To see the other types of publications on this topic, follow the link: Kinematic ankle model.
Journal articles on the topic 'Kinematic ankle model'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Kinematic ankle model.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Chen, Lu Min, Zhi Zhong Zhu, Qi Lin, and Xin Jie Wang. "Design and Kinematics of a Cable-Driven Humanoid Ankle Joint." Applied Mechanics and Materials 541-542 (March 2014): 846–51. http://dx.doi.org/10.4028/www.scientific.net/amm.541-542.846.
Full textAbstract:
A 2DOF ankle joint mechanism with cross rotation axis was designed to imitate the human ankle joint structure. The kinematic model of the ankle joint mechanism was established by D-H method. The synergistic influences of the angle of ankle joint and subtalar joint on the foot motion of inversion/eversion, adduction/abduction, dorsiflexion/plantar flexion were analyzed by kinematics simulation. The simulation results show that the designed ankle joint has similar motion range and function to that of human ankle. This study provides a theoretical basis for the development of high performance ankle joint for humanoid robots.
2
Dul, J., and G. E. Johnson. "A kinematic model of the human ankle." Journal of Biomedical Engineering 7, no. 2 (April 1985): 137–43. http://dx.doi.org/10.1016/0141-5425(85)90043-3.
Full text
3
Rosenberg, Michael C., Bora S. Banjanin, Samuel A. Burden, and Katherine M. Steele. "Predicting walking response to ankle exoskeletons using data-driven models." Journal of The Royal Society Interface 17, no. 171 (October 2020): 20200487. http://dx.doi.org/10.1098/rsif.2020.0487.
Full textAbstract:
Despite recent innovations in exoskeleton design and control, predicting subject-specific impacts of exoskeletons on gait remains challenging. We evaluated the ability of three classes of subject-specific phase-varying (PV) models to predict kinematic and myoelectric responses to ankle exoskeletons during walking, without requiring prior knowledge of specific user characteristics. Each model—PV, linear PV (LPV) and nonlinear PV (NPV)—leveraged Floquet theory to predict deviations from a nominal gait cycle due to exoskeleton torque, though the models differed in complexity and expected prediction accuracy. For 12 unimpaired adults walking with bilateral passive ankle exoskeletons, we predicted kinematics and muscle activity in response to three exoskeleton torque conditions. The LPV model's predictions were more accurate than the PV model when predicting less than 12.5% of a stride in the future and explained 49–70% of the variance in hip, knee and ankle kinematic responses to torque. The LPV model also predicted kinematic responses with similar accuracy to the more-complex NPV model. Myoelectric responses were challenging to predict with all models, explaining at most 10% of the variance in responses. This work highlights the potential of data-driven PV models to predict complex subject-specific responses to ankle exoskeletons and inform device design and control.
4
Speers, Rosemary A., Neil T. Shepard, and Arthur D. Kuo. "EquiTest modification with shank and hip angle measurements: differences with age among normal subjects." Journal of Vestibular Research 9, no. 6 (December 1, 1999): 435–44. http://dx.doi.org/10.3233/ves-1999-9605.
Full textAbstract:
The Sensory Organization Test protocol of the EquiTest system (NeuroCom International, Clackamas Oregon) tests utilization of visual, vestibular, and proprioceptive sensors by manipulating the accuracy of visual and/or somatosensory inputs during quiet stance. In the standard Sensory Organization Test, both manipulation of sensory input (sway-referencing) and assessment of postural sway are based on ground reaction forces measured from a forceplate. The purpose of our investigation was to examine the use of kinematic measurements to provide a more direct feedback signal for sway-referencing and for assessment of sway. We compared three methods of sway-referencing: the standard EquiTest method based on ground reaction torque, kinematic feedback based on servo-controlling to shank motion, and a more complex kinematic feedback based on servo-controlling to follow position of the center of mass (COM) as calculated from a two-link biomechanical model. Fifty-one normal subjects (ages 20–79) performed the randomized protocol. When using either shank or COM angle for sway-referencing feedback as compared to the standard EquiTest protocol, the Equilibrium Quotient and Strategy Score assessments were decreased for all age groups in the platform sway-referenced conditions (SOT 4, 5, 6). For all groups of subjects, there were significant differences in one or more of the kinematic sway measures of shank, hip, or COM angle when using either of the alternative sway-referencing parameters as compared to the standard EquiTest protocol. The increased sensitivities arising from use of kinematics had the effect of amplifying differences with age. For sway-referencing, the direct kinematic feedback may enhance ability to reduce proprioceptive information by servo-controlling more closely to actual ankle motion. For assessment, kinematics measurements can potentially increase sensitivity for detection of balance disorders, because it may be possible to discriminate between body sway and acceleration and to determine the phase relationship between ankle and hip motion.
5
Wiese, Dylan, Jessica M. Fritz, Karl Canseco, Carolyn M. Meinerz, Katherine Konop, and Brian C. Law. "Multi-Segment Foot and Ankle Gait Kinematics Following Total Ankle Arthroplasty." Foot & Ankle Orthopaedics 5, no. 4 (October 1, 2020): 2473011420S0048. http://dx.doi.org/10.1177/2473011420s00489.
Full textAbstract:
Category: Ankle Arthritis; Ankle. Introduction/Purpose: Ankle arthritis is a painful disease resulting in limited function, mobility, and quality of life.1 Total ankle arthroplasty (TAA) a widely accepted treatment to reduce pain while maintaining joint motion.2,3 There are two common types of implants: fixed bearing (FB) and mobile bearing (MB). Comparisons of these implants have shown similar patient and clinical outcomes;4 however, post-operative gait kinematics from a multi-segment foot and ankle model have not been compared. This study assessed multi-segmental foot and ankle gait kinematics between persons following TAA with MB and FB implants and compared them to control data of adult ambulators without lower extremity pathology. Methods: This was a prospective analysis of persons who had previously underwent TAA with a MB (n=6; average follow-up period of 2.5 years) implant. After consenting to the IRB-approved study, participants were fitted with reflective markers for the Milwaukee Foot Model (MFM).5 Participants walked barefoot along a 30-foot walkway at a comfortable, self-selected pace for a minimum of ten trials while twelve infrared motion capture cameras recorded data. Kinematic data from the MB group and historical data from a FB population who underwent the same protocol with the MFM (n=7; average follow-up period of 2 years) were compared to control data (n=37). Welch’s two-tailed t-tests were used to calculate statistical significance at an alpha level of 0.05. Deviation from control data was compared between both implant groups. Results: In the MB group, sagittal motion of the hindfoot, forefoot, and hallux were significantly different from control for the majority of stance. The only significant MB group swing phase differences were early swing sagittal kinematics in the tibia, forefoot, and hallux segments. The FB data differed significantly for the majority of stance phase for sagittal tibia motion, all hindfoot planes, sagittal and coronal forefoot motion, and all hallux planes. The FB group kinematics also significantly differed throughout most of swing phase across all planes and segments, except coronal hindfoot motion. All FB kinematic data deviated further from control than the MB data except stance phase coronal tibia and transverse forefoot motion, where the data overlapped (Figure 1). Conclusion: Multi-segment foot and ankle gait kinematics following TAA showed the MB implant better restores healthy ambulatory motion than the FB implant. Abnormal stance phase kinematics lead to altered joint loading. This can accelerate adjacent joint arthritis, which has been seen following ankle arthrodesis.6 Both populations showed diminished forefoot plantarflexion throughout gait, compensating for decreased hindfoot dorsiflexion. Because the joints are not heavily loaded during swing phase, the primary concerns of alterations are regarding ground clearance and foot position prior to the next step. The MB implant better restores normal gait, minimizing compensations and likely decreasing arthritis-inducing stress on adjacent joints.
6
Koga, Hideyuki, Atsuo Nakamae, Yosuke Shima, Roald Bahr, and Tron Krosshaug. "Hip and Ankle Kinematics in Noncontact Anterior Cruciate Ligament Injury Situations: Video Analysis Using Model-Based Image Matching." American Journal of Sports Medicine 46, no. 2 (October 12, 2017): 333–40. http://dx.doi.org/10.1177/0363546517732750.
Full textAbstract:
Background: Detailed kinematic descriptions of real anterior cruciate ligament (ACL) injury situations are limited to the knee only. Purpose: To describe hip and ankle kinematics as well as foot position relative to the center of mass (COM) in ACL injury situations through use of a model-based image-matching (MBIM) technique. The distance between the projection of the COM on the ground and the base of support (BOS) (COM_BOS) normalized to the femur length was also evaluated. Study Design: Descriptive laboratory study. Methods: Ten ACL injury video sequences from women’s handball and basketball were analyzed. Hip and ankle joint kinematic values were obtained by use of MBIM. Results: The mean hip flexion angle was 51° (95% CI, 41° to 63°) at initial contact and remained constant over the next 40 milliseconds. The hip was internally rotated 29° (95% CI, 18° to 39°) at initial contact and remained unchanged for the next 40 milliseconds. All of the injured patients landed with a heel strike with a mean dorsiflexion angle of 2° (95% CI, –9° to 14°), before reaching a flatfooted position 20 milliseconds later. The foot position was anterior and lateral to the COM in all cases. However, none of the results showed larger COM_BOS than 1.2, which has been suggested as a criterion for ACL injury risk. Conclusions: Hip kinematic values were consistent among the 10 ACL injury situations analyzed; the hip joint remained unchanged in a flexed and internally rotated position in the phase leading up to injury, suggesting that limited energy absorption took place at the hip. In all cases, the foot contacted the ground with the heel strike. However, relatively small COM_BOS distances were found, indicating that the anterior and lateral foot placement in ACL injury situations was not different from what can be expected in noninjury game situations.
7
Plaass, Christian, Leif Claassen, Christina Stukenborg-Colsman, Daiwei Yao, Kiriakos Daniilidis, Sarah Ettinger, and Andrej Nowakowski. "Three-dimensional Analysis of the Talocrural Joint Axis." Foot & Ankle Orthopaedics 2, no. 3 (September 1, 2017): 2473011417S0003. http://dx.doi.org/10.1177/2473011417s000331.
Full textAbstract:
Category: Ankle Introduction/Purpose: The total ankle replacement (TAR) is increasingly used in cases of severe ankle arthritis. Although the knowledge about joint kinematics is crucial for designing and positioning of TAR there is no consensus about the talocrural joint axis. The aim of the present study was the determination of the kinematic rotational axis of the talocrural joint as an orientation for prosthesis positioning. Methods: We analyzed 96 CT-scans of full cadaver caucasien legs. With the software Mimic, 3-Matic (both Materialize) and GOM inspect we generated three-dimensional reconstruction models of the talus and a best fitting cone orientated to the talar articular surface. The kinematic rotational axis was defined to be the axis of this cone. Results: The determination of the kinematic rotational axis showed a high inter- and intrarater reliability. The kinematic rotational axis of the talocrural joint is orientated from lateral-distal to medial-proximal (84.9° ± 8.5 compared to mechanical tibial axis in frontal plane), from dorsal-proximal to anterior-distal (93.1° ± 42.3 compared to mechanical tibial axis in sagittal plane) and from dorsal-lateral to anterior-medial (169.0° ± 6.7 compared to mechanical tibial axis in axial plane). A high standard deviation especially in the sagittal plane was noteworthy. Conclusion: With the present study we present a new reproducable single-axis model of the talocrural joint. Our data showed relevant interindividual variations. The consideration of these variations might support the development of patient-specific TAR implantation techniques.
8
Bramah, Christopher, Stephen J. Preece, Niamh Gill, and Lee Herrington. "Is There a Pathological Gait Associated With Common Soft Tissue Running Injuries?" American Journal of Sports Medicine 46, no. 12 (September 7, 2018): 3023–31. http://dx.doi.org/10.1177/0363546518793657.
Full textAbstract:
Background: Previous research has demonstrated clear associations between specific running injuries and patterns of lower limb kinematics. However, there has been minimal research investigating whether the same kinematic patterns could underlie multiple different soft tissue running injuries. If they do, such kinematic patterns could be considered global contributors to running injuries. Hypothesis: Injured runners will demonstrate differences in running kinematics when compared with injury-free controls. These kinematic patterns will be consistent among injured subgroups. Study Design: Controlled laboratory study. Methods: The authors studied 72 injured runners and 36 healthy controls. The injured group contained 4 subgroups of runners with either patellofemoral pain, iliotibial band syndrome, medial tibial stress syndrome, or Achilles tendinopathy (n = 18 each). Three-dimensional running kinematics were compared between injured and healthy runners and then between the 4 injured subgroups. A logistic regression model was used to determine which parameters could be used to identify injured runners. Results: The injured runners demonstrated greater contralateral pelvic drop (CPD) and forward trunk lean at midstance and a more extended knee and dorsiflexed ankle at initial contact. The subgroup analysis of variance found that these kinematic patterns were consistent across each of the 4 injured subgroups. CPD was found to be the most important variable predicting the classification of participants as healthy or injured. Importantly, for every 1° increase in pelvic drop, there was an 80% increase in the odds of being classified as injured. Conclusion: This study identified a number of global kinematic contributors to common running injuries. In particular, we found injured runners to run with greater peak CPD and trunk forward lean as well as an extended knee and dorsiflexed ankle at initial contact. CPD appears to be the variable most strongly associated with common running-related injuries. Clinical Relevance: The identified kinematic patterns may prove beneficial for clinicians when assessing for biomechanical contributors to running injuries.
9
Farley, Claire T., Han H. P. Houdijk, Ciska Van Strien, and Micky Louie. "Mechanism of leg stiffness adjustment for hopping on surfaces of different stiffnesses." Journal of Applied Physiology 85, no. 3 (September 1, 1998): 1044–55. http://dx.doi.org/10.1152/jappl.1998.85.3.1044.
Full textAbstract:
When humans hop in place or run forward, leg stiffness is increased to offset reductions in surface stiffness, allowing the global kinematics and mechanics to remain the same on all surfaces. The purpose of the present study was to determine the mechanism for adjusting leg stiffness. Seven subjects hopped in place on surfaces of different stiffnesses (23–35,000 kN/m) while force platform, kinematic, and electromyographic data were collected. Leg stiffness approximately doubled between the most stiff surface and the least stiff surface. Over the same range of surfaces, ankle torsional stiffness increased 1.75-fold, and the knee became more extended at the time of touchdown (2.81 vs. 2.65 rad). We used a computer simulation to examine the sensitivity of leg stiffness to the observed changes in ankle stiffness and touchdown knee angle. Our model consisted of four segments (foot, shank, thigh, head-arms-trunk) interconnected by three torsional springs (ankle, knee, hip). In the model, an increase in ankle stiffness 1.75-fold caused leg stiffness to increase 1.7-fold. A change in touchdown knee angle as observed in the subjects caused leg stiffness to increase 1.3-fold. Thus both joint stiffness and limb geometry adjustments are important in adjusting leg stiffness to allow similar hopping on different surfaces.
10
Kiemel, Tim, Alexander J. Elahi, and John J. Jeka. "Identification of the Plant for Upright Stance in Humans: Multiple Movement Patterns From a Single Neural Strategy." Journal of Neurophysiology 100, no. 6 (December 2008): 3394–406. http://dx.doi.org/10.1152/jn.01272.2007.
Full textAbstract:
We determined properties of the plant during human upright stance using a closed-loop system identification method originally applied to human postural control by another group. To identify the plant, which was operationally defined as the mapping from muscle activation (rectified EMG signals) to body segment angles, we rotated the visual scene about the axis through the subject's ankles using a sum-of-sines stimulus signal. Because EMG signals from ankle muscles and from hip and lower trunk muscles showed similar responses to the visual perturbation across frequency, we combined EMG signals from all recorded muscles into a single plant input. Body kinematics were described by the trunk and leg angles in the sagittal plane. The phase responses of both angles to visual scene angle were similar at low frequencies and approached a difference of ∼150° at higher frequencies. Therefore we considered leg and trunk angles as separate plant outputs. We modeled the plant with a two-joint (ankle and hip) model of the body, a second-order low-pass filter from EMG activity to active joint torques, and intrinsic stiffness and damping at both joints. The results indicated that the in-phase (ankle) pattern was neurally generated, whereas the out-of-phase pattern was caused by plant dynamics. Thus a single neural strategy leads to multiple kinematic patterns. Moreover, estimated intrinsic stiffness in the model was insufficient to stabilize the plant.
11
Myers, K. A., M. Wang, R. M. Marks, and G. F. Harris. "Validation of a Multisegment Foot and Ankle Kinematic Model for Pediatric Gait." IEEE Transactions on Neural Systems and Rehabilitation Engineering 12, no. 1 (March 2004): 122–30. http://dx.doi.org/10.1109/tnsre.2003.822758.
Full text
12
Di Marco, R., E. Scalona, E. Palermo, and C. Mazzà. "A novel kinematic model of the foot-ankle complex for gait analysis." Gait & Posture 57 (September 2017): 5–6. http://dx.doi.org/10.1016/j.gaitpost.2017.07.053.
Full text
13
Brindle, Timothy J., Jeri L. Miller, Maria K. Lebiedowska, and Steven J. Stanhope. "Gastrocnemius Fascicle Length Changes with Two-Joint Passive Movements." Journal of Applied Biomechanics 24, no. 3 (August 2008): 252–61. http://dx.doi.org/10.1123/jab.24.3.252.
Full textAbstract:
Predicting muscle fascicle length changes during passive movements may lead to a better understanding of muscle function. The purpose of this study was to experimentally compare fascicle length changes in the gastrocnemius during two-joint passive movements with a previously derived kinematic model based on anatomical measures from a cadaver. The ratio of passive ankle to knee motion was manipulated to generate medial gastrocnemius fascicle elongation and lateral gastrocnemius fascicle shortening. Ultrasound images from both heads of the gastrocnemius fascicles were acquired at 10° knee flexion increments and compared with this kinematic model. Our results suggest that the two-joint kinematic model from which we originally based our knee and ankle movements did not adequately reflect fascicle length changes during any of the movement conditions in this study. From our data, we propose that for every degree of ankle motion the medial and lateral gastrocnemius changes 0.42 mm and 0.96 mm, respectively, whereas changes of 0.14 mm and 0.22 mm are observed for the medial and lateral gastrocnemius, respectively, during knee movements.
14
Gittoes, Marianne J. R., David G. Kerwin, and Mark A. Brewin. "Sensitivity of Loading to the Timing of Joint Kinematic Strategies in Simulated Forefoot Impact Landings." Journal of Applied Biomechanics 25, no. 3 (August 2009): 229–37. http://dx.doi.org/10.1123/jab.25.3.229.
Full textAbstract:
The impact loads experienced in landing may be influenced by the joint kinematic strategy used. This study aimed to enhance the understanding of the sensitivity of impact loading to the timing of joint kinematic strategies in simulated forefoot landings. Coordinate and force data of drop landings were used to initiate, drive, and evaluate a wobbling mass model. Ankle, knee, and hip joint angle profile timings were modified in the simulated motions. Changes to the timing of the ankle and knee joint angle profiles were associated with substantial changes in the peak vertical ground reaction force (GFzmax) of up to 3.9 body-weights (BW) and 1.5 BW, respectively, whereas loading was less sensitive to temporal changes in the hip joint strategy. Accentuated impact loads incurred by a modified knee flexion action may be explained by the need to maintain an ordered and controlled load attenuation strategy. Individual strategies and external and joint reaction forces should be considered for developing insight into loading in impact landings.
15
Cabarkapa, Dimitrije, Andrew C. Fry, John P. Poggio, and Michael A. Deane. "KINEMATIC DIFFERENCES BETWEEN PROFICIENT AND NON-PROFICIENT FREE THROW SHOOTERS – VIDEO ANALYSIS." Journal of Applied Sports Sciences 1, no. 2021 (July 20, 2021): 12–21. http://dx.doi.org/10.37393/jass.2021.01.2.
Full textAbstract:
Despite its importance and significant contribution to the final game outcome, the free throw shooting motion is greatly understudied. The purpose of this study was to examine kinematic differences between proficient and non-proficient free throw shooters and to determine which variables have the greatest impact on successful free throw shooting performance. Thirteen healthy recreationally active males volunteered to participate in this study. Each participant shot three sets of ten consecutive free throws from the regulation distance from the basket. Each set was performed under 3 minutes with 1-2-minute rest between each set. A high-definition camera recording at 30 fps captured the free throw shooting motion from a sagittal point of view. Video analysis software was used to analyze the following kinematic variables: knee angle, elbow angle, hip flexion, ankle flexion, release angle, shoulder angle, hand release height, and elbow height. The findings of this study suggest that lower elbow positioning influenced by greater knee, ankle, and hip flexion during the preparatory phase of the shooting motion may lead to improvements in free throw shooting accuracy. Moreover, greater ball release height and release angle, as previously suggested, could decrease the margin of error and enhance free throw shooting performance. By using these kinematic variables to create the discriminant function projection model, it is plausible that proficient free throw shooters can be accurately classified in 94% of cases.
16
Yang, Pei-Lin, and Lai-Hsing Hsu. "DIMENSIONLESS ANALYSIS OF HUMAN LOWER LIMB." Transactions of the Canadian Society for Mechanical Engineering 29, no. 3 (September 2005): 423–40. http://dx.doi.org/10.1139/tcsme-2005-0026.
Full textAbstract:
This study derives a dimensionless kinematic model using a coordinate transformation matrix to analyze the kinematic characteristics of human lower limb. The lower limb model in this study considers three segments including the thigh, shank and foot, and three joints, namely the hip, knee, ankle and the two extremes of the foot, namely the heel and toe. Based on the dimensionless analysis model ignoring human stature, the kinematic characteristics of lower limb can be described by the relationships of the dimensionless displacements, velocities and accelerations with respect to dimensionless time. The results of an experimental data have shown that dimensionless kinematic characteristics follow the same trends as current gait analysis. This study proposed a dimensionless kinematic model that is capable of analyzing kinematic characteristics of lower limb joints. In the future, this model is anticipated to investigate the dynamics of gait and clinical application.
17
Dong, Mingjie, Yuan Kong, Jianfeng Li, and Wenpei Fan. "Kinematic Calibration of a Parallel 2-UPS/RRR Ankle Rehabilitation Robot." Journal of Healthcare Engineering 2020 (September 3, 2020): 1–12. http://dx.doi.org/10.1155/2020/3053629.
Full textAbstract:
In order to better perform rehabilitation training on the ankle joint complex in the direction of dorsiflexion/plantarflexion and inversion/eversion, especially when performing the isokinetic muscle strength exercise, we need to calibrate the kinematic model to improve its control precision. The ankle rehabilitation robot we develop is a parallel mechanism, with its movements in the two directions driven by two linear motors. Inverse solution of positions is deduced and the output lengths of the two UPS kinematic branches are calibrated in the directions of dorsiflexion, plantarflexion, inversion, and eversion, respectively. Motion of each branch in different directions is fitted in high-order form according to experimental data. Variances, standard deviation, and goodness of fit are taken into consideration when choosing the best fitting curve, which ensures that each calibration can match the most appropriate fitting curve. Experiments are conducted to verify the effectiveness of the kinematic calibration after finishing the calibration, and the errors before and after calibration of the two kinematic chains in different directions are compared, respectively, which shows that the accuracy after calibration has been significantly improved.
18
Mattes, Klaus, Stefanie Wolff, and Shahab Alizadeh. "Kinematic Stride Characteristics of Maximal Sprint Running of Elite Sprinters – Verification of the “Swing-Pull Technique”." Journal of Human Kinetics 77, no. 1 (January 30, 2021): 15–24. http://dx.doi.org/10.2478/hukin-2021-0008.
Full textAbstract:
Abstract Maximum sprinting speed constitutes an optimum relation between the stride length and the step rate in addition to an appropriate sprinting technique. The kinematics of the sprint step at maximum sprinting speed have already been examined in numerous studies, without reaching a consensus. The aim of this study was to analyze the relationship between maximum sprinting speed and the stride kinematics based on the “Swing-Pull Technique”. German elite sprinters (N = 26, body height = 182 ± 6 cm, leg length 93.8 ± 4.1 cm) were tested while performing a 30-meter flying sprint at maximum sprinting speed. The relationship between sprinting speed and kinematic variables was determined via Pearson correlation. Sprinting speed (10.1 – 11.3 m/s) correlated with stride length (r = 0.53), ground contact time (r = -0.53) and variables from the technique model: the knee angle at the end of the knee lift swing (r = 0.40), the maximum knee angle prior to backswing (r = 0.40), the hip extension angle velocity (r = 0.63), and vertical foot velocity (r = 0.77) during pre-support, the ankle angle at the take-on (r = -0.43), knee flexion (r = -0.54), and knee extension (r = -0.47) during support. The results indicate that greater stride length, smaller contact time, and the mentioned kinematic step characteristics are relevant for the production of maximum sprinting speed in athletes at an intermediate to advanced performance level. The association of sprinting speed and these features should primarily be taken into account in conditioning and technical training.
19
Pinter, Ilona J., Roos van Swigchem, A. J. Knoek van Soest, and Leonard A. Rozendaal. "The Dynamics of Postural Sway Cannot Be Captured Using a One-Segment Inverted Pendulum Model: A PCA on Segment Rotations During Unperturbed Stance." Journal of Neurophysiology 100, no. 6 (December 2008): 3197–208. http://dx.doi.org/10.1152/jn.01312.2007.
Full textAbstract:
Research on unperturbed stance is largely based on a one-segment inverted pendulum model. Recently, an increasing number of studies report a contribution of other major joints to postural control. Therefore this study evaluates whether the conclusions originating from the research based on a one-segment model adequately capture postural sway during unperturbed stance. High-pass filtered kinematic data (cutoff frequency 1/30 Hz) obtained over 3 min of unperturbed stance were analyzed in different ways. Variance of joint angles was analyzed. Principal-component analysis (PCA) was performed on the variance of lower leg, upper leg, and head–arms–trunk (HAT) angles, as well as on lower leg and COM angle (the orientation of the line from ankle joint to center of mass). It was found that the variance in knee and hip joint angles did not differ from the variance found in the ankle angle. The first PCA component indicated that, generally, the upper leg and HAT segments move in the same direction as the lower leg with a somewhat larger amplitude. The first PCA component relating ankle angle variance and COM angle variance indicated that the ankle joint angle displacement gives a good estimate of the COM angle displacement. The second PCA component on the segment angles partly explains the apparent discrepancy between these findings because this component points to a countermovement of the HAT relative to the ankle joint angle. It is concluded that postural control during unperturbed stance should be analyzed in terms of a multiple inverted pendulum model.
20
Park, Jihong, Matthew K. Seeley, Devin Francom, C. Shane Reese, and J. Ty Hopkins. "Functional vs. Traditional Analysis in Biomechanical Gait Data: An Alternative Statistical Approach." Journal of Human Kinetics 60, no. 1 (December 28, 2017): 39–49. http://dx.doi.org/10.1515/hukin-2017-0114.
Full textAbstract:
Abstract In human motion studies, discrete points such as peak or average kinematic values are commonly selected to test hypotheses. The purpose of this study was to describe a functional data analysis and describe the advantages of using functional data analyses when compared with a traditional analysis of variance (ANOVA) approach. Nineteen healthy participants (age: 22 ± 2 yrs, body height: 1.7 ± 0.1 m, body mass: 73 ± 16 kg) walked under two different conditions: control and pain+effusion. Pain+effusion was induced by injection of sterile saline into the joint capsule and hypertonic saline into the infrapatellar fat pad. Sagittal-plane ankle, knee, and hip joint kinematics were recorded and compared following injections using 2×2 mixed model ANOVAs and FANOVAs. The results of ANOVAs detected a condition × time interaction for the peak ankle (F1,18 = 8.56, p = 0.01) and hip joint angle (F1,18 = 5.77, p = 0.03), but did not for the knee joint angle (F1,18 = 0.36, p = 0.56). The functional data analysis, however, found several differences at initial contact (ankle and knee joint), in the mid-stance (each joint) and at toe off (ankle). Although a traditional ANOVA is often appropriate for discrete or summary data, in biomechanical applications, the functional data analysis could be a beneficial alternative. When using the functional data analysis approach, a researcher can (1) evaluate the entire data as a function, and (2) detect the location and magnitude of differences within the evaluated function.
21
Smith, Bryan, Adam Schiff, Robert Havey, Michael Pinzur, and Muturi Muriuki. "Peritalar Motion after Simulated Ankle Fusion in a Cadaveric Model." Foot & Ankle Orthopaedics 4, no. 4 (October 1, 2019): 2473011419S0039. http://dx.doi.org/10.1177/2473011419s00398.
Full textAbstract:
Category: Ankle Arthritis, Basic Sciences/Biologics Introduction/Purpose: Adjacent joint disease often occurs after many orthopaedic surgical interventions. Specifically in the foot and ankle, subtalar arthritis has been demonstrated as a long term sequelae after ankle arthrodesis. The purpose of this study was to evaluate real time qualitative and quantitative motion differences in the hindfoot and midfoot during simulated gait, both before and after ankle fusion in a cadaveric model. Data recorded from each cadaveric trial is used in conjunction with a CT scan of each specimen, allowing creation of a three-dimensional, real time, anatomic model of motion of the foot and ankle. Methods: Three human cadaveric specimens (lower leg and foot) were obtained and prepared for testing. Taking care to preserve the ligamentous and tendinous attachments, radiopaque fiducial makers were placed in each bone (tibia, fibula, talus, calcaneus, navicular, all cuneiforms, 1st metatarsal). CT scan of each specimen was then performed, and used to develop a three dimensional anatomic model of the specimen. Each specimen was then mounted into a custom built apparatus, and load was applied to the construct using a follower load model. Each specimen was taken through two full cycles of the simulated stance phase. Kinematic data of the individual bones/joints were measured in real time, using optoelectronic targets, and saved for later comparison. Next, tibiotalar fusion was performed on each of the previously tested specimens using an anterior plate and screw construct. The specimens were again cycled in the same fashion and data was recorded in the same manner. Results: Tibiotalar fusion successfully eliminated motion between the talus and tibia, directly altering the normal kinematics of the foot ankle complex. Quantitatively, the motion at the subtalar and talonavicular joints increased only slightly with fusion. However, this represents a relative increased motion demand at each joint that exceeds what was observed in the non-fusion condition. Qualitatively, the motion curves for the talocalcaneal and talonavicular joints were altered when compared to the non-fusion state (Figure 1). The qualitative change in motion revealed a relative linkage of motion between the subtalar and talonavicular joints and this was consistently observed across all specimens. Conclusion: Simulated ankle fusion via an anterior plate and screw construct directly alters the kinematics of the downstream (talocalcaneal and talonavicular) joints. Real time observation demonstrates a relative linkage of the motion occurring in the subtalar and talonavicular joints. This linkage resulted in alteration from the observed physiologic motion that occurred in these joints during the non-fusion condition. These findings may provide insight into the etiology of adjacent segment disease seen in the subtalar and talonavicular joints after ankle fusion.
22
AGUIAR, LILIANA, CARLOS ANDRADE, MARCO BRANCO, RITA SANTOS-ROCHA, FILOMENA VIEIRA, and ANTÓNIO VELOSO. "GLOBAL OPTIMIZATION METHOD APPLIED TO THE KINEMATICS OF GAIT IN PREGNANT WOMEN." Journal of Mechanics in Medicine and Biology 16, no. 06 (September 2016): 1650084. http://dx.doi.org/10.1142/s0219519416500846.
Full textAbstract:
Morphological changes are associated to pregnancy, such as weight gain and increased volume of the trunk. The soft tissue artifact can also increase with these characteristics and affect the real joint kinematics. The main objective of this study was to understand the effect of using three different constraining sets in the lower limb joints, in the amount of soft tissue artifact (STA) of pregnant women, in order to obtain the most appropriated joint set to be used in gait and in this population. The ankle, knee and hip joints were modeled respectively with the following characteristics: (1) Universal–revolute–spherical (URS), (2) spherical–revolute–spherical (SRS) and (3) spherical–spherical–spherical (SSS). The six degrees of freedom (6DOF) model was used as the basis for comparison and considered the one with the highest error associated to the STA. In pregnant women, the URS model seems to affect more the kinematic variables when compared with the 6DOF model. Assuming that the kinematic error associated with pregnant women is increased due to the STA, the URS model may be affecting more the angular kinematics of the knee joint. SSS model seems to be more appropriated to analyze gait in second trimester pregnant women.
23
Castelli, Andrea, Gabriele Paolini, Andrea Cereatti, and Ugo Della Croce. "A 2D Markerless Gait Analysis Methodology: Validation on Healthy Subjects." Computational and Mathematical Methods in Medicine 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/186780.
Full textAbstract:
A 2D markerless technique is proposed to perform lower limb sagittal plane kinematic analysis using a single video camera. A subject-specific, multisegmental model of the lower limb was calibrated with the subject in an upright standing position. Ankle socks and underwear garments were used to track the feet and pelvis segments, whereas shank and thigh segments were tracked by means of reference points identified on the model. The method was validated against a marker based clinical gait model. The accuracy of the spatiotemporal parameters estimation was found suitable for clinical use (errors between 1% and 3% of the corresponding true values). Comparison analysis of the kinematics patterns obtained with the two systems revealed high correlation for all the joints(0.82<R2<0.99). Differences between the joint kinematics estimates ranged from 3.9 deg to 6.1 deg for the hip, from 2.7 deg to 4.4 deg for the knee, and from 3.0 deg to 4.7 deg for the ankle. The proposed technique allows a quantitative assessment of the lower limb motion in the sagittal plane, simplifying the experimental setup and reducing the cost with respect to traditional marker based gait analysis protocols.
24
Mohan Varma, D. S., and S. Sujatha. "Segmental contributions to the ground reaction force in the single support phase of gait." Mechanical Sciences 5, no. 2 (August 19, 2014): 37–52. http://dx.doi.org/10.5194/ms-5-37-2014.
Full textAbstract:
Abstract. An inverse dynamics model for the single support (SS) phase of gait is developed to study segmental contributions to the ground reaction force (GRF). With segmental orientations as the generalized degrees of freedom (DOF), the acceleration of the body's center-of-mass is expressed analytically as the summation of the weighted kinematics of individual segments. The weighting functions are constants that are functions of the segment masses and center-of-mass distances. Using kinematic and anthropometric data from literature as inputs, and using the roll-over-shape (ROS) to model the foot-ground interaction, GRF obtained from the inverse model are compared with measured GRF data from literature. The choice of the generalized coordinates and mathematical form of the model provides a means to weigh individual segment contributions, simplify models and choose more kinetically accurate inverse dynamics models. For the kinematic data used, an anthropomorphic model that includes the frontal plane rotation of the pelvis in addition to the sagittal DOF of the thigh and shank most accurately captures the vertical component of the GRF in the SS phase of walking. Of the two ROS used, the ankle-foot roll-over shape provides a better approximation of the kinetics in the SS phase. The method presented here can be used with additional experimental studies to confirm these results.
25
Munadi, Munadi, Ismoyo Haryanto, and Toni Prahasto. "ANALISA KINEMATIK, DINAMIK DAN METODE GERAK KAKI MODEL SNOOPER HEXAPOD ROBOT." ROTASI 17, no. 3 (July 1, 2015): 137. http://dx.doi.org/10.14710/rotasi.17.3.137-144.
Full textAbstract:
This article presents how to make a model of snooper hexapod robot as a legged robot which is inspired by the spider. This model robot is used for monitoring systems of an industrial area. We design an hexapod robot that consists of 18 dof, which it used acrylic as a base material, servomotor as a driver and an ATmega 128 as microcontroller. We start to make a mechanical design of a snooper hexapod robot construction. Furthermore, kinematics and dynamics analysis of hexapod robot is discussed using Matlab from the control point of view. The objective of kinematic analysis is to determine the kinematic quatities such as displacements, velocities, and accelerations of the elements of model robot when the input motion is given. It establishes the relationship between the motions of various components of the link. The dynamics analysis will inform a torque at the joint ankle hexapod robot using modeling Matlab Simmechanics. The model of hexapod robot is used for monitoring systems so called snooper hexapod will be designed and manufactured so have the required capabilities as a surveillance robot that is able to reach the difficult area and can transmit visual information to the operators who control it. Analysis is done on the robot motion algorithm on three kinds of methods of walk (one wave, two wave, and tripod) with few parameters specified
26
Gatt, Alfred, Nachiappan Chockalingam, and Thierry Larose Chevalier. "Sagittal plane kinematics of the foot during passive ankle dorsiflexion." Prosthetics and Orthotics International 35, no. 4 (October 5, 2011): 425–31. http://dx.doi.org/10.1177/0309364611420476.
Full textAbstract:
Background: Measurement of ankle joint dorsiflexion is an essential examination technique that needs to be performed prior to prescription of foot orthoses since the presence or absence of ankle equinus will affect the design of such devices. The purpose of this study was to investigate the effect of foot posture on sagittal plane kinematics of various foot segments during passive dorsiflexion. Study Design: Comparative repeated measures design. Objectives: To determine the effect of foot posture on inter segmental kinematics during passive dorsiflexion. Methods: An optoelectronic movement analysis system was employed to collect kinematic data. A validated marker set (Oxford Foot Model) was applied to 16 subjects (12 males, 4 females) with a mean age of 35.5 years (range 20–56 years), who provided informed consent. An upward force was applied to the forefoot until maximum resistance. Sagittal movement of the hindfoot and forefoot segments along with the whole foot movement were analyzed in the pronated, neutral and supinated foot postures. Results: While maximum foot dorsiflexion angle showed a significant difference between the three postures ( p=0.000) the actual recorded difference between the neutral and supinated postures was only 2.49°. For the hindfoot and forefoot segments, mean angle range of movement for the pronated foot posture was significantly higher than the other foot postures. The forefoot to hindfoot angle demonstrated a significant ( p=0.005) increase during dorsiflexion between the pronated and supinated postures. These results indicate that during passive dorsiflexion, the forefoot travels through a greater degree of movement than the hindfoot. Conclusions: While the maximum foot dorsiflexion angle differs significantly between the pronated and supinated foot postures, hindfoot movement also varies significantly between foot postures. Furthermore, the forefoot to tibia angle travels through a greater range than the hindfoot to tibia angle, in all three foot postures. The hindfoot to forefoot angle does not remain constant during passive dorsiflexion, but increases upon application of a dorsiflexing force, indicating that the forefoot movement cannot be eliminated completely by placing the foot in any particular posture.
27
Glowinski, Sebastian, Tomasz Krzyzynski, Aleksandra Bryndal, and Igor Maciejewski. "A Kinematic Model of a Humanoid Lower Limb Exoskeleton with Hydraulic Actuators." Sensors 20, no. 21 (October 27, 2020): 6116. http://dx.doi.org/10.3390/s20216116.
Full textAbstract:
Although it is well-established that exoskeletons as robots attached to the extremities of the human body increase their strength, limited studies presented a computer and mathematical model of a human leg hydraulic exoskeleton based on anthropometric data. This study aimed to examine lower limb joint angles during walking and running by using Inertial Measurement Units. The geometry and kinematic parameters were calculated. Twenty-six healthy adults participated in walking and running experiments. The geometric model of a human leg hydraulic exoskeleton was presented. Joint angle data acquired during experiments were used in the mathematical model. The position and velocity of exoskeleton actuators in each phase of movement were calculated using the MATLAB package (Matlab_R2017b, The MathWorks Company, Novi, MI, USA). The highest velocity of the knee actuator during walking and running was in the swing phase, 0.3 and 0.4 m/s, respectively. For the ankle and hip joints, the highest velocity of actuators occurred during the push-off phase. The results with 26 healthy subjects demonstrated that the system's compliance can be effectively adjusted while guiding the subjects walking in predefined trajectories. The developed mathematical model makes it possible to determine the position of lower limb segments and exoskeleton elements. The proposed model allows for calculating the position of the human leg and actuators’ characteristic points.
28
Alleva, Stefano, Michele Gabrio Antonelli, Pierluigi Beomonte Zobel, and Francesco Durante. "Biomechanical Design and Prototyping of a Powered Ankle-Foot Prosthesis." Materials 13, no. 24 (December 19, 2020): 5806. http://dx.doi.org/10.3390/ma13245806.
Full textAbstract:
Powered ankle-foot prostheses for walking often have limitations in the range of motion and in push-off power, if compared to a lower limb of a healthy person. A new design of a powered ankle-foot prosthesis is proposed to obtain a wide range of motion and an adequate power for a push-off step. The design methodology for this prosthesis has three points. In the first one, a dimensionless kinematic model of the lower limb in the sagittal plane is built, through an experimental campaign with healthy subjects, to calculate the angles of lower limb during the gait. In the second point a multibody inverse dynamic model of the lower limb is constructed to calculate the foot-ground contact force, its point of application and the ankle torque too, entering as input data the calculated angles of the lower limb in the previous point. The third point requires, as input of the inverse dynamic model, the first dimensioning data of the ankle-foot prosthesis to obtain the load acting on the components of the prosthesis and the angle torque of the actuator during the gait cycle. Finally, an iteration cycle begins with the inverse dynamic model modifying the ankle torque and angle until these quantities during the gait are as close as possible to the physiological quantities. After the mechanical design and the construction of the prototype of the prosthesis, an experimental methodology was used for preliminary validation of the design. The preliminary tests in the laboratory on the prototype alone show that the range of motion of the ankle angle during the gait is close to a healthy person’s: 27.6° vs. 29°. The pushing force of the distal area of the prototype is 1.000 N, instead of 1.600 N, because a budget reduction forced us to choose components for the prototype with lower performance.
29
Lee, Seung Yeol, Kyoung min Lee, Soon-Sun Kwon, and Sangho Chun. "Influence of surgery involving tendons around the knee joint on ankle motion during gait in patients with cerebral palsy." Foot & Ankle Orthopaedics 2, no. 3 (September 1, 2017): 2473011417S0002. http://dx.doi.org/10.1177/2473011417s000258.
Full textAbstract:
Category: Ankle Introduction/Purpose: The gastrocnemius, a biarticular muscle that crosses the knee and ankle, acts as a knee flexor as well as an ankle plantar flexor. Although simultaneous motion of the knee and ankle joints is required for many activities including standing, running, swimming, and cycling, the change in ankle motion during gait has not been described in patients with cerebral palsy who underwent distal hamstring lengthening or distal hamstring lengthening with rectus femoris transfer. Therefore, we aimed to evaluate the influence of surgery involving tendons around the knee on ankle motion during gait in cerebral palsy patients. Methods: The analysis included data regarding 55 limbs from 34 patients with spastic cerebral palsy, who were followed-up after they had undergone distal hamstring lengthening with or without additional rectus femoris transfer. Mean age of the patients at time of the knee surgery was 11.2 ± 4.7 years. Preoperative and postoperative kinematic variables that were extracted from three-dimensional gait analyses were compared to assess the change in ankle motion after surgery involving tendons around the knee. The postoperative 3D gait analysis was performed at a mean of 0.9 ± 1.3 years after the surgery. The outcome measures were relevant kinematics parameters including peak ankle dorsiflexion at initial contact, peak ankle dorsiflexion during stance, ankle peak dorsiflexion during swing, and dynamic range of motion of the ankle. A linear mixed model was constructed to estimate the changes in ankle motion after adjusting for multiple factors. Results: We estimated that peak ankle dorsiflexion at initial contact, peak ankle dorsiflexion during stance, ankle peak dorsiflexion during swing, and dynamic range of motion of the ankle decreased, respectively, by 0.4º (p=0.016), 0.6º (p<0.001), 0.2º (p=0.038), and 0.5º (p=0.006) per degree increase in total range of motion of the knee after knee surgery (Table). Estimated ankle peak dorsiflexion in the swing phase increased by 0.4º per degree increased in postoperative peak knee flexion in the swing phase (Table). Age at the time of the knee surgery did not significantly affect ankle kinematics. Conclusion: Improvement in total knee range of motion was correlated with a decrease in ankle kinematics after surgery involving tendons around the knee. Knee surgery may reduce the need for an additional surgical procedure involving the ankle joint. Because the simultaneous motion of the knee and ankle joints is cross-linked, surgeons should be aware of potential changes in the ankle joint after knee surgery.
30
Bartolomei, Jonathan, Mark W. Bowers, and Kenneth J. Hunt. "Kinematics after Syndesmotic Injury: Assessing the Magnitude of Talus and Fibula Rotation and Displacement." Foot & Ankle Orthopaedics 5, no. 4 (October 1, 2020): 2473011420S0011. http://dx.doi.org/10.1177/2473011420s00114.
Full textAbstract:
Category: Ankle; Sports; Other Introduction/Purpose: High ankle sprains, or injuries to the distal tibiofibular syndesmosis, are predictive of long-term ankle dysfunction. Our objectives were to evaluate ankle mortise stability, radiographically, and kinematically, using a cadaveric model with a simulated syndesmotic injury. We also measured the ability of a suture-button system to restore natural joint motion. Methods: Eight cadaveric specimens underwent serial sectioning of the anterior-inferior tibiofibular (AITFL), interosseous (IOL), posterior-inferior tibiofibular (PITFL), and deltoid ligaments. Specimens underwent external rotation and lateral translation testing after ligament release to obtain kinematic data (using a validated infrared LED motion capture system) and radiographic measurements. We then repeated external rotation and lateral translation testing after implementing a suture-button system. Repeated measures ANOVA with a Bonferroni/Dunn post-hoc test calculated the interspecimen comparisons. Results: Sectioning of each ligament, beginning with the AITFL, significantly increased talar external rotation. After releasing the AITFL and IOL, fibular external rotation increased significantly. Posterior displacement of the fibula began following the release of AITFL. Significant radiographic widening of the medial clear space and the syndesmosis occurred only after the release of the deltoid ligament. Syndesmotic and medial clear space widening was not significantly different from the intact state under lateral translation until after the release of the deltoid ligament. Placement of the suture-button system successfully reduced the medial clear space but was unable to restore the native stability of the ankle joint. Conclusion: This project addresses rotational and kinematic changes in the ankle after syndesmotic injury by quantifying the effect of ligamentous disruption on the tibiotalar articulation. The change in joint kinematics may explain why patients with moderate-to-severe syndesmosis injuries take longer to heal and develop long-term dysfunction. Significant talar rotation and posterior fibular displacement occur during external rotation, even with moderate syndesmosis injury, and before the disruption of the deltoid ligament. Stress radiography does not appear to be a reliable indicator of mild or moderate syndesmosis injuries.
31
Gabrielli, Alexandra S., Alexandra Maxim, Tom Gale, Clarissa LeVasseur, MaCalus Hogan, and William Anderst. "Bilateral Symmetry and Sex Differences in Ankle Kinematics During the Stance Phase of Gait." Foot & Ankle Orthopaedics 4, no. 4 (October 1, 2019): 2473011419S0017. http://dx.doi.org/10.1177/2473011419s00179.
Full textAbstract:
Category: Ankle, Hindfoot Introduction/Purpose: Restoration of bilateral symmetry is used clinically to evaluate surgical and conservative treatment outcomes. However, the degree of symmetry and differences between sexes in ankle kinematics in healthy individuals remain unknown. Because relative motion between the tibia, talus and calcaneus cannot be accurately measured using conventional skin- mounted motion capture systems, biplane radiography is emerging as the preferred technique to measure in vivo ankle kinematics during functional activities. Therefore, the aims of the present study were to use biplane radiography to determine the degree of bilateral symmetry in ankle kinematics in healthy individuals and to identify sex-dependent differences in kinematics during the support phase of gait. It was hypothesized that rotational ankle range of motion (ROM) during gait is not different between males and females. Methods: Twenty healthy individuals (10 male, 10 female, age 30.7 ± 6.3years) with no history of ankle injury provided consent to participate in this IRB-approved study. Each participant walked through a biplane radiography system 6 times at a self-selected pace (1.3±0.2 m/s). Synchronized radiographs of the ankle were collected at 100 images/second for 3 trials of each ankle (90 kV, 125 mA, 1 ms exposure/image). Motion of the tibia, talus and calcaneus was tracked using a validated model-based tracking process that matches 3D bone models to the radiographs. Anatomic coordinate systems were created and used to calculate ankle kinematics. All kinematics were converted to percent stance phase and averaged over all trials for each ankle. Bilateral symmetry was determined by calculating the average absolute difference between right and left ankle joint kinematics over the full support phase of gait. Differences between male and female rotational ROM were identified using unpaired t-tests. Results: The average absolute side-to-side difference in tibio-talar joint rotations was 3.3° or less, while the average absolute side-to-side difference in subtalar joint rotations was 3.0° or less (Table 1A). For males and females, at the tibio-talar joint, the largest ROM was plantar-dorsiflexion, followed by internal/external rotation and then inversion/eversion (Table 1B). At the subalar joint, the largest ROM was inversion/eversion, with similar amounts of dorsiflexion/plantarflexion and internal/external rotation, on the order of 2° to 3°. Males demonstrated significantly less ROM in subtalar dorsiflexion/plantarflexion and tibio-talar internal/external rotation (Table 1B). Conclusion: The average side-to-side differences in healthy ankle ROM during gait are small, suggesting that the contralateral ankle may serve as a reference standard to assess kinematic outcomes after conservative or surgical treatments. The difference between male and female subtalar ROM (0.6°) may be too small to be functionally significant, however, sex differences in tibio- talar ROM appear large enough to merit consideration when assessing functional outcomes and designing ankle joint replacements. The results are limited to over-ground gait performed by relatively young and healthy adults and may not be applicable to other activities or older adults.
32
Xhevahir, Bajrami, Shala Ahmet, Hoxha Gezim, and Likaj Rame. "Dynamic Modelling and Analyzing of a Walking of Humanoid Robot." Strojnícky casopis – Journal of Mechanical Engineering 68, no. 3 (November 1, 2018): 59–76. http://dx.doi.org/10.2478/scjme-2018-0027.
Full textAbstract:
AbstractThis paper focuses on the walking improvement of a biped robot. The zero-moment point (ZMP) method is used to stabilise the walking process of robot. The kinematic model of the humanoid robot is based on Denavit- Hartenberg’s (D-H) method, as presented in this paper. This work deals with the stability analysis of a two-legged robot during double and single foot walking. It seems more difficult to analyse the dynamic behaviour of a walking robot due to its mathematical complexity. In this context most humanoid robots are based on the control model. This method needs to design not only a model of the robot itself but also the surrounding environment. In this paper, a kinematic simulation of the robotic system is performed in MATLAB. Driving torque of the left and right ankle is calculated based on the trajectory of joint angle, the same as angular velocity and angular acceleration. During this process an elmo motion controller is used for all joints. The validity of the dynamic model is tested by comparing obtained results with the simulation results.
33
MICHELSON, JAMES D., ANDREW J. HAMEL, FRANK L. BUCZEK, and NEIL A. SHARKEY. "KINEMATIC BEHAVIOR OF THE ANKLE FOLLOWING MALLEOLAR FRACTURE REPAIR IN A HIGH-FIDELITY CADAVER MODEL." Journal of Bone and Joint Surgery-American Volume 84, no. 11 (November 2002): 2029–38. http://dx.doi.org/10.2106/00004623-200211000-00019.
Full text
34
Kurpiers, Nicolas, Paul McAlpine, and Uwe G. Kersting. "A biomechanical field testing approach in snow sports: Case studies toward a detailed analysis of joint loading." Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology 234, no. 4 (June 16, 2020): 337–46. http://dx.doi.org/10.1177/1754337120918037.
Full textAbstract:
In this study, kinematic and kinetic measurements were combined to assess the effects of removing the stiff shaft from a ski boot. It was hypothesized that joint flexion at the ankle, knee and hip increase and reduce joint loading specifically at the knee. A previously developed force sensor was combined with a high-speed camera system for data collection of 6 degrees of freedom ground reaction forces and three-dimensional marker data in the field on a wave slope. The collected data were used as input to a musculoskeletal model for the estimation of joint kinematics and joint moments and contact forces in the ankle and knee. The force sensor, which was previously used for skiing, had experienced wear and tear and was thus prone to breakage. As a result, joint loading could only be analyzed for two skiers. These two skiers did not use the added range of ankle flexion to its full extent, but showed substantial reductions in joint moments and joint contact forces (e.g. knee compression force from 85 to 57 N/kg). Only one of the five experienced skiers tested was able to adopt the anticipated movement pattern by substantially increased maximum ankle joint flexion angle (from 10° to 37°) and knee joint flexion angle (from 93° to 105°) and the respective ranges of motion when skiing through a wave course. The study provides information on possible individual adaptations to ski boot modifications. The mechanical construction of the force sensor will need to be modified to withstand the high forces expected during freestyle skiing. The study also supports the future use of this measurement setup for comprehensive studies in snow sports, provided that a sufficient training period is given.
35
Austin, Gary P., Gladys E. Garrett, and David Tiberio. "Effect of Added Mass on Human Unipedal Hopping." Perceptual and Motor Skills 94, no. 3 (June 2002): 834–40. http://dx.doi.org/10.2466/pms.2002.94.3.834.
Full textAbstract:
Although hopping is considered a children's activity, it can be used to provide insight into the neuromuscular and biomechanical performance of adults. This study investigated whether mass added during unipedal hopping altered the vertical stiffness, hopping period, and angular kinematics of the lower extremity of adults. Measures of two-dimensional kinematics and vertical force were made from 10 healthy men during hopping at a preferred period under three conditions: Body Mass, Body Mass + 10%, and Body Mass + 20%. Adding mass significantly increased hopping period and hip flexion without significantly affecting vertical stiffness, ankle dorsiflexion, or knee flexion. Overall, the findings agreed with predictions based on a simple-mass spring model. The results indicate unique kinetic and kinematic responses to increased mass during hopping may have potential application in neuromuscular assessment and training for the lower extremities.
36
Fatone, Stefania, and Andrew H. Hansen. "A Model to Predict the Effect of Ankle Joint Misalignment on Calf Band Movement in Ankle-Foot Orthoses." Prosthetics and Orthotics International 31, no. 1 (March 2007): 76–87. http://dx.doi.org/10.1080/03093640600983873.
Full textAbstract:
Accurate alignment of anatomical and mechanical joint axes is one of the major biomechanical principles pertaining to articulated orthoses, yet knowledge of the potential effects of axis misalignment is limited. The purpose of this project was to model the effects of systematic linear (proximal-distal and anterior-posterior) misalignments of single axis mechanical ankle joints in an ankle-foot orthosis (AFO) in order to determine the degree and direction of calf band travel that would occur over a functional range of motion. Sagittal plane misalignments of the ankle joint centres of an AFO were simulated using a simple two-dimensional model for both a range of ankle angles and a typical able-bodied ankle kinematic curve for self-selected normal walking speed. The model assumed that no movement occurred between the foot and the foot-plate of the AFO. The model predicted that for anterior (positive horizontal) misalignments, dorsiflexion movements would cause the calf band to travel proximally (i.e., up the leg) and plantar flexion movements would cause the calf band to travel distally (i.e., down the leg). The opposite was predicted for posterior (negative horizontal) misalignments. Proximal (positive vertical) misalignments would cause only distal movements of the calf band while distal (negative vertical) misalignments would cause only proximal movements of the calf band. Anterior-posterior misalignments were found to have a much larger effect on the amount of calf band travel than proximal-distal misalignments.
37
Nazareth, Alexander, Nicole M. Mueske, and Tishya A. L. Wren. "Effect of Tibia Marker Placement on Kinematics in Pathological Gait." Journal of Applied Biomechanics 32, no. 6 (December 2016): 603–7. http://dx.doi.org/10.1123/jab.2015-0219.
Full textAbstract:
This study aimed to determine the effect of tibia marker placement on walking kinematics in children with pathological gait. Three-dimensional lower extremity gait data were collected using both a traditional tibia wand (protruding laterally from the distal shank) and a tibia crest marker on 25 children with pathological gait. Kinematic variables during walking and quiet standing were calculated using each marker and the “Plug-in Gait” implementation of the conventional gait model. For walking, average differences in kinematics between tibia markers ranged from 0.1° to 1.9° at the knee and ankle, except in the transverse plane where differences were 6.0° to 7.2°. No significant differences were found during quiet standing, indicating that differences in kinematics derive primarily from dynamic sources, which likely affect the tibia wand more than the tibia crest marker. These results suggest that the tibia crest marker can be used in place of the traditional tibia wand in clinical gait analysis.
38
Chumacero-Polanco, Erik, and James Yang. "Validation of an ankle-hip model of balance on a balance board via kinematic frequency-content." Gait & Posture 82 (October 2020): 313–21. http://dx.doi.org/10.1016/j.gaitpost.2020.09.019.
Full text
39
Mager, Fabian, Jim Richards, Malika Hennies, Eugen Dötzel, Ambreen Chohan, Alex Mbuli, and Felix Capanni. "Determination of Ankle and Metatarsophalangeal Stiffness During Walking and Jogging." Journal of Applied Biomechanics 34, no. 6 (December 1, 2018): 448–53. http://dx.doi.org/10.1123/jab.2017-0265.
Full textAbstract:
Forefoot stiffness has been shown to influence joint biomechanics. However, little or no data exist on metatarsophalangeal stiffness. Twenty-four healthy rearfoot strike runners were recruited from a staff and student population at the University of Central Lancashire. Five repetitions of shod, self-selected speed level walking, and jogging were performed. Kinetic and kinematic data were collected using retroreflective markers placed on the lower limb and foot to create a 3-segment foot model using the calibrated anatomical system technique. Ankle and metatarsophalangeal moments and angles were calculated. Stiffness values were calculated using a linear best fit line of moment versus of angle plots. Paired t tests were used to compare values between walking and jogging conditions. Significant differences were seen in ankle range of motion, but not in metatarsophalangeal range of motion. Maximum moments were significantly greater in the ankle during jogging, but these were not significantly different at the metatarsophalangeal joint. Average ankle joint stiffness exhibited significantly lower stiffness when walking compared with jogging. However, the metatarsophalangeal joint exhibited significantly greater stiffness when walking compared with jogging. A greater understanding of forefoot stiffness may inform the development of footwear, prosthetic feet, and orthotic devices, such as ankle foot orthoses for walking and sporting activities.
40
Son, K., J. A. A. Miller, and A. B. Schultz. "The Mechanical Role of the Trunk and Lower Extremities in a Seated Weight-Moving Task in the Sagittal Plane." Journal of Biomechanical Engineering 110, no. 2 (May 1, 1988): 97–103. http://dx.doi.org/10.1115/1.3108424.
Full textAbstract:
A two-dimensional, sagittally-symmetric biomechanical model was developed to analyze the joint moments required to stabilize the trunk in a seated, dynamic, weight-moving task. Kinematic and reaction force data were measured while subjects moved a hand-held weight (0–4 kgf) at shoulder level to and fro at 1 Hz. These data were then used for model input and validation purposes. A second, simpler model was used to simulate how joint loads varied with weight held, trunk inclination, and movement frequency. The results for this seated task demonstrate a) significant trunk, hip, knee, and ankle joint moments (37, 13, 4, 13 percent of maximum strength values, respectively) were required, b) considerable intersubject differences in mean joint moments (more than 66 percent) were found, which primarily were due to subtle differences in body segment kinematics and lower extremities use, and c) the important role of the lower extremities in stabilizing the trunk in the seated posture.
41
Souza, Thales R., Haroldo L. Fonseca, Ana Carolina A. Vaz, Juliana S. Antero, Cristiano S. Marinho, and Sérgio T. Fonseca. "Between-Day Reliability of a Cluster-Based Method for Multisegment Kinematic Analysis of the Foot-Ankle Complex." Journal of the American Podiatric Medical Association 104, no. 6 (November 1, 2014): 601–9. http://dx.doi.org/10.7547/8750-7315-104.6.601.
Full textAbstract:
Background Detailed description of foot pronation-supination requires multisegment evaluation of the kinematics of the foot-ankle complex. There are noninvasive methods with independent (single) tracking markers attached directly to the skin. However, these methods are inconsistent with the usual rigid segments assumption. In contrast, using clustered markers is compatible with this assumption and is necessary for analyses that need tracking markers to be distant from the foot (eg, shod walking). This study investigated the between-day reliability of a cluster-based method for multisegment analysis of foot-ankle angles related to pronation-supination. Methods Ten healthy adults participated in the study. An anatomically based, three-dimensional model comprising the shank, calcaneus, and forefoot was created. Rigid clusters of tracking markers were used to determine the relative positions and motions of the segments. Mean positions were measured with the subtalar joint in neutral position during standing. Furthermore, mean angles, peaks, and timings of peaks were measured during the stance phase of walking. All of the variables were measured twice, with a 1-week interval. To evaluate reliability, intraclass correlation coefficients were calculated for discrete variables and coefficients of multiple correlation for entire gait curves. Results Intraclass correlation coefficients varied from 0.8 to 0.93 for the angles obtained when the subtalar joint was in neutral and from 0.76 to 0.9 for walking variables. Coefficients of multiple correlation varied from 0.93 to 0.97 for walking curves. Conclusions The method described has good to high reliability and provides a systematic method for multisegment kinematic evaluation of foot-ankle pronation-supination.
42
Holm, Jonathan K., Jonas Contakos, Sang-Wook Lee, and John Jang. "Energetics and Passive Dynamics of the Ankle in Downhill Walking." Journal of Applied Biomechanics 26, no. 4 (November 2010): 379–89. http://dx.doi.org/10.1123/jab.26.4.379.
Full textAbstract:
This study investigated the energetics of the human ankle during the stance phase of downhill walking with the goal of modeling ankle behavior with a passive spring and damper mechanism. Kinematic and kinetic data were collected on eight male participants while walking down a ramp with inclination varying from 0° to 8°. The ankle joint moment in the sagittal plane was calculated using inverse dynamics. Mechanical energy injected or dissipated at the ankle joint was computed by integrating the power across the duration of the stance phase. The net mechanical energy of the ankle was approximately zero for level walking and monotonically decreased (i.e., became increasingly negative) during downhill walking as the slope decreased. The indication is that the behavior of the ankle is energetically passive during downhill walking, playing a key role in dissipating energy from one step to the next. A passive mechanical model consisting of a pin joint coupled with a revolute spring and damper was fit to the ankle torque and its parameters were estimated for each downhill slope using linear regression. The passive model demonstrated good agreement with actual ankle dynamics as indicated by low root-mean-square error values. These results indicate the stance phase behavior of the human ankle during downhill walking may be effectively duplicated by a passive mechanism with appropriately selected spring and damping characteristics.
43
Wei, Feng, Jerrod E. Braman, Brian T. Weaver, and Roger C. Haut. "Determination of dynamic ankle ligament strains from a computational model driven by motion analysis based kinematic data." Journal of Biomechanics 44, no. 15 (October 2011): 2636–41. http://dx.doi.org/10.1016/j.jbiomech.2011.08.010.
Full text
44
Kianifar, Rezvan, Vladimir Joukov, Alexander Lee, Sachin Raina, and Dana Kulić. "Inertial measurement unit-based pose estimation: Analyzing and reducing sensitivity to sensor placement and body measures." Journal of Rehabilitation and Assistive Technologies Engineering 6 (January 2019): 205566831881345. http://dx.doi.org/10.1177/2055668318813455.
Full textAbstract:
Introduction Inertial measurement units have been proposed for automated pose estimation and exercise monitoring in clinical settings. However, many existing methods assume an extensive calibration procedure, which may not be realizable in clinical practice. In this study, an inertial measurement unit-based pose estimation method using extended Kalman filter and kinematic chain modeling is adapted for lower body pose estimation during clinical mobility tests such as the single leg squat, and the sensitivity to parameter calibration is investigated. Methods The sensitivity of pose estimation accuracy to each of the kinematic model and sensor placement parameters was analyzed. Sensitivity analysis results suggested that accurate extraction of inertial measurement unit orientation on the body is a key factor in improving the accuracy. Hence, a simple calibration protocol was proposed to reach a better approximation for inertial measurement unit orientation. Results After applying the protocol, the ankle, knee, and hip joint angle errors improved to [Formula: see text], and [Formula: see text], without the need for any other calibration. Conclusions Only a small subset of kinematic and sensor parameters contribute significantly to pose estimation accuracy when using body worn inertial sensors. A simple calibration procedure identifying the inertial measurement unit orientation on the body can provide good pose estimation performance.
45
Kim, Seyoung, Fay B. Horak, Patricia Carlson-Kuhta, and Sukyung Park. "Postural Feedback Scaling Deficits in Parkinson's Disease." Journal of Neurophysiology 102, no. 5 (November 2009): 2910–20. http://dx.doi.org/10.1152/jn.00206.2009.
Full textAbstract:
Many differences in postural responses have been associated with age and Parkinson's disease (PD), but until now there has been no quantitative model to explain these differences. We developed a feedback control model of body dynamics that could reproduce the postural responses of young subjects, elderly subjects, and subjects with PD, and we investigated whether the postural impairments of subjects with PD can be described as an abnormal scaling of postural feedback gain. Feedback gains quantify how the nervous system generates compensatory joint torques based on kinematic responses. Seven subjects in each group experienced forward postural perturbations to seven different backward support surface translations ranging from 3- to 15-cm amplitudes and with a constant duration of 275 ms. Ground reaction forces and joint kinematics were measured to obtain joint torques from inverse dynamics. A full-state feedback controller with a two-segment body dynamic model was used to simulate joint kinematics and kinetics in response to perturbations. Results showed that all three subject groups gradually scaled postural feedback gains as a function of perturbation amplitudes, and the scaling started even before the maximum allowable ankle torque was reached. This result implies that the nervous system takes body dynamics into account and adjusts postural feedback gains to accommodate biomechanical constraints. PD subjects showed significantly smaller than normal ankle feedback gain with low scaling and larger hip feedback gain, which led to an early violation of the flat-foot constraint and unusually small (bradykinetic) postural responses. Our postural feedback control model quantitatively described the postural abnormality of the patients with PD as abnormal feedback gains and reduced ability to modify postural feedback gain with changes in postural challenge.
46
Yatsun, S. F., Khalil Hamed Mohammed Hamood Al Manji, A. A. Postolny, and A. S. Yatsun. "Modeling Gait Patterns of a Patient with Orthopedic Injury Using an Exoskeleton." Proceedings of the Southwest State University 23, no. 6 (February 23, 2020): 176–88. http://dx.doi.org/10.21869/2223-1560-2019-23-6-176-188.
Full textAbstract:
Purpose of reseach. The paper describes the EXOLITE-REHAB rehabilitation robotic complex which makes it possible to do rehabilitation exercises of lower limbs of patients by performing leg lifting, verticalization, squats and other types of movement. In many countries, research work is underway to create devices that allow a person to move in space when the musculo-skeletal system is damaged. Therefore, the purpose of this article is to study and set the basic regularities and algorithms based on mathematical models describing the controlled movement of the lower limbs exoskeleton by the example of modeling the movement of the exoskeleton's ankle joint.Methods. The key feature of the complex is the use of a follower-up control system that allows us to provide a prescribed movement of the human ankle joint with a high degree of accuracy in a wide range of parameters’ changes. Methods of mathematical modeling of the ankle joint movement are applied, taking into account their subsequent possible use in modeling the movement of exoskeleton links.Results. A kinematic setting of the ankle joint movement trajectory is used in order to simulate the operation of a robotic system. In order to find the vector of generalized coordinates, the inverse kinematics problem is solved using the vector-matrix method with the application of Jacobian matrix. The results of numerical simulation show high convergence and adequacy of the proposed method.Conclusion. The article considers the method of using a follower-up control system that has a sufficient degree of accuracy of copying the trajectory. The results of modeling the follower-up control system of the EXOLITE-REHAB rehabilitation exoskeleton, working according to the developed algorithm, show that it is able to repeat the required trajectory with sufficient accuracy. In the future, we plan to study the system more deeply on a three-dimensional model with electric drives.
47
Rakshit, Ritwik, Yujiang Xiang, and James Yang. "Dynamic-joint-strength-based two-dimensional symmetric maximum weight-lifting simulation: Model development and validation." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 234, no. 7 (April 8, 2020): 660–73. http://dx.doi.org/10.1177/0954411920913374.
Full textAbstract:
This article presents an optimization formulation and experimental validation of a dynamic-joint-strength-based two-dimensional symmetric maximum weight-lifting simulation. Dynamic joint strength (the net moment capacity as a function of joint angle and angular velocity), as presented in the literature, is adopted in the optimization formulation to predict the symmetric maximum lifting weight and corresponding motion. Nineteen participants were recruited to perform a maximum-weight-box-lifting task in the laboratory, and kinetic and kinematic data including motion and ground reaction forces were collected using a motion capture system and force plates, respectively. For each individual, the predicted spine, shoulder, elbow, hip, knee, and ankle joint angles, as well as vertical and horizontal ground reaction force and box weight, were compared with the experimental data. Both root-mean-square error and Pearson’s correlation coefficient ( r) were used for the validation. The results show that the proposed two-dimensional optimization-based motion prediction formulation is able to accurately predict all joint angles, box weights, and vertical ground reaction forces, but not horizontal ground reaction forces.
48
Klous, Miriam, Erich Müller, and Hermann Schwameder. "Three-Dimensional Lower Extremity Joint Loading in a Carved Ski and Snowboard Turn: A Pilot Study." Computational and Mathematical Methods in Medicine 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/340272.
Full textAbstract:
A large number of injuries to the lower extremity occur in skiing and snowboarding. Due to the difficulty of collecting 3D kinematic and kinetic data with high accuracy, a possible relationship between injury statistic and joint loading has not been studied. Therefore, the purpose of the current study was to compare ankle and knee joint loading at the steering leg between carved ski and snowboard turns. Kinetic data were collected using mobile force plates mounted under the toe and heel part of the binding on skies or snowboard (KISTLER). Kinematic data were collected with five synchronized, panning, tilting, and zooming cameras. An extended version of the Yeadon model was applied to calculate inertial properties of the segments. Ankle and knee joint forces and moments were calculated using inverse dynamic analysis. Results showed higher forces along the longitudinal axis in skiing and similar forces for skiing and snowboarding in anterior-posterior and mediolateral direction. Joint moments were consistently greater during a snowboard turn, but more fluctuations were observed in skiing. Hence, when comparing joint loading between carved ski and snowboard turns, one should differentiate between forces and moments, including the direction of forces and moments and the turn phase.
49
Luczak, Tony, David Saucier, Reuben Burch V., John Ball, Harish Chander, Adam Knight, Pan Wei, and Tashfin Iftekhar. "Closing the Wearable Gap: Mobile Systems for Kinematic Signal Monitoring of the Foot and Ankle." Electronics 7, no. 7 (July 18, 2018): 117. http://dx.doi.org/10.3390/electronics7070117.
Full textAbstract:
Interviews from strength and conditioning coaches across all levels of athletic competition identified their two biggest concerns with the current state of wearable technology: (a) the lack of solutions that accurately capture data “from the ground up” and (b) the lack of trust due to inconsistent measurements. The purpose of this research is to investigate the use of liquid metal sensors, specifically Liquid Wire sensors, as a potential solution for accurately capturing ankle complex movements such as plantar flexion, dorsiflexion, inversion, and eversion. Sensor stretch linearity was validated using a Micro-Ohm Meter and a Wheatstone bridge circuit. Sensors made from different substrates were also tested and discovered to be linear at multiple temperatures. An ankle complex model and computing unit for measuring resistance values were developed to determine sensor output based on simulated plantar flexion movement. The sensors were found to have a significant relationship between the positional change and the resistance values for plantar flexion movement. The results of the study ultimately confirm the researchers’ hypothesis that liquid metal sensors, and Liquid Wire sensors specifically, can serve as a mitigating substitute for inertial measurement unit (IMU) based solutions that attempt to capture specific joint angles and movements.
50
Zhang, Leiyu, Jianfeng Li, Mingjie Dong, Bin Fang, Ying Cui, Shiping Zuo, and Kai Zhang. "Design and Workspace Analysis of a Parallel Ankle Rehabilitation Robot (PARR)." Journal of Healthcare Engineering 2019 (March 14, 2019): 1–10. http://dx.doi.org/10.1155/2019/4164790.
Full textAbstract:
The ankle rehabilitation robot is essential equipment for patients with foot drop and talipes valgus to make up deficiencies of the manual rehabilitation training and reduce the workload of rehabilitation physicians. A parallel ankle rehabilitation robot (PARR) was developed which had three rotational degrees of freedom around a virtual stationary center for the ankle joint. The center of the ankle should be coincided with the virtual stationary center during the rehabilitation process. Meanwhile, a complete information acquisition system was constructed to improve the human-machine interactivity among the robot, patients, and physicians. The physiological motion space (PMS) of ankle joint in the autonomous and boundary elliptical movements was obtained with the help of the RRR branch and absolute encoders. The natural extreme postures of the ankle complex are the superposition of the three typical movements at the boundary motions. Based on the kinematic model of PARR, the theoretical workspace (TWS) of the parallel mechanism was acquired using the limit boundary searching method and could encircle PMS completely. However, the effective workspace (EWS) was smaller than TWS due to the physical structure, volume, and interference of mechanical elements. In addition, EWS has more clinical significance for the ankle rehabilitation. The PARR prototype satisfies all single-axis rehabilitations of the ankle and can cover most compound motions of the ankle. The goodness of fit of PMS can reach 93.5%. Hence, the developed PARR can be applied to the ankle rehabilitation widely.