore, the ratio of knee flexion to knee internal rotation increased significantly from the walking to landing trials. Together these findings suggest that femoral rotation may compensate for the increase in tibial rotation as the force-dissipating demands of the task increase. The relative unbalance among the magnitude of foot, tibial, and knee rotations observed with increasing task demands may have direct implications on clinical treatments aimed at reducing knee motion via controlling motion at the foot during landing tasks.
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De Luca, C. J., and B. Mambrito. "Voluntary control of motor units in human antagonist muscles: coactivation and reciprocal activation." Journal of Neurophysiology 58, no. 3 (September 1, 1987): 525–42. http://dx.doi.org/10.1152/jn.1987.58.3.525.
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1. Myoelectric (ME) activity of several motor units was detected simultaneously from the human flexor pollicis longus and extensor pollicis longus muscles, the only two muscles that control the interphalangeal joint of the thumb. The ME signals were detected while the subjects produced isometric force outputs to track three different paradigms: triangular trajectories, random-force trajectories requiring both flexion and extension contractions, and net zero force resulting from stiffening the joint by voluntarily coactivating both muscles. 2. The ME signals were decomposed into their constituent motor-unit action potential trains. The firing rate behavior of the concurrently active motor units was studied using cross-correlation techniques. 3. During isometric contractions, the firing rates of motor units within a muscle were greatly cross-correlated with essentially zero time shift with respect to each other. This observation confirms our previous report of this behavior, which has been called common drive. Common drive was also found among the motor units of the agonist and antagonist muscles during voluntary coactivation to stiffen the interphalangeal joint. This observation suggests two interesting points: 1) that the common drive mechanism has a component of central origin, and 2) that the central nervous system may control the motoneuron pools of an agonist-antagonist muscle pair as if they were one pool when both are performing the same task. 4. During force reversals, the firing rates of motor units reverse in an orderly manner: earlier recruited motor units decrease their firing rate before later recruited motor units. This orderly reversal of firing rates is consistent with the concept of orderly recruitment and derecruitment. 5. A control scheme is suggested to explain the behavior of the motor units in both muscles during force reversal. It consists of centrally mediated reciprocally organized flexion and extension commands along with a common coactivation command to both muscles. This control scheme allows for coactivation and reciprocal activation of an agonist-antagonist set. 6. The agonist-antagonist pair was observed to generate a net force in two control modalities: proportional activation and reciprocal activation. In proportional activation, the agonist-antagonist set is coactivated during either of two states: when uncertainty exists in the required task or when a compensatory force contraction is perceived to be required.(ABSTRACT TRUNCATED AT 400 WORDS)
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Seeley, Matthew K., Seong Jun Son, Hyunsoo Kim, and J. Ty Hopkins. "Biomechanics Differ for Individuals With Similar Self-Reported Characteristics of Patellofemoral Pain During a High-Demand Multiplanar Movement Task." Journal of Sport Rehabilitation 30, no. 6 (August 1, 2021): 860–69. http://dx.doi.org/10.1123/jsr.2020-0220.
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Context: Patellofemoral pain (PFP) is often categorized by researchers and clinicians using subjective self-reported PFP characteristics; however, this practice might mask important differences in movement biomechanics between PFP patients. Objective: To determine whether biomechanical differences exist during a high-demand multiplanar movement task for PFP patients with similar self-reported PFP characteristics but different quadriceps activation levels. Design: Cross-sectional design. Setting: Biomechanics laboratory. Participants: A total of 15 quadriceps deficient and 15 quadriceps functional (QF) PFP patients with similar self-reported PFP characteristics. Intervention: In total, 5 trials of a high-demand multiplanar land, cut, and jump movement task were performed. Main Outcome Measures: Biomechanics were compared at each percentile of the ground contact phase of the movement task (α = .05) between the quadriceps deficient and QF groups. Biomechanical variables included (1) whole-body center of mass, trunk, hip, knee, and ankle kinematics; (2) hip, knee, and ankle kinetics; and (3) ground reaction forces. Results: The QF patients exhibited increased ground reaction force, joint torque, and movement, relative to the quadriceps deficient patients. The QF patients exhibited: (1) up to 90, 60, and 35 N more vertical, posterior, and medial ground reaction force at various times of the ground contact phase; (2) up to 4° more knee flexion during ground contact and up to 4° more plantarflexion and hip extension during the latter parts of ground contact; and (3) up to 26, 21, and 48 N·m more plantarflexion, knee extension, and hip extension torque, respectively, at various times of ground contact. Conclusions: PFP patients with similar self-reported PFP characteristics exhibit different movement biomechanics, and these differences depend upon quadriceps activation levels. These differences are important because movement biomechanics affect injury risk and athletic performance. In addition, these biomechanical differences indicate that different therapeutic interventions may be needed for PFP patients with similar self-reported PFP characteristics.
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DOUGADOS, MAXIME, GILLIAN HAWKER, STEFAN LOHMANDER, AILEEN M. DAVIS, PAUL DIEPPE, JEAN-FRANCIS MAILLEFERT, and LAURE GOSSEC. "OARSI/OMERACT Criteria of Being Considered a Candidate for Total Joint Replacement in Knee/Hip Osteoarthritis as an Endpoint in Clinical Trials Evaluating Potential Disease Modifying Osteoarthritic Drugs." Journal of Rheumatology 36, no. 9 (September 2009): 2097–99. http://dx.doi.org/10.3899/jrheum.090365.
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Objective.A disease-modifying osteoarthritic drug (DMOAD) should interfere with the cartilage breakdown observed and improve symptoms or prevent deterioration of the patient’s clinical condition. We propose a composite index including structural and symptomatic variables of osteoarthritis (OA) as criteria for being considered a candidate for total joint replacement as an endpoint in clinical trials evaluating potential DMOAD.Methods.An OARSI/OMERACT task force conducted this study in 3 steps: (1) The 3 main domains — pain, function, structure — were revisited; (2) For each of the domains a “non-acceptable state” and a “relevant” progression for their structure were defined; and (3) a set of criteria was proposed combining the information from these 3 domains.Results.A questionnaire was elaborated for the domains “pain” and “function.” Systematic research of the literature and evaluation of different databases concluded that the domain “structure” should be evaluated by radiological joint space width in millimeters. An unacceptable radiographic progression was defined as a change in the joint space width over the measurement error. An international, cross-sectional study is proposing a definition of a “nonacceptable symptom state.”Conclusion.The objective of the ongoing OARSI/OMERACT initiative is to propose criteria for being considered a candidate for total joint replacement to be used as an endpoint in clinical trials evaluating potential DMOAD. The preliminary steps of this initiative have been completed.
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Hewett, Timothy E., Gregory D. Myer, Kevin R. Ford, Robert S. Heidt, Angelo J. Colosimo, Scott G. McLean, Antonie J. van den Bogert, Mark V. Paterno, and Paul Succop. "Biomechanical Measures of Neuromuscular Control and Valgus Loading of the Knee Predict Anterior Cruciate Ligament Injury Risk in Female Athletes: A Prospective Study." American Journal of Sports Medicine 33, no. 4 (April 2005): 492–501. http://dx.doi.org/10.1177/0363546504269591.
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Background Female athletes participating in high-risk sports suffer anterior cruciate ligament injury at a 4- to 6-fold greater rate than do male athletes. Hypothesis Prescreened female athletes with subsequent anterior cruciate ligament injury will demonstrate decreased neuromuscular control and increased valgus joint loading, predicting anterior cruciate ligament injury risk. Study Design Cohort study; Level of evidence, 2. Methods There were 205 female athletes in the high-risk sports of soccer, basketball, and volleyball prospectively measured for neuromuscular control using 3-dimensional kinematics (joint angles) and joint loads using kinetics (joint moments) during a jump-landing task. Analysis of variance as well as linear and logistic regression were used to isolate predictors of risk in athletes who subsequently ruptured the anterior cruciate ligament. Results Nine athletes had a confirmed anterior cruciate ligament rupture; these 9 had significantly different knee posture and loading compared to the 196 who did not have anterior cruciate ligament rupture. Knee abduction angle (P <. 05) at landing was 8° greater in anterior cruciate ligament-injured than in uninjured athletes. Anterior cruciate ligament-injured athletes had a 2.5 times greater knee abduction moment (P <. 001) and 20% higher ground reaction force (P <. 05), whereas stance time was 16% shorter; hence, increased motion, force, and moments occurred more quickly. Knee abduction moment predicted anterior cruciate ligament injury status with 73% specificity and 78% sensitivity; dynamic valgus measures showed a predictive r2 of 0.88. Conclusion Knee motion and knee loading during a landing task are predictors of anterior cruciate ligament injury risk in female athletes. Clinical Relevance Female athletes with increased dynamic valgus and high abduction loads are at increased risk of anterior cruciate ligament injury. The methods developed may be used to monitor neuromuscular control of the knee joint and may help develop simpler measures of neuromuscular control that can be used to direct female athletes to more effective, targeted interventions.
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Lee, Jusung, Prabhat Pathak, Siddhartha Bikram Panday, and Jeheon Moon. "Effect of Foot-Planting Strategy on Anterior Cruciate Ligament Loading in Women During a Direction Diversion Maneuver: A Musculoskeletal Modeling Approach." Orthopaedic Journal of Sports Medicine 8, no. 11 (November 1, 2020): 232596712096318. http://dx.doi.org/10.1177/2325967120963180.
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Background: Although there is a higher prevalence of noncontact anterior cruciate ligament (ACL) injuries during a direction diversion maneuver (DDM), no previous studies have reported how foot-planting strategies affect ACL loading. Purpose: To investigate the effect of foot-planting strategies on ACL loading in women during a DDM task using a musculoskeletal modeling approach. Study Design: Descriptive laboratory study. Methods: A total of 13 female participants performed a DDM task, which involved running at 4.5 ± 0.2 m/s and turning left at 35° to 55° under a foot-planting strategy in 3 directions: neutral, toe-in, and toe-out. Kinematic and kinetic data were measured with the use of a 3-dimensional motion capture system and force platform to calculate variables such as joint angle, shear force, and moment. Anterior ACL and posterior ACL forces were extracted using musculoskeletal modeling. Results: The peak anterior ACL force was significantly larger for the toe-out condition (31.29 ± 4.02 N/body weight [BW]) compared with the toe-in condition (25.43 ± 5.68 N/BW) ( P = .047), with no significant difference in the neutral condition. The toe-out condition had a higher knee valgus angle (2.98° ± 4.20°; P = .041), knee shear force (10.20 ± 1.69 N/BW; P = .009), and knee internal rotation moment (–0.18 ± 0.16 N·m/BW×height; P = .012) than the toe-in and neutral conditions. Conclusion: Through musculoskeletal modeling, we were able to conclude that the toe-out condition during the DDM might result in a higher risk of ACL injuries. Athletes and sports practitioners should avoid the toe-out foot-planting strategy when participating in a sporting activity. Clinical Relevance: Based on these findings, medical professionals and athletic coaches can gain knowledge on how foot-planting strategy affects ACL loading. Understanding the actual cause of an ACL injury can be useful for designing preventive training programs or strategies to decrease the risk of such injuries.
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Stoustrup, Peter, Cory M. Resnick, Thomas Klit Pedersen, Shelly Abramowicz, Ambra Michelotti, Annelise Küseler, Carlalberta Verna, et al. "Standardizing Terminology and Assessment for Orofacial Conditions in Juvenile Idiopathic Arthritis: International, Multidisciplinary Consensus-based Recommendations." Journal of Rheumatology 46, no. 5 (January 15, 2019): 518–22. http://dx.doi.org/10.3899/jrheum.180785.
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Objective.To propose multidisciplinary, consensus-based, standardization of operational terminology and method of assessment for temporomandibular joint (TMJ) involvement in juvenile idiopathic arthritis (JIA).Methods.Using a sequential expert group–defined terminology and methods-of-assessment approach by (1) establishment of task force, (2) item generation, (3) working group consensus, (4) external expert content validity testing, and (5) multidisciplinary group of experts final Delphi survey consensus.Results.Seven standardized operational terms were defined: TMJ arthritis, TMJ involvement, TMJ arthritis management, dentofacial deformity, TMJ deformity, TMJ symptoms, and TMJ dysfunction.Conclusion.Definition of 7 operational standardized terms provides an optimal platform for communication across healthcare providers involved in JIA-TMJ arthritis management.
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Genova, Françoise, Raymond P. Norris, Olga B. Dluzhnevskaya, Michael S. Bessel, H. Jenker, Oleg Yu Malkov, Fionn Murtagh, et al. "COMMISSION 5: DOCUMENTATION AND ASTRONOMICAL DATA." Proceedings of the International Astronomical Union 3, T26B (December 2007): 212–16. http://dx.doi.org/10.1017/s1743921308024162.
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Commission 5 has been very active during the IAU XXVI General Assembly in Prague: the Commission, its Working Groups and its Task Force held business meetings. In addition, Commission 5 sponsored two Special Sessions: Special Session 3 on The Virtual Observatory in Action: New Science, New Technology, and Next Generation Facilities which was held for three days 17–22 August, and Special Session 6 on Astronomical Data Management, which was held on 22 August. Commission 5 also participated in the organisation of Joint Discussion 16 on Nomenclature, Precession and New Models in Fundamental Astronomy, which was held 22-23 August. The General Assembly and Commission 5 web sites provides links to detailed information about all these meetings.
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Szyszczak, Erika. "Social Policy." International and Comparative Law Quarterly 52, no. 4 (October 2003): 1013–21. http://dx.doi.org/10.1093/iclq/52.4.1013.
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The Barcelona Summit of March 2002 provided the catalyst for further coordination and synchronisation between the social and economic dimensions of the Lisbon Strategy framework. The definition of the ‘European Social Model’ as ‘good economic performance, a high level of social protection and education and social dialogue’ has become a working definition underpinning the direction of social policy in official publications.1 The Barcelona Presidency also led to the adoption of a streamlined set of Employment Guidelines, Recommendations to the Member States and Broad Economic Policy Guidelines on the same day, heralded as an ‘instrument for economic governance’ by the Commission.2 The reform of the European Employment Strategy (EES) concentrates upon the problems and weaknesses of the EES identified in the evaluation of the first 5 years of the Strategy.3 The Commission identified four central issues for reform, focusing upon the need to set clear objectives (which include priorities and targets), the need to simplify the policy guidelines, the need to improve governance and ensure greater consistency and complementarity with other EU processes. A new development on the eve of the Spring Council (the Brussels Summit) on 20–21 March 2003 was a ‘Social Summit’ attended by a troika of the Heads of State/Government of the past, current and future Presidencies, the Commission and the Social Partners. One outcome of this Summit was the creation of a new eight-member task force, chaired by Wim Kok.4 The aim of the European Employment Task Force is to investigate practical steps to prompt the Member States to implement the new revised EES endorsed at the Spring Summit. The Task Force will report to the Commission in time to draft the Joint Employment Report for the annual Spring Summits.
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Stoustrup, Peter, Troels Herlin, Lynn Spiegel, Hanna Rahimi, Bernd Koos, Thomas Klit Pedersen, and Marinka Twilt. "Standardizing the Clinical Orofacial Examination in Juvenile Idiopathic Arthritis: An Interdisciplinary, Consensus-based, Short Screening Protocol." Journal of Rheumatology 47, no. 9 (December 1, 2019): 1397–404. http://dx.doi.org/10.3899/jrheum.190661.
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Objective.To develop a consensus-based, standardized, short (< 3 min) clinical examination protocol to assess the multidimensional, orofacial manifestations of juvenile idiopathic arthritis (JIA).Methods.The study was conducted by a multidisciplinary task force from the Temporomandibular Joint Juvenile Arthritis Working Group (TMJaw). The study used an acknowledged sequential approach involving (1) a global multidisciplinary online questionnaire study, (2) a systematic literature review and consensus meetings to identify items for inclusion, (3) pilot testing of included items, (4) test of reliability in 22 subjects with JIA by 4 examiners, (5) test of construct validity in a case-control study involving 167 subjects, and (6) establishment of final recommendations.Results.Six items were recommended for the final examination protocol: (1) clinician-assessed pain location, (2) temporomandibular (TMJ) joint pain on palpation (open and closed mouth), (3) mandibular deviation at maximal mouth opening (≥ 3 mm), (4) maximal unassisted mouth opening capacity, (5) frontal facial symmetry, and (6) facial profile. All recommended items showed acceptable reliability and construct validity. The average mean examination time was 2 min and 42 s (SD ± 38.5 s).Conclusion.A consensus-based, short clinical examination protocol was developed. The protocol takes less than 3 min to complete and provides information about orofacial symptoms, TMJ dysfunction, and dentofacial deformity. The standardized examination protocol is applicable to routine clinical care, as well as future research studies.
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Xie, Fugui, Xin-Jun Liu, Chao Wu, and Pan Zhang. "A novel spray painting robotic device for the coating process in automotive industry." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 229, no. 11 (October 7, 2014): 2081–93. http://dx.doi.org/10.1177/0954406214553018.
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This paper proposes a novel concept for the spray painting robotic device, which is to be used in the coating process of the automotive industry. In order to realize compact design and simultaneously get better performance in terms of running speed and dynamic response, parallel kinematic mechanisms (PKMs) are introduced in this concept. In conjunction with the gantry beam, four standalone spray painting units are assigned and two kinds of PKMs (i.e. 3-RPS PKM and 5 R symmetrical PKM, R: revolute joint; P: prismatic joint; S: spherical joint) are used as the execution mechanisms of the four spray painting units. Based on this concept design, the kinematic optimization of the device is carried out by taking the motion/force transmission performance into consideration and the geometric parameters are derived. Sequentially, a prototype is developed and its performance in the coating process is investigated by a series of spray painting experiments on a Jetta car body and a SUV car body. The finished surfaces have good quality in terms of luster, uniformity, and thickness. Thus, this newly developed spray painting robotic device provides a better choice or solution for the coating task in automotive industry, and has good application prospect in this field.
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Li, Lin, Yanxia Li, Chang-hong Wu, and Hao Fu. "Upper Limb Proprioceptive Acuity Assessment Based on Three-Dimensional Position Measurement Systems." Motor Control 24, no. 4 (October 1, 2020): 605–23. http://dx.doi.org/10.1123/mc.2020-0009.
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The aim of the current work was to verify three-dimensional directional effects on the reproduction error precision of the human upper limb position. Thirty male subjects without history of upper limb pathology were recruited from Renmin University of China. A three-dimensional position reproduction task in six directions (up, down, left, right, far, and near) was performed by each subject. The results suggested that the proprioceptive sense of upper limb position depends on the direction, with smaller absolute errors in Directions 4 (right) and 5 (far) than in Directions 1 (up), 2 (down), 3 (left), and 6 (near). Proprioception near the end of the elbow joint range of motion may be more reliable and sensitive. Subjects reproduced fewer ranges in the horizontal plane (Directions 3, 5, and 6) and they overshot the target position along the z-axis (vertical direction) except for Direction 6. Overestimations of position in the z-axis may be caused by overestimations of force.
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Savelberg, H. H. C. M., and K. Meijer. "Contribution of mono- and biarticular muscles to extending knee joint moments in runners and cyclists." Journal of Applied Physiology 94, no. 6 (June 1, 2003): 2241–48. http://dx.doi.org/10.1152/japplphysiol.01001.2002.
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Motor actions are governed by coordinated activation of mono- and biarticular muscles. This study considered differences in mono- and biarticular knee extensors between runners and cyclists in the context of adaptations to task-specific movement requirements. Two hypotheses were tested: 1) the length-at-use hypothesis, which is that muscle adapts to have it operate around optimal length; and 2) the contraction-mode hypothesis, which is that eccentrically active muscles prefer to operate on the ascending limb of the length-force curve. Ten runners and ten cyclists performed maximal, isometric knee extensions on a dynamometer at five knee and four hip joint angles. This approach allowed the separation of the contribution of mono- and biarticular extensors. Three major differences occurred: 1) compared with runners, monoarticular extensors of cyclists reach optimal length at larger muscle length; 2) in runners, optimal length of the biarticular extensor is shifted to larger lengths; and 3) the moment generated by monoarticular extensor was larger in cyclists. Mono- and biarticular extensors respond to different adaptation triggers in runners and cyclists. Monoarticular muscles seem to adapt to the length-at-use, whereas biarticular muscles were found to be sensitive to the contraction-mode hypothesis.
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Ueno, Ryo, Alessandro Navacchia, Nathan D. Schilaty, Gregory D. Myer, Timothy E. Hewett, and Nathaniel A. Bates. "Anterior Cruciate Ligament Loading Increases With Pivot-Shift Mechanism During Asymmetrical Drop Vertical Jump in Female Athletes." Orthopaedic Journal of Sports Medicine 9, no. 3 (March 1, 2021): 232596712198909. http://dx.doi.org/10.1177/2325967121989095.
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Background: Frontal plane trunk lean with a side-to-side difference in lower extremity kinematics during landing increases unilateral knee abduction moment and consequently anterior cruciate ligament (ACL) injury risk. However, the biomechanical features of landing with higher ACL loading are still unknown. Validated musculoskeletal modeling offers the potential to quantify ACL strain and force during a landing task. Purpose: To investigate ACL loading during a landing and assess the association between ACL loading and biomechanical factors of individual landing strategies. Study Design: Descriptive laboratory study. Methods: Thirteen young female athletes performed drop vertical jump trials, and their movements were recorded with 3-dimensional motion capture. Electromyography-informed optimization was performed to estimate lower limb muscle forces with an OpenSim musculoskeletal model. A whole-body musculoskeletal finite element model was developed. The joint motion and muscle forces obtained from the OpenSim simulations were applied to the musculoskeletal finite element model to estimate ACL loading during participants’ simulated landings with physiologic knee mechanics. Kinematic, muscle force, and ground-reaction force waveforms associated with high ACL strain trials were reconstructed via principal component analysis and logistic regression analysis, which were used to predict trials with high ACL strain. Results: The median (interquartile range) values of peak ACL strain and force during the drop vertical jump were 3.3% (–1.9% to 5.1%) and 195.1 N (53.9 to 336.9 N), respectively. Four principal components significantly predicted high ACL strain trials, with 100% sensitivity, 78% specificity, and an area of 0.91 under the receiver operating characteristic curve ( P < .001). High ACL strain trials were associated with (1) knee motions that included larger knee abduction, internal tibial rotation, and anterior tibial translation and (2) motion that included greater vertical and lateral ground-reaction forces, lower gluteus medius force, larger lateral pelvic tilt, and increased hip adduction. Conclusion: ACL loads were higher with a pivot-shift mechanism during a simulated landing with asymmetry in the frontal plane. Specifically, knee abduction can create compression on the posterior slope of the lateral tibial plateau, which induces anterior tibial translation and internal tibial rotation. Clinical Relevance: Athletes are encouraged to perform interventional and preventive training to improve symmetry during landing.
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Falco, Frank J. E. "An Update of Evaluation of Therapeutic Thoracic Facet Joint Interventions." Pain Physician 4;15, no. 4;8 (August 14, 2012): E463—E481. http://dx.doi.org/10.36076/ppj.2012/15/e463.
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Background: Chronic mid back and upper back pain caused by thoracic facet joints has been reported in 34% to 48% of patients based on responses to controlled diagnostic blocks. Systematic reviews have established moderate evidence for controlled comparative local anesthetic blocks of thoracic facet joints in the diagnosis of mid back and upper back pain, moderate evidence for therapeutic thoracic medial branch blocks, and limited evidence for radiofrequency neurotomy of thoracic medial branches. Study Design: Systematic review of therapeutic thoracic facet joint interventions. Objective: To determine the clinical utility of therapeutic thoracic facet joint interventions in the therapeutic management of chronic upper back and mid back pain. Methods: The available literature for the utility of facet joint interventions in the therapeutic management of thoracic facet joint pain was reviewed. The quality assessment and clinical relevance criteria utilized were the Cochrane Musculoskeletal Review Group criteria as utilized for interventional techniques for randomized trials and the criteria developed by the Newcastle-Ottawa Scale criteria for observational studies. The level of evidence was classified as good, fair, and limited (or poor) based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF). Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 to March 2012, and manual searches of the bibliographies of known primary and review articles. Outcome Measures: The primary outcome measure was pain relief (short-term relief = up to 6 months and long-term > 6 months). Secondary outcome measures were improvement in functional status, psychological status, return to work, and reduction in opioid intake. Results: For this systematic review, 13 studies were identified. Of these, 7 studies were excluded, and a total of 4 studies (after removal of duplicate publication) met inclusion criteria for methodological quality assessment with one randomized trial and 3 non-randomized studies. The evidence is fair for therapeutic thoracic facet joint nerve blocks, limited for thoracic radiofrequency neurotomy, and not available for thoracic intraarticular injections. Limitations: The limitation of this systematic review includes a paucity of literature. The only positive studies were of medial branch blocks performed by the same group of authors. Conclusion: The evidence for therapeutic facet joint interventions is fair for medial branch blocks, whereas it is not available for intraarticular injections, and limited for radiofrequency neurotomy due to lack of literature. Key words: Chronic thoracic pain, mid back or upper back pain, thoracic facet or zygapophysial joint pain, facet joint nerve blocks, medial branch blocks, therapeutic thoracic medial branch blocks, thoracic radiofrequency neurotomy, thoracic intraarticular facet joint injections
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Datta, Sukdeb. "Systematic Assessment of Diagnostic Accuracy and Therapeutic Utility of Lumbar Facet Joint Interventions." Pain Physician 2;12, no. 2;3 (March 14, 2009): 437–60. http://dx.doi.org/10.36076/ppj.2009/12/437.
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Background: Lumbar facet joints are a well recognized source of low back pain and referred pain in the lower extremity in patients with chronic low back pain. Conventional clinical features and other non-invasive diagnostic modalities are unreliable in diagnosing lumbar zygapophysial joint pain. Controlled diagnostic studies have shown the prevalence of lumbar facet joint pain in 27% to 40% of the patients with chronic low back pain without disc displacement or radiculitis, with a false-positive rate of 27% to 47% with a single diagnostic block. Study Design: A systematic review of diagnostic and therapeutic lumbar facet joint interventions. Objective: To determine the clinical utility of diagnostic and therapeutic lumbar facet joint interventions in managing chronic low back pain of facet joint origin. Methods: Review of the literature for clinical studies on efficacy and utility of facet joint interventions in diagnosing and managing facet joint pain was performed according to the Agency for Healthcare Research and Quality (AHRQ) criteria for diagnostic studies and observational studies and the Cochrane Musculoskeletal Review Group criteria as utilized for interventional techniques for randomized trials. Data sources included relevant literature of the English language identified through searches of Medline and EMBASE from 1966 to December 2008 and manual searches of bibliographies of known primary and review articles. Analysis results were performed for diagnostic and therapeutic interventions separately. Level of Evidence: The level of evidence was defined as Level I, II, or III with 3 subcategories in Level II based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF) for therapeutic interventions. Outcome Measures: For diagnostic interventions, studies must have been performed utilizing controlled local anesthetic blocks. Pain relief was categorized as at least 80% pain relief from baseline pain and ability to perform previously painful movements. For therapeutic interventions, the primary outcome measure was pain relief with secondary outcome measures of improvement in functional status, psychological status, return to work, and reduction in opioid intake. For therapeutic interventions, short-term pain relief was defined as relief lasting 6 months or less and long-term relief as longer than 6 months. Results: Based on USPSTF criteria, evidence showed Level I or II-1 for diagnostic facet joint nerve blocks. Based on the review of included therapeutic studies, Level II-1 to II-2 evidence was indicated for lumbar facet joint nerve blocks with indicated level of evidence of Level II-2 to II-3 for lumbar radiofrequency neurotomy. Limitations: The shortcoming of this systematic review of lumbar facet joint interventions is the paucity of published literature. Conclusion: The evidence for diagnosis of lumbar facet joint pain with controlled local anesthetic blocks is Level I or II-1. The indicated level of evidence for therapeutic lumbar facet joint interventions is Level II1 or II-2 for lumbar facet joint nerve blocks, Level II-2 or II-3 evidence for radiofrequency neurotomy, and Level III (limited) evidence for intraarticular injections. Key words: Chronic low back pain, lumbar facet or zygapophysial joint pain, facet joint nerve blocks, medial branch blocks, controlled comparative local anesthetic blocks, lumbar radiofrequency neurotomy, lumbar intraarticular facet joint injections
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Rupert, Matthew P. "Evaluation of Sacroiliac Joint Interventions: A Systematic Appraisal of the Literature." Pain Physician 2;12, no. 2;3 (March 14, 2009): 399–418. http://dx.doi.org/10.36076/ppj.2009/12/399.
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Background: The sacroiliac joint has been implicated as a source of low back and lower extremity pain. There are no definite historical, physical, or radiological features that can definitively establish a diagnosis of sacroiliac joint pain. Based on the present knowledge, an accurate diagnosis is made only by controlled sacroiliac joint diagnostic blocks. The sacroiliac joint has been shown to be a source of pain in 10% to 27% of suspected patients with chronic low back pain utilizing controlled comparative local anesthetic blocks. Study Design: A systematic review of diagnostic and therapeutic sacroiliac joint interventions. Objective: To evaluate the accuracy of diagnostic sacroiliac joint interventions and the utility of therapeutic sacroiliac joint interventions. Methods: The literature search was carried out by searching the databases of PubMed, EMBASE, and Cochrane reviews. Methodologic quality assessment of included studies was performed using the Agency for Healthcare Research and Quality (AHRQ) methodologic quality criteria for diagnostic accuracy and observational studies, whereas randomized trials were evaluated utilizing the Cochrane review criteria. Only studies with scores of 50 or higher were included for assessment. Level of evidence was based on the U.S. Preventive Services Task Force (USPSTF) criteria. Outcome Measures: For diagnostic interventions, the outcome criteria included at least 50% pain relief coupled with a patient’s ability to perform previously painful maneuvers with sustained relief using placebo-controlled or comparative local anesthetic blocks. For therapeutic purposes, outcomes included significant pain relief and improvement in function and other parameters. Short-term relief for therapeutic interventions was defined as 6 months or less, whereas long-term effectiveness was defined as greater than 6 months. Results: The indicated level of evidence is II-2 for the diagnosis of sacroiliac joint pain utilizing comparative, controlled local anesthetic blocks. The prevalence of sacroiliac joint pain is estimated to range between 10% and 38% using a double block paradigm in the study population. The false-positive rate of single, uncontrolled, sacroiliac joint injections is 20% to 54%. The evidence for provocative testing to diagnose sacroiliac joint pain is Level II-3 or limited. For radiofrequency neurotomy the indicated evidence is limited (Level II-3) for short- and longterm relief. Limitations: The limitations of this systematic review include the paucity of literature evaluating the role of both diagnostic and therapeutic interventions and widespread methodological flaws. Conclusions: The indicated evidence for the validity of diagnostic sacroiliac joint injections is Level II-2. The evidence for the accuracy of provocative maneuvers in the diagnosing of sacroiliac joint pain is limited (Level II-3). The evidence for radiofrequency neurotomy is also limited (Level II-3). Key words: Chronic low back pain, sacroiliac joint pain, sacroiliitis, sacroiliac joint injection, sacroiliac joint dysfunction, thermal radiofrequency, pulsed radiofrequency
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Panjaitan, Troydimas. "Anatomy and Biomechanic of the Shoulder." Orthopaedic Journal of Sports Medicine 7, no. 11_suppl6 (November 1, 2019): 2325967119S0046. http://dx.doi.org/10.1177/2325967119s00466.
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The shoulder is one of the most complex joints of the human body. Consequently, they are susceptible to injury and degeneration. Mechanical shoulder pathology typically results when overuse, extremes of motion, or excessive forces overwhelm intrinsic material properties of the shoulder complex resulting in tears of the rotator cuff, capsule, and labrum. The fundamental central component of the shoulder complex is the glenohumeral joint. It has a ball-and-socket configuration with a surface area ratio of the humeral head to glenoid fossa of about 3:1 with an appearance similar to a golf ball on a tee. Overall, there is minimal bony covering and limited contact areas that allow extensive translational and rotational ability in all three planes. The glenohumeral joint has 2 groups of stabilizers, which are static (passive) and dynamic (active) restrains. Static stabilizers include the concavity of the glenoid fossa, glenoid fossa retroversion and superior angulation, glenoid labrum, the joint capsule, and glenohumeral ligaments, and a vacuum effect from negative intra-articular pressure. Dynamic stabilization is merely the coordinated contraction of the rotator cuff muscles that create forces that compress the articular surfaces of the humeral head into the concave surface of the glenoid fossa. During upper extremity movement, the effects of static stabilizers are minimized and dynamic or active stabilizers become the dominant forces responsible for glenohumeral stability The simple act of arm elevation is a complex task that occurs via the combination of glenohumeral and scapulothoracic motion, together known as scapulohumeral rhythm. In the first 1200, glenohumeral arm abduction, the supraspinatus and deltoid work together and create a force couple that promotes stability, while raising the arm (deltoid contraction). In addition, the humerus must undergo 450 external rotation to not only clear the greater tuberosity posteriorly but also loosen the inferior glenohumeral ligament (IGHL) to allow maximum elevation. There are several anatomical updates regarding the rotator cuff and capsular footprint. The footprint of the supraspinatus on the greater tuberosity is much smaller than previously believed, and this area of the greater tuberosity is actually occupied by a substantial amount of the infraspinatus. The superior-most insertion of the subscapularis tendon extends a thin tendinous slip, which attaches to the fovea capitis of the humerus. The teres minor muscle inserts to the lowest impression of the greater tuberosity of the humerus and additionally inserts to the posterior side of the surgical neck of the humerus.
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Kroon, Féline P. B., Philip G. Conaghan, Violaine Foltz, Frédérique Gandjbakhch, Charles Peterfy, Iris Eshed, Harry K. Genant, Mikkel Østergaard, Margreet Kloppenburg, and Ida K. Haugen. "Development and Reliability of the OMERACT Thumb Base Osteoarthritis Magnetic Resonance Imaging Scoring System." Journal of Rheumatology 44, no. 11 (March 1, 2017): 1694–98. http://dx.doi.org/10.3899/jrheum.161099.
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Objective.To develop the Outcome Measures in Rheumatology (OMERACT) thumb base osteoarthritis (OA) magnetic resonance imaging (MRI) scoring system (TOMS) for the assessment of inflammatory and structural abnormalities in this hand OA subset, and test its cross-sectional reliability.Methods.Included features and their scaling were agreed upon by members of the OMERACT MRI Task Force using the Hand OA MRI scoring system as a template. A reliability exercise was performed in which 3 readers participated, using a preliminary atlas with examples to facilitate reading. Each reader independently scored a set of 20 MRI (coronal and axial T1- and T2-weighted fat-suppressed images, of which 5 included T1-weighted fat-suppressed post-Gadolinium images). Intra- and inter-reader reliability were assessed using ICC, percentage exact agreement (PEA), and percentage close agreement (PCA).Results.The TOMS assessed the first carpometacarpal (CMC-1) and scaphotrapeziotrapezoid (STT) joints for synovitis, subchondral bone defects (including erosions, cysts, and bone attrition), osteophytes, cartilage, and bone marrow lesions on a 0–3 scale (normal to severe). Subluxation was evaluated only in the CMC-1 joint (absent/present). Reliability of scoring for both joints was comparable. Interreader ICC were good for all features (0.77–0.99 and 0.74–0.96 for CMC-1 and STT joints, respectively). Intrareader reliability analyses gave similar results. PCA was ≥ 65% for all features. PEA was low to moderate, with better performance for subchondral bone defects, subluxation, and bone marrow lesions.Conclusion.A thumb base OA MRI scoring system has been developed. The OMERACT TOMS demonstrated good intrareader and interreader reliability. Longitudinal studies are warranted to investigate reliability of change scores and responsiveness.
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Kolb, H. Robert, Huan Kuang, and Linda S. Behar-Horenstein. "Clinical research coordinators’ instructional preferences for competency content delivery." Journal of Clinical and Translational Science 2, no. 4 (August 2018): 217–22. http://dx.doi.org/10.1017/cts.2018.320.
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IntroductionA lack of standardized clinical research coordinator (CRC) training programs requires determining appropriate approaches for content delivery. The purpose of this study was to assess CRCs preferred training delivery methods related to the 8 designated Joint Task Force Clinical Trial Competency domains.MethodsRepeated measures analysis of variance and split-plot analysis of variance were adopted to compare the group means among 5 training delivery methods by 8 competency content domains and to examine whether demographic variables caused different preference patterns on the training delivery methods.ResultsParticipants reported a preference for online video; mentoring/coaching was the least preferred. Significant training delivery method preferences were reported for 3 content domains: participant safety considerations, medicines development and regulation, and clinical trials operations.DiscussionObserved statistical differences in the training delivery methods by the content domains provides guidance for program development. Ensuring that standardized educational training is aligned with the needs of adult learners may help ensure that CRCs are appropriately prepared for the workforce.
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Nguyen, Charles, Jennifer Mbuthia, and Craig P. Dobson. "Reduction in Medical Evacuations from Iraq and Syria Following Introduction of an Asynchronous Telehealth System." Military Medicine 185, no. 9-10 (June 27, 2020): e1693-e1699. http://dx.doi.org/10.1093/milmed/usaa091.
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Abstract Introduction While deployed, military medical personnel manage routine medical issues that fall under the category of Disease Non-Battle Injury (DNBI). The 86th Combat Support Hospital (CSH) partnered with Combined Joint Task Force-Operation Inherent Resolve (CJTF-OIR) Surgeon Cell, and Special Operations Joint Task Force-Operation Inherent Resolve (SOJTF-OIR) Surgeon Cell, to introduce the Health Experts onLine Portal (HELP) telemedicine system to medical personnel in Iraq and Syria. HELP is an asynchronous (store and forward) online system that provides secure provider-to-provider teleconsultation services for routine patient care and medical evacuation (MEDEVAC) coordination. The goal was to reduce the need for MEDEVAC by providing expert consultation to medical providers in farther-forward deployed units. Material and Methods In June 2017, the 86th CSH launched HELP telemedicine services for Kuwait. Following the successful implementation of the telemedicine system in Kuwait, the 86th CSH leadership partnered with CJTF-OIR and SOJTF-OIR medical leadership in launching the system within Iraq and Syria as well as making the system available to all deployed locations in Central Command (CENTCOM). This was a prospective cohort study designed to determine if having convenient and secure access to remote subspecialty consultation would be associated with a reduction in routine MEDEVACs from far forward in the battle space. In August 2017, new-user training was completed and the program launched in Iraq and Syria. This study analyzes the baseline MEDEVAC rate in 3 months before the implementation of HELP telemedicine compared to 3 months following the implementation. Results Iraq and Syria cases in the HELP telemedicine system accounted for 17.2% (76) of total CENTCOM telemedicine case volume over the 7-month study period. Comparing the 3-month period before and after implementation of HELP, use of asynchronous telemedicine in Iraq and Syria was associated with a reduction in total MEDEVACs from 157 to 68 (56.7% reduction, p < 0.001). DNBI represented the majority of the change, (65.0% reduction, p < 0.001). MEDEVAC for battle-related injuries decreased slightly from 13 to 6 per 3-month period (p = 0.03). Conclusions This is the first prospective study to demonstrate an association between the initiation of asynchronous telemedicine capabilities in a combat zone and decreased MEDEVACs. Annualized numbers would predict a reduction of 328 MEDEVACs/year for each 10,000 personnel by utilizing asynchronous telemedicine. This represents a significant potential cost savings of $1.2 million/year through avoidance of routine medical movement of personnel and supports unit readiness by retaining service members in areas of combat operations.
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Sheane, Barry J., Arane Thavaneswaran, Dafna D. Gladman, and Vinod Chandran. "Attainment of Minimal Disease Activity Using Methotrexate in Psoriatic Arthritis." Journal of Rheumatology 43, no. 9 (July 15, 2016): 1718–23. http://dx.doi.org/10.3899/jrheum.160111.
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Objective.An international task force has recommended that disease remission or minimal disease activity (MDA) be the target of treatment for psoriatic arthritis (PsA) and that remission or MDA should be attained within 6 months of initiating medication. The aim of this study was to establish the proportion of patients with PsA who achieve MDA after 6 months of methotrexate (MTX) treatment.Methods.Patients who initiated MTX and were naive to biologics between 2004 and 2014 were included. The primary outcome was the achievement of MDA after 6 months of MTX, defined as the presence of at least 5 out of the following 7: tender joint count ≤ 1, swollen joint count (SJC) ≤ 1, Psoriasis Area Severity Index (PASI) ≤ 1 or body surface area ≤ 3%, tender entheseal points ≤ 1, Health Assessment Questionnaire score ≤ 0.5, patient global disease activity visual analog scale (VAS) score ≤ 20, and patient pain VAS ≤ 15. Of 204 patients identified, 167 were treated with MTX for at least 3 months and had sufficient data for analysis at 6 months.Results.At 6 months, 29 patients (17.4%) achieved MDA; 97 patients (58.1%) achieved an SJC ≤ 1 and 138 (82.6%) a PASI ≤ 1. Only 22 (13.2%) achieved the patient global disease activity criterion. Lower back pain and dactylitis were associated with a lower probability of achieving MDA.Conclusion.MTX use achieves MDA by 6 months in < 20% of patients. This compares unfavorably with data for tumor necrosis factor inhibitor use.
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Ghram, Amine, James D. Young, Rahman Soori, and David G. Behm. "Unilateral Knee and Ankle Joint Fatigue Induce Similar Impairment to Bipedal Balance in Judo Athletes." Journal of Human Kinetics 66, no. 1 (March 27, 2019): 7–18. http://dx.doi.org/10.2478/hukin-2018-0063.
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Abstract The purpose of this study was to compare the effects of unilateral ankle fatigue versus the knee muscles with and without vision on bipedal postural control. Elite judo athletes who competed at the national level with at least 10 years of training experience, were randomised into KNEE (n = 10; 20 ± 2 years) and ANKLE (n = 9; 20 ± 3 years) groups, who performed dynamic isokinetic fatiguing contractions (force decreased to 50% of initial peak torque for three consecutive movements) of the knee flexors and extensors or ankle dorsiflexors and plantar flexors, respectively. Static bipedal postural control (French Posturology Association normative standards) with eyes open and eyes closed was examined before and immediately after the fatiguing task. Postural variables examined were the centre of pressure (CoP) sway in the medio-lateral and antero-posterior directions, total CoP area sway and CoP sway velocity. Although unilateral ankle and knee fatigue adversely affected all bipedal postural measures, with greater disturbances with eyes closed, there were no significant main group or interaction effects between KNEE and ANKLE groups. Unilateral lower limb fatigue adversely affected bipedal balance, with knee extension/flexion fatigue affecting bipedal postural control to a similar extent as unilateral ankle dorsiflexion/plantar flexion fatigue. Hence unilateral fatigue can affect subsequent bilateral performance or also have implications for rehabilitation exercise techniques. Our findings may be limited to judo athletes as other populations were not tested.
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Manchikanti, Laxmaiah. "Comprehensive Review of Neurophysiologic Basis and Diagnostic Interventions in Managing Chronic Spinal Pain." Pain Physician 4;12, no. 4;7 (July 14, 2009): E71—E121. http://dx.doi.org/10.36076/ppj.2009/12/e121.
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Background: Understanding the neurophysiological basis of chronic spinal pain and diagnostic interventional techniques is crucial in the proper diagnosis and management of chronic spinal pain.Central to the understanding of the structural basis of chronic spinal pain is the provision of physical diagnosis and validation of patient symptomatology. It has been shown that history, physical examination, imaging, and nerve conduction studies in non-radicular or discogenic pain are unable to diagnose the precise cause in 85% of the patients. In contrast, controlled diagnostic blocks have been shown to determine the cause of pain in as many as 85% of the patients. Objective: To provide evidence-based clinical practice guidelines for diagnostic interventional techniques. Design: Best evidence synthesis. Methods: Strength of evidence was assessed by the U.S. Preventive Services Task Force (USPSTF) criteria utilizing 5 levels of evidence ranging from Level I to III with 3 subcategories in Level II. Diagnostic Criteria: Diagnostic criteria established by systematic reviews were utilized with controlled diagnostic blocks. Diagnostic criteria included at least 80% pain relief with controlled local anesthetic blocks with the ability to perform multiple maneuvers which were painful prior to the diagnostic blocks for facet joint and sacroiliac joint blocks, whereas for provocation discography, the criteria included concordant pain upon stimulation of the target disc with 2 adjacent discs producing no pain at all. Results: The indicated level of evidence for diagnostic lumbar, cervical, and thoracic facet joint nerve blocks is Level I or II-1. The indicated evidence is Level II-2 for lumbar and cervical discography, whereas it is Level II-3 for thoracic provocation discography. The evidence for diagnostic sacroiliac joint nerve blocks is Level II-2. Level of evidence for selective nerve root blocks for diagnostic purposes is Level II-3. Limitations: Limitations of this guideline preparation include a continued paucity of literature and conflicts in preparation of systematic reviews and guidelines. Conclusion: These guidelines include the evaluation of evidence for diagnostic interventional procedures in managing chronic spinal pain and recommendations. However, these guidelines do not constitute inflexible treatment recommendations. These guidelines also do not represent a “standard of care.” Key words: Diagnostic interventional techniques, chronic spinal pain, facet joint interventions, epidural procedures, provocation discography, sacroiliac joint blocks, post lumbar surgery syndrome, spinal stenosis, provocation discography
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Sinclair, R. J., and H. Burton. "Neuronal activity in the second somatosensory cortex of monkeys (Macaca mulatta) during active touch of gratings." Journal of Neurophysiology 70, no. 1 (July 1, 1993): 331–50. http://dx.doi.org/10.1152/jn.1993.70.1.331.
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1. In penetrations made into the upper bank of the lateral sulcus in two monkeys (Macaca mulatta), cells were isolated from the second somatosensory cortex (SII). During single-cell recordings, animals performed an active touch task in which they rubbed their fingertips over pairs of gratings differing in groove width and indicated which was the smoother surface. Hand motion and downward applied force were measured and recorded during these strokes. 2. In this survey, 151 penetrations provided observations on 352 cells that responded to passive stimulation of the digits or during performance of the active touch task. Consistent with previous reports, receptive fields (RFs) in SII were large, often multi-digit, and frequently included a portion or all of the hand and occasionally the arm. Modality was determined for 92 of 127 fully characterized cells, and included 70 cutaneous, 5 deep, 11 Pacinian corpuscle, and 6 joint cells. Characteristic of SII, modality could not be defined in 35 cells that were unresponsive to passive stimulation or whose responses varied widely over time. 3. Response properties of a subgroup of 79 cells in SII resembled those previously studied in the primary somatosensory cortex (SI) and ventroposterior lateral nucleus of the thalamus (VPL) using identical procedures. Correlation analysis revealed that 29 of these cells, like a portion of cells in SI, responded to changes in groove width independent of force or velocity. This selectivity could be considered a form of feature specificity. 4. In contrast to SI and VPL, transient responses to the fingertips contacting small elevated metal bars, which demarcated the beginning, middle, and end of strokes across the gratings, were seen in a majority of SII cells (109/127). During contact with bars, 89 cells displayed excitatory responses and 20 cells showed suppressed activity. Twelve cells, which responded to bars in isolation from gratings, provided a possible example of increased stimulus selectivity. 5. Passive stimulation failed to activate 16 cells that responded, in some cases differentially to gratings or force, during the task. Responses of nine other cells demonstrated task-dependent modulation in the form of response reduction or enhancement during selected portions of the stroke. In these same cells, response changes did not occur under comparable stimulus conditions in other portions of the stroke that differed only in behavioral context. These types of selective response modulations, not noted in our previous studies of VPL or SI, suggest that mechanisms regulating sensory inputs may affect SII.(ABSTRACT TRUNCATED AT 400 WORDS)
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Maas, Huub, Robert J. Gregor, Emma F. Hodson-Tole, Brad J. Farrell, and Boris I. Prilutsky. "Distinct muscle fascicle length changes in feline medial gastrocnemius and soleus muscles during slope walking." Journal of Applied Physiology 106, no. 4 (April 2009): 1169–80. http://dx.doi.org/10.1152/japplphysiol.01306.2007.
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On the basis of differences in physiology, e.g., histochemical properties and spindle density, and the structural design of the cat soleus (SO) and medial gastrocnemius (MG) muscles, we hypothesized that 1) fascicle length changes during overground walking would be both muscle and slope dependent, which would have implications for the muscles' force output as well as sensory function, and that 2) muscle-tendon unit (MTU) and fascicle length changes would be different, in which case MTU length could not be used as an indicator of muscle spindle strain. To test these hypotheses, we quantified muscle fascicle length changes and compared them with length changes of the whole MTU in the SO and MG during overground walking at various slopes (0, ± 25, ± 50, +75, and +100%). The SO and MG were surgically instrumented with sonomicrometry crystals and fine-wire electromyogram electrodes to measure changes in muscle fascicle length and muscle activity, respectively. MTU lengths were calculated using recorded ankle and knee joint angles and a geometric model of the hindlimb. The resultant joint moments were calculated using inverse dynamics analysis to infer muscle loading. It was found that although MTU length and velocity profiles of the SO and MG appeared similar, length changes and velocities of muscle fascicles were substantially different between the two muscles. Fascicle length changes of both SO and MG were significantly affected by slope intensity acting eccentrically in downslope walking (−25 to −50%) and concentrically in upslope walking (+25 to +100%). The differences in MTU and fascicle behaviors in both the SO and MG muscles during slope walking were explained by the three distinct features of these muscles: 1) the number of joints spanned, 2) the pennation angle, and 3) the in-series elastic component. It was further suggested that the potential role of length feedback from muscle spindles is both task and muscle dependent.