To see the other types of publications on this topic, follow the link: Axial Kinematics.
Journal articles on the topic 'Axial Kinematics'
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 'Axial Kinematics.'
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
Feng, Y., and L. Boersma. "Kinematics of axial plant root growth." Journal of Theoretical Biology 174, no. 1 (May 1995): 109–17. http://dx.doi.org/10.1006/jtbi.1995.0083.
Full text
2
Kuz'min, A. O., V. V. Popov, and S. M. Stazhkov. "Hydrodynamic processes in the piston and cylinder unit of axial-piston hydraulic machines." Journal of «Almaz – Antey» Air and Space Defence Corporation, no. 4 (December 30, 2017): 86–90. http://dx.doi.org/10.38013/2542-0542-2017-4-86-90.
Full textAbstract:
The purpose of the research was to analyze the kinematics of the piston mechanism of an axial-piston hydraulic machine with an adjustable-angle cam plate. The kinematic analysis resulted in establishing various types of relative motion of the piston in the guide bushing, writing and solving Reynolds equation with respect to velocities. A sweep method was used to construct a pressure field in the working fluid layer between the piston and the guide bushing. Pressure fields are constructed for several cases of kinematics of the piston mechanism.
3
Bajcar, Tom, Brane Širok, and Ferdinand Trenc. "Flow kinematics in a rotating axial diffuser." Experimental Thermal and Fluid Science 27, no. 7 (September 2003): 769–80. http://dx.doi.org/10.1016/s0894-1777(02)00314-x.
Full text
4
Michelson, James D., and Stephen L. Helgemo. "Kinematics of the Axially Loaded Ankle." Foot & Ankle International 16, no. 9 (September 1995): 577–82. http://dx.doi.org/10.1177/107110079501600912.
Full textAbstract:
An apparatus that allowed the application of a 900 N axial load and the simultaneous measurement of rotation in the sagittal, coronal, and axial planes was used to study the normal kinematics of the ankle in 13 below-knee amputation specimens. Two testing routines were done on all specimens. In the first sequence, specimens were moved through a dorsiflexion (DF) and plantarflexion (PF) arc of 60° (25° DF and 35° PF). DF was associated with an average of 2.5° of external rotation, and PF was associated with an average of <1° of internal rotation. In the coronal plane, PF and DF were both associated with <1° of varus. In the second part of the testing, the ankle position in the sagittal plane (DF/PF) was fixed and the axial load was increased from 50 N to 750 N in 100-N intervals. Increasing the axial load caused an increase in external rotation and valgus of 1° to 2°. For axial rotation, external rotation was more pronounced in PF than DF. The effect of load on the increase on valgus was not affected by sagittal ankle position. The effect of increasing axial load on sagittal rotation was to increase DF or PF <2° over the entire range of loads and sagittal positions. The understanding of ankle biomechanics is essential to the formulation of rational guidelines for the treatment of ankle pathology and the prediction of the long-term consequences of ankle injuries. The incomplete understanding of this subject is evident when the disparate recommendations for a number of common conditions are considered. By examining the three-dimensional motion of the stable ankle, a more precise understanding of the abnormal three-dimensional motions associated with instability can be achieved. This knowledge will permit a logical approach to treatment of ankle fractures.
5
Pelz, Peter, Paul Taubert, and Ferdinand-J. Cloos. "Vortex Structure and Kinematics of Encased Axial Turbomachines." International Journal of Turbomachinery, Propulsion and Power 3, no. 2 (April 27, 2018): 11. http://dx.doi.org/10.3390/ijtpp3020011.
Full text
6
Gillis, G. "Anguilliform locomotion in an elongate salamander (Siren intermedia): effects of speed on axial undulatory movements." Journal of Experimental Biology 200, no. 4 (February 1, 1997): 767–84. http://dx.doi.org/10.1242/jeb.200.4.767.
Full textAbstract:
Many workers interested in the mechanics and kinematics of undulatory aquatic locomotion have examined swimming in fishes that use a carangiform or subcarangiform mode. Few empirical data exist describing and quantifying the movements of elongate animals using an anguilliform mode of swimming. Using high-speed video, I examine the axial undulatory kinematics of an elongate salamander, Siren intermedia, in order to provide data on how patterns of movement during swimming vary with body position and swimming speed. In addition, swimming kinematics are compared with those of other elongate vertebrates to assess the similarity of undulatory movements within the anguilliform locomotor mode. In Siren, most kinematic patterns vary with longitudinal position. Tailbeat period and frequency, stride length, Froude efficiency and the lateral velocity and angle of attack of tail segments all vary significantly with swimming speed. Although swimming speed does not show a statistically significant effect on kinematic variables such as maximum undulatory amplitude (which increases non-linearly along the body), intervertebral flexion and path angle, examination of the data suggests that speed probably has subtle and site-specific effects on these variables which are not detected here owing to the small sample size. Maximum lateral displacement and flexion do not coincide in time within a given tailbeat cycle. Furthermore, the maximum orientation (angle with respect to the animal's direction of forward movement) and lateral velocity of tail segments also do not coincide in time. Comparison of undulatory movements among diverse anguilliform swimmers suggests substantial variation across taxa in parameters such as tailbeat amplitude and in the relationship between tailbeat frequency and swimming speed. This variation is probably due, in part, to external morphological differences in the shape of the trunk and tail among these taxa.
7
Fu, Jiang Feng, Hua Cong Li, Jia Li, and Shu Hong Wang. "Kinematics Modelling and Simulation of Aero-Engine Fuel Piston Pump." Applied Mechanics and Materials 680 (October 2014): 299–302. http://dx.doi.org/10.4028/www.scientific.net/amm.680.299.
Full textAbstract:
Kinematics parameters calculation is the basis of piston pump design and performance analysis. Taking an axial piston pump with incline piston and spherical swash plate as the research object, Aimed at the deficiency of current formula for calculating piston pump kinematics parameters which included displacement, velocity and acceleration. In this paper, according to piston pump part motion geometry relationship, a correction kinematics algorithm is deduced by using the the spherical coordinate and cartesian coordinate transformation method, the analyse method and deduction procedure ensure the new calculating formula are precise in theory. Applying the calculating formula to an aero engine fuel axial piston pump, results show that. The displacement, velocity, acceleration according to the kinematics principle of piston pump, it can be used in the kind of piston pump kinematics parameters calculation and current calculating method evaluation.
8
Barrance, Peter J., Glenn N. Williams, John E. Novotny, and Thomas S. Buchanan. "A Method for Measurement of Joint Kinematics in Vivo by Registration of 3-D Geometric Models With Cine Phase Contrast Magnetic Resonance Imaging Data." Journal of Biomechanical Engineering 127, no. 5 (May 31, 2005): 829–37. http://dx.doi.org/10.1115/1.1992524.
Full textAbstract:
A new method is presented for measuring joint kinematics by optimally matching modeled trajectories of geometric surface models of bones with cine phase contrast (cine-PC) magnetic resonance imaging data. The incorporation of the geometric bone models (GBMs) allows computation of kinematics based on coordinate systems placed relative to full 3-D anatomy, as well as quantification of changes in articular contact locations and relative velocities during dynamic motion. These capabilities are additional to those of cine-PC based techniques that have been used previously to measure joint kinematics during activity. Cine-PC magnitude and velocity data are collected on a fixed image plane prescribed through a repetitively moved skeletal joint. The intersection of each GBM with a simulated image plane is calculated as the model moves along a computed trajectory, and cine-PC velocity data are sampled from the regions of the velocity images within the area of this intersection. From the sampled velocity data, the instantaneous linear and angular velocities of a coordinate system fixed to the GBM are estimated, and integration of the linear and angular velocities is used to predict updated trajectories. A moving validation phantom that produces motions and velocity data similar to those observed in an experiment on human knee kinematics was designed. This phantom was used to assess cine-PC rigid body tracking performance by comparing the kinematics of the phantom measured by this method to similar measurements made using a magnetic tracking system. Average differences between the two methods were measured as 2.82 mm rms for anterior∕posterior tibial position, and 2.63 deg rms for axial rotation. An inter-trial repeatability study of human knee kinematics using the new method produced rms differences in anterior∕posterior tibial position and axial rotation of 1.44 mm and 2.35 deg. The performance of the method is concluded to be sufficient for the effective study of kinematic changes caused to knees by soft tissue injuries.
9
Cass, Joseph R., and Harry Settles. "Ankle Instability: In Vitro Kinematics in Response to Axial Load." Foot & Ankle International 15, no. 3 (March 1994): 134–40. http://dx.doi.org/10.1177/107110079401500308.
Full textAbstract:
This study was undertaken to elucidate the kinematics of hindfoot instability. An axial load was applied to the inverted hindfoot. Unlike prior studies, axial rotation was not constrained. Using computerized tomography, measurements were made on the axial views of external or internal rotation of the leg, talus, and calcaneus. On the coronal views, tilting of the talus at the ankle and subtalar joints was assessed. No tilting of the talus in the mortise occurred with isolated release of the anterior talofibular (ATF) or calcaneofibular (CF) ligament. In every specimen, talar tilt occurred only after both ligaments were released, averaging 20.6°. External rotation of the leg occurred with inversion averaging 11.1° in the intact specimen. The leg averaged a further external rotation of 4.9° after ATF release and 12.8° further than the intact inverted specimens when both ligaments (ATF-CF) had been released. In earlier reports on the subject, the articular surfaces were believed to be the main constraint against tilting of the talus. In those studies, either axial rotation was constrained while inversion was allowed, or vice versa. Based on the data reported here, the ATF and the CF work in tandem to prevent tilting of the talus, and the articular surfaces do not seem to prevent tilting of the talus in the mortise.
10
Khobkhun, Fuengfa, Mark A. Hollands, Jim Richards, and Amornpan Ajjimaporn. "Can We Accurately Measure Axial Segment Coordination during Turning Using Inertial Measurement Units (IMUs)?" Sensors 20, no. 9 (April 29, 2020): 2518. http://dx.doi.org/10.3390/s20092518.
Full textAbstract:
Camera-based 3D motion analysis systems are considered to be the gold standard for movement analysis. However, using such equipment in a clinical setting is prohibitive due to the expense and time-consuming nature of data collection and analysis. Therefore, Inertial Measurement Units (IMUs) have been suggested as an alternative to measure movement in clinical settings. One area which is both important and challenging is the assessment of turning kinematics in individuals with movement disorders. This study aimed to validate the use of IMUs in the measurement of turning kinematics in healthy adults compared to a camera-based 3D motion analysis system. Data were collected from twelve participants using a Vicon motion analysis system which were compared with data from four IMUs placed on the forehead, middle thorax, and feet in order to determine accuracy and reliability. The results demonstrated that the IMU sensors produced reliable kinematic measures and showed excellent reliability (ICCs 0.80–0.98) and no significant differences were seen in paired t-tests in all parameters when comparing the two systems. This suggests that the IMU sensors provide a viable alternative to camera-based motion capture that could be used in isolation to gather data from individuals with movement disorders in clinical settings and real-life situations.
11
Jimenez, Yordano E., Ariel L. Camp, Jonathan D. Grindall, and Elizabeth L. Brainerd. "Axial morphology and 3D neurocranial kinematics in suction-feeding fishes." Biology Open 7, no. 9 (September 15, 2018): bio036335. http://dx.doi.org/10.1242/bio.036335.
Full text
12
McElligott, Melissa B., and Donald M. O’Malley. "Prey Tracking by Larval Zebrafish: Axial Kinematics and Visual Control." Brain, Behavior and Evolution 66, no. 3 (2005): 177–96. http://dx.doi.org/10.1159/000087158.
Full text
13
Miu, Petre I., and Heinz-Dieter Kutzbach. "Mathematical model of material kinematics in an axial threshing unit." Computers and Electronics in Agriculture 58, no. 2 (September 2007): 93–99. http://dx.doi.org/10.1016/j.compag.2007.04.002.
Full text
14
De Rosario, Helios, Juan Manuel Belda-Lois, Francisco Fos, Enrique Medina, Rakel Poveda-Puente, and Michael Kroll. "Correction of Joint Angles From Kinect for Balance Exercising and Assessment." Journal of Applied Biomechanics 30, no. 2 (April 2014): 294–99. http://dx.doi.org/10.1123/jab.2013-0062.
Full textAbstract:
The new generation of videogame interfaces such as Microsoft’s Kinect opens the possibility of implementing exercise programs for physical training, and of evaluating and reducing the risks of elderly people falling. However, applications such as these might require measurements of joint kinematics that are more robust and accurate than the standard output given by the available middleware. This article presents a method based on particle filters for calculating joint angles from the positions of the anatomical points detected by PrimeSense’s NITE software. The application of this method to the measurement of lower limb kinematics reduced the error by one order of magnitude, to less than 10°, except for hip axial rotation, and it was advantageous over inverse kinematic analysis, in ensuring a robust and smooth solution without singularities, when the limbs are out-stretched and anatomical landmarks are aligned.
15
Lukashevich, U. A., U. U. Ponomarev, U. E. Mitskevich, S. V. Gubkin, Y. A. Gavrilovich, E. A. Zhurko, and A. N. Kipel. "The phenomenology of inertial kinematics in the structure of forming motor adaptations." Doklady BGUIR 18, no. 5 (September 2, 2020): 62–70. http://dx.doi.org/10.35596/1729-7648-2020-18-5-62-70.
Full textAbstract:
The aim of the study was to develop a methodology for assessing the state of motor adaptation at the level of the main joint elements of the locomotor system when performing postural deviations with inertial components in a group of healthy volunteers (n=24). To conduct the study we used the “Teslasuit” smart suit as a technology with a system of inertial measuring units. A virtual skeletal model of the subject’s body was reconstructed on the obtained quaternions for each direction of spatial displacement. Parameters of inertial kinematic were calculated by the Fast Fourier Transform in the frequency bands of 0.1–5, 6–10, and 11–15 Hz. To assess motor adaptive reactions, we developed the following tests: ventrodorsal displacement test; laterolateral displacement test; linear displacement test in vertical direction; axial rotation test around vertical. All test tasks were performed using biofeedback as a virtual reality environment. The study revealed the presence of universal motor adaptation mechanisms with activation of the components of axial rotation of the trunk and axial rotation and flexion of the leading shoulder joint. At the same time, a dynamic phase of postural regulation during axial rotations and tilts of the body leads to the activation of motor adaptation mechanisms from the leading hip, knee, and ankle joints, while axial movements form a picture of the kinematic stabilization of these locomotor system elements.
16
Rivière, Charles, Stefan Lazic, Loïc Villet, Yann Wiart, Sarah Muirhead Allwood, and Justin Cobb. "Kinematic alignment technique for total hip and knee arthroplasty." EFORT Open Reviews 3, no. 3 (March 2018): 98–105. http://dx.doi.org/10.1302/2058-5241.3.170022.
Full textAbstract:
Conventional techniques for hip and knee arthroplasty have led to good long-term clinical outcomes, but complications remain despite better surgical precision and improvements in implant design and quality. Technological improvements and a better understanding of joint kinematics have facilitated the progression to ‘personalized’ implant positioning (kinematic alignment) for total hip (THA) and knee (TKA) arthroplasty, the true value of which remains to be determined. By achieving a true knee resurfacing, the kinematic alignment (KA) technique for TKA aims at aligning the components with the physiological kinematic axes of the knee and restoring the constitutional tibio-femoral joint line frontal and axial orientation and soft-tissue laxity. The KA technique for THA aims at restoring the native ‘combined femoro-acetabular anteversion’ and the hip’s centre of rotation, and occasionally adjusting the cup position and design based on the assessment of the individual spine-hip relation. The key element for optimal prosthetic joint kinematics (hip or knee) is to reproduce the femoral anatomy. The transverse acetabular ligament (TAL) is the reference landmark to adjust the cup position. Cite this article: EFORT Open Rev 2018;3:98-105. DOI: 10.1302/2058-5241.3.170022
17
Franco, Luca, Raj Sengupta, Logan Wade, and Dario Cazzola. "A novel IMU-based clinical assessment protocol for Axial Spondyloarthritis: a protocol validation study." PeerJ 9 (January 26, 2021): e10623. http://dx.doi.org/10.7717/peerj.10623.
Full textAbstract:
Clinical assessment of spinal impairment in Axial Spondyloarthritis is currently performed using the Bath Ankylosing Spondylitis Metrological Index (BASMI). Despite being appreciated for its simplicity, the BASMI index lacks sensitivity and specificity of spinal changes, demonstrating poor association with radiographical range of motion (ROM). Inertial measurement units (IMUs) have shown promising results as a cost-effective method to quantitatively examine movement of the human body, however errors due to sensor angular drift have limited their application to a clinical space. Therefore, this article presents a wearable sensor protocol that facilitates unrestrained orientation measurements in space while limiting sensor angular drift through a novel constraint-based approach. Eleven healthy male participants performed five BASMI-inspired functional movements where spinal ROM and continuous kinematics were calculated for five spine segments and four spinal joint levels (lumbar, lower thoracic, upper thoracic and cervical). A Bland–Altman analysis was used to assess the level of agreement on range of motion measurements, whilst intraclass correlation coefficient (ICC), standardised error measurement, and minimum detectable change (MDC) to assess relative and absolute reliability. Continuous kinematics error was investigated through root mean square error (RMSE), maximum absolute error (MAE) and Spearman correlation coefficient (ρ). The overall error in the measurement of continuous kinematic measures was low in both the sagittal (RMSE = 2.1°), and frontal plane (RMSE = 2.3°). ROM limits of agreement (LoA) and minimum detectable change were excellent for the sagittal plane (maximum value LoA 1.9° and MDC 2.4°) and fair for lateral flexion (overall value LoA 4.8° and MDC 5.7°). The reliability analysis showed excellent level of agreement (ICC > 0.9) for both segment and joint ROM across all movements. The results from this study demonstrated better or equivalent accuracy than previous studies and were considered acceptable for application in a clinical setting. The protocol has shown to be a valuable tool for the assessment of spinal ROM and kinematics, but a clinical validation study on Axial Spondyloarthritis patients is required for the development and testing of a novel mobility index.
18
Moon, BR, and C. Gans. "Kinematics, muscular activity and propulsion in gopher snakes." Journal of Experimental Biology 201, no. 19 (October 1, 1998): 2669–84. http://dx.doi.org/10.1242/jeb.201.19.2669.
Full textAbstract:
Previous studies have addressed the physical principles and muscular activity patterns underlying terrestrial lateral undulation in snakes, but not the mechanism by which muscular activity produces curvature and propulsion. In this study, we used synchronized electromyography and videography to examine the muscular basis and propulsive mechanism of terrestrial lateral undulation in gopher snakes Pituophis melanoleucus affinis. Specifically, we used patch electrodes to record from the semispinalis, longissimus dorsi and iliocostalis muscles in snakes pushing against one or more pegs. Axial bends propagate posteriorly along the body and contact the pegs at or immediately posterior to an inflection of curvature, which then reverses anterior to the peg. The vertebral column bends broadly around a peg, whereas the body wall bends sharply and asymmetrically around the anterior surface of the peg. The epaxial muscles are always active contralateral to the point of contact with a peg; they are activated slightly before or at the point of maximal convexity and deactivated variably between the inflection point and the point of maximal concavity. This pattern is consistent with muscular shortening and the production of axial bends, although variability in the pattern indicates that other muscles may affect the mechanics of the epaxial muscles. The kinematic and motor patterns in snakes crawling against experimentally increased drag indicated that forces are produced largely by muscles that are active in the axial bend around each peg, rather than by distant muscles from which the forces might be transmitted by connective tissues. At each point of force exertion, the propulsive mechanism of terrestrial lateral undulation may be modeled as a type of cam-follower, in which continuous bending of the trunk around the peg produces translation of the snake.
19
Ghirardelli, Stefano, Jessica L. Asay, Erika A. Leonardi, Tommaso Amoroso, Thomas P. Andriacchi, and Pier Francesco Indelli. "Kinematic Comparison between Medially Congruent and Posterior-Stabilized Third-Generation TKA Designs." Journal of Functional Morphology and Kinesiology 6, no. 1 (March 15, 2021): 27. http://dx.doi.org/10.3390/jfmk6010027.
Full textAbstract:
Background: This study compares knee kinematics in two groups of patients who have undergone primary total knee arthroplasty (TKA) using two different modern designs: medially congruent (MC) and posterior-stabilized (PS). The aim of the study is to demonstrate only minimal differences between the groups. Methods: Ten TKA patients (4 PS, 6 MC) with successful clinical outcomes were evaluated through 3D knee kinematics analysis performed using a multicamera optoelectronic system and a force platform. Extracted kinematic data included knee flexion angle at heel-strike (KFH), peak midstance knee flexion angle (MSKFA), maximum and minimum knee adduction angle (KAA), and knee rotational angle at heel-strike. Data were compared with a group of healthy controls. Results: There were no differences in preferred walking speed between MC and PS groups, but we found consistent differences in knee function. At heel-strike, the knee tended to be more flexed in the PS group compared to the MC group; the MSKFA tended to be higher in the PS group compared to the MC group. There was a significant fluctuation in KAA during the swing phase in the PS group compared to the MC group, PS patients showed a higher peak knee flexion moment compared to MC patients, and the PS group had significantly less peak internal rotation moments than the MC group. Conclusions: Modern, third-generation TKA designs failed to reproduce normal knee kinematics. MC knees tended to reproduce a more natural kinematic pattern at heel-strike and during axial rotation, while PS knees showed better kinematics during mid-flexion.
20
Long, J., M. Mchenry, and N. Boetticher. "UNDULATORY SWIMMING: HOW TRAVELING WAVES ARE PRODUCED AND MODULATED IN SUNFISH (LEPOMIS GIBBOSUS)." Journal of Experimental Biology 192, no. 1 (July 1, 1994): 129–45. http://dx.doi.org/10.1242/jeb.192.1.129.
Full textAbstract:
We have developed an experimental procedure in which the in situ locomotor muscles of dead fishes can be electrically stimulated to generate swimming motions. This procedure gives the experimenter control of muscle activation and the mechanical properties of the body. Using pumpkinseed sunfish, Lepomis gibbosus, we investigated the mechanics of undulatory swimming by comparing the swimming kinematics of live sunfish with the kinematics of dead sunfish made to swim using electrical stimulation. In electrically stimulated sunfish, undulatory waves can be produced by alternating left­right contractions of either all the axial muscle or just the precaudal axial muscle. As judged by changes in swimming speed, most of the locomotor power is generated precaudally and transmitted to the caudal fin by way of the skin and axial skeleton. The form of the traveling undulatory wave ­ as measured by tail-beat amplitude, propulsive wavelength and maximal caudal curvature ­ can be modulated by experimental control of the body's passive stiffness, which is a property of the skin, connective tissue and axial skeleton.
21
Donley, J. M., and K. A. Dickson. "Swimming kinematics of juvenile kawakawa tuna (Euthynnus affinis) and chub mackerel (Scomber japonicus)." Journal of Experimental Biology 203, no. 20 (October 15, 2000): 3103–16. http://dx.doi.org/10.1242/jeb.203.20.3103.
Full textAbstract:
The swimming kinematics of two active pelagic fishes from the family Scombridae were compared to test the hypothesis that the kawakawa tuna (Euthynnus affinis) uses the thunniform mode of locomotion, in which the body is held more rigid and undergoes less lateral movement in comparison with the chub mackerel (Scomber japonicus), which uses the carangiform swimming mode. This study, the first quantitative kinematic comparison of size-matched scombrids, confirmed significantly different swimming kinematics in the two species. Ten kawakawa (15.1-25.5 cm fork length, FL) and eight chub mackerel (14.0-23.4 cm FL), all juveniles, were videotaped at 120 Hz while swimming at several speeds up to their maximum sustained speed at 24 degrees C. Computerized motion analysis was used to digitize specific points on the body in sequential video frames, and kinematic variables were quantified from the progression of the points over time. At a given speed, kawakawa displayed a significantly greater tailbeat frequency, but lower stride length, tailbeat amplitude and propulsive wavelength, than chub mackerel when size effects were accounted for. Midline curvatures subdivided on the basis of X-rays into individual vertebral elements were used to quantify axial bending in a subset of the fish studied. Maximum intervertebral lateral displacement and intervertebral flexion angles were significantly lower along most of the body in kawakawa than in chub mackerel, indicating that the kawakawa undergoes less axial flexion than does the chub mackerel, resulting in lower tailbeat amplitudes. However, lateral movement at the tip of the snout, or yaw, did not differ significantly interspecifically. Despite these differences, the net cost of transport was the same in the two species, and the total cost was higher in the kawakawa, indicating that the tuna juveniles are not more efficient swimmers.
22
Hassan, M. El, V. Sobolik, A. Chamkha, and M. Kristiawan. "Kinematics of helical flow between concentric cylinders with axial through flow." International Journal of Heat and Mass Transfer 182 (January 2022): 121938. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2021.121938.
Full text
23
Brinkhorst, Michelle, Geert Streekstra, Joost van Rosmalen, Simon Strackee, and Steven Hovius. "Effects of axial load on in vivo scaphoid and lunate kinematics using four-dimensional computed tomography." Journal of Hand Surgery (European Volume) 45, no. 9 (August 3, 2020): 974–80. http://dx.doi.org/10.1177/1753193420943400.
Full textAbstract:
This in vivo study investigated the effect of axial load on lunate and scaphoid kinematics during flexion–extension and radial–ulnar deviation of the uninjured wrist using four-dimensional computed tomography. We found that applying axial load to the wrist results in a more flexed, radially deviated and pronated position of the lunate and scaphoid during flexion–extension of the wrist compared with when no load is applied. A larger pronation and supination range of the lunate and scaphoid was seen when the wrist was flexed and extended under axial load, whereas a larger flexion and extension range of the lunate and scaphoid occurred during radial–ulnar deviation of the wrist when axial load was applied.
24
Shi, Jin Yan. "Analysis on Kinematics between Piston and Cylinder Block in Swash-Plate Axial Piston Motor." Advanced Materials Research 1006-1007 (August 2014): 313–16. http://dx.doi.org/10.4028/www.scientific.net/amr.1006-1007.313.
Full textAbstract:
Analysis was carried out to the kinematics between piston and cylinder block in the axial piston motor. And the formula of displacement, velocity and acceleration of the movement of piston in the cylinder block were given, and some suggestions were also presented to help the design of the axial piston motor with high speed and high pressure in the further.
25
Ellerby, D. J., I. L. Y. Spierts, and J. D. Altringham. "Fast muscle function in the European eel (Anguilla anguillaL.) during aquatic and terrestrial locomotion." Journal of Experimental Biology 204, no. 13 (July 1, 2001): 2231–38. http://dx.doi.org/10.1242/jeb.204.13.2231.
Full textAbstract:
SUMMARYEels are capable of locomotion both in water and on land using undulations of the body axis. Axial undulations are powered by the lateral musculature. Differences in kinematics and the underlying patterns of fast muscle activation are apparent between locomotion in these two environments. The change in isometric fast muscle properties with axial location was less marked than in most other species. Time from stimulus to peak force (Ta) did not change significantly with axial position and was 82±6ms at 0.45BL and 93±3ms at 0.75BL, where BL is total body length. Time from stimulus to 90% relaxation (T90) changed significantly with axial location, increasing from 203±11ms at 0.45BL to 239±9ms at 0.75BL. Fast muscle power outputs were measured using the work loop technique. Maximum power outputs at ±5% strain using optimal stimuli were 17.3±1.3Wkg−1 in muscle from 0.45BL and 16.3±1.5Wkg−1 in muscle from 0.75BL. Power output peaked at a cycle frequency of 2Hz. The stimulus patterns associated with swimming generated greater force and power than those associated with terrestrial crawling. This decrease in muscle performance in eels may occur because on land the eel is constrained to a particular kinematic pattern in order to produce thrust against an underlying substratum.
26
Keeley, David W., Gretchen D. Oliver, Christopher P. Dougherty, and Michael R. Torry. "Lower Body Predictors of Glenohumeral Compressive Force in High School Baseball Pitchers." Journal of Applied Biomechanics 31, no. 3 (June 2015): 181–88. http://dx.doi.org/10.1123/jab.2011-0229.
Full textAbstract:
The purpose of this study was to better understand how lower body kinematics relate to peak glenohumeral compressive force and develop a regression model accounting for variability in peak glenohumeral compressive force. Data were collected for 34 pitchers. Average peak glenohumeral compressive force was 1.72% ± 33% body weight (1334.9 N ± 257.5). Correlation coefficients revealed 5 kinematic variables correlated to peak glenohumeral compressive force (P < .01, α = .025). Regression models indicated 78.5% of the variance in peak glenohumeral compressive force (R2 = .785, P < .01) was explained by stride length, lateral pelvis flexion at maximum external rotation, and axial pelvis rotation velocity at release. These results indicate peak glenohumeral compressive force increases with a combination of decreased stride length, increased pelvic tilt at maximum external rotation toward the throwing arm side, and increased pelvis axial rotation velocity at release. Thus, it may be possible to decrease peak glenohumeral compressive force by optimizing the movements of the lower body while pitching. Focus should be on both training and conditioning the lower extremity in an effort to increase stride length, increase pelvis tilt toward the glove hand side at maximum external rotation, and decrease pelvis axial rotation at release.
27
Dai, Yuan Xing, Tian Rui Zhang, Xue Wei Zhang, and Tian Biao Yu. "Kinematics and Dynamics Simulation of a New Type Direct-Drive NC Turret Tool Post." Applied Mechanics and Materials 325-326 (June 2013): 247–51. http://dx.doi.org/10.4028/www.scientific.net/amm.325-326.247.
Full textAbstract:
Building 3D model for a new type direct-drive NC Turret tool post, and introduce the model into ADAMS for further kinematics and dynamics simulation. In the kinematics simulation, observing the motion process of the direct-drive NC turret tool post and plots the trajectory of moving parts to a curve. Simulate the force condition of the NC turret tool post in actual situation, calculate the axial load and verify the clamping force in dynamics simulation.
28
Shimokochi, Yohei, Jatin P. Ambegaonkar, and Eric G. Meyer. "Changing Sagittal-Plane Landing Styles to Modulate Impact and Tibiofemoral Force Magnitude and Directions Relative to the Tibia." Journal of Athletic Training 51, no. 9 (September 1, 2016): 669–81. http://dx.doi.org/10.4085/1062-6050-51.10.15.
Full textAbstract:
Context: Ground reaction force (GRF) and tibiofemoral force magnitudes and directions have been shown to affect anterior cruciate ligament loading during landing. However, the kinematic and kinetic factors modifying these 2 forces during landing are unknown. Objective: To clarify the intersegmental kinematic and kinetic links underlying the alteration of the GRF and tibiofemoral force vectors secondary to changes in the sagittal-plane body position during single-legged landing. Design: Crossover study. Setting: Laboratory. Patients or Other Participants: Twenty recreationally active participants (age = 23.4 ± 3.6 years, height = 171.0 ± 9.4 cm, mass = 73.3 ± 12.7 kg). Intervention(s): Participants performed single-legged landings using 3 landing styles: self-selected landing (SSL), body leaning forward and landing on the toes (LFL), and body upright with flat-footed landing (URL). Three-dimensional kinetics and kinematics were recorded. Main Outcome Measure(s): Sagittal-plane tibial inclination and knee-flexion angles, GRF magnitude and inclination angles relative to the tibia, and proximal tibial forces at peak tibial axial forces. Results: The URL resulted in less time to peak tibial axial forces, smaller knee-flexion angles, and greater magnitude and a more anteriorly inclined GRF vector relative to the tibia than did the SSL. These changes led to the greatest peak tibial axial and anterior shear forces in the URL among the 3 landing styles. Conversely, the LFL resulted in longer time to peak tibial axial forces, greater knee-flexion angles, and reduced magnitude and a more posteriorly inclined GRF vector relative to the tibia than the SSL. These changes in LFL resulted in the lowest peak tibial axial and largest posterior shear forces among the 3 landing styles. Conclusions: Sagittal-plane intersegmental kinematic and kinetic links strongly affected the magnitude and direction of GRF and tibiofemoral forces during the impact phase of single-legged landing. Therefore, improving sagittal-plane landing mechanics is important in reducing harmful magnitudes and directions of impact forces on the anterior cruciate ligament.
29
Ritter, D. "Axial muscle function during lizard locomotion." Journal of Experimental Biology 199, no. 11 (November 1, 1996): 2499–510. http://dx.doi.org/10.1242/jeb.199.11.2499.
Full textAbstract:
It was recently reported that the epaxial muscles of a lizard, Varanus salvator, function to stabilize the trunk during locomotion, and it was suggested that this stabilizing role may be a shared derived feature of amniotes. This result was unexpected because it had previously been assumed that the epaxial muscles of lizards function to produce lateral bending during locomotion and that only in mammals and birds were the epaxial muscles active in stabilizing the trunk. These results and the inferences made from them lead to two questions. (1) Is the pattern of epaxial muscle activity observed in V. salvator representative of a basal lizard condition or is it a derived condition that evolved within lizards? (2) If the epaxial muscles do not produce lateral bending, which muscles do carry out this function? These questions were addressed by collecting synchronous electromyographic (EMG) and kinematic data from two lizard species during walking and running. EMG data were collected from the epaxial muscles of a lizard species from a basal clade, Iguana iguana, in order to address the first question. EMG data were collected from the hypaxial muscles of both Iguana iguana and Varanus salvator to address the second question. The timing of epaxial muscle activity in Iguana iguana relative to the kinematics of limb support and lateral trunk bending is similar to that observed in Varanus salvator, a finding that supports the hypothesis that the epaxial muscles stabilize the trunk during locomotion in lizards and that this stabilizing role is a basal feature of lizards. Therefore, a stabilizing function of the epaxial muscles is most parsimoniously interpreted as a basal amniote feature. In both Iguana iguana and Varanus salvator, the activity of two of the hypaxial muscles, the external oblique and rectus abdominis, is appropriately timed for the production of lateral bending. This indicates that elements of the hypaxial musculature, not the epaxial musculature, are the primary lateral bending muscles of lizards.
30
Cordo, P. J., V. S. Gurfinkel, T. C. Smith, P. W. Hodges, S. M. P. Verschueren, and S. Brumagne. "The sit-up: complex kinematics and muscle activity in voluntary axial movement." Journal of Electromyography and Kinesiology 13, no. 3 (June 2003): 239–52. http://dx.doi.org/10.1016/s1050-6411(03)00023-3.
Full text
31
GOTO, Hiroyuki, Masayuki FUJITSUKA, and Yutaka TANAKA. "2915 A Multi-Axial Materials Testing System Using 6-DOF Parallel Kinematics." Proceedings of the JSME annual meeting 2007.4 (2007): 15–16. http://dx.doi.org/10.1299/jsmemecjo.2007.4.0_15.
Full text
32
Wasserberger, Kyle W., Kenzie B. Friesen, Jessica L. Downs, Nicole M. Bordelon, and Gretchen D. Oliver. "Comparison of Pelvis and Trunk Kinematics Between Youth and Collegiate Windmill Softball Pitchers." Orthopaedic Journal of Sports Medicine 9, no. 8 (August 1, 2021): 232596712110218. http://dx.doi.org/10.1177/23259671211021826.
Full textAbstract:
Background: The windmill softball pitch is a dynamic sporting movement that places softball pitchers at high risk of injury. Unlike baseball, there is limited research into the mechanical differences between softball pitchers of varying skill levels. Purpose/Hypothesis: The purpose of this study was to compare pelvis and trunk kinematics between youth and collegiate softball pitchers. It was hypothesized that there would be significant differences in pelvis and trunk kinematics between these 2 groups. Study Design: Descriptive laboratory study. Methods: The pelvic and trunk kinematics of 90 softball pitchers were collected during full-effort pitching using a 3-dimensional motion capture system. Participants were grouped based on their age at the time of data collection (35 youth [mean age, 11 ± 1 years]; 55 collegiate [mean age, 20 ± 2 years]). We compared between-group differences in pelvic posterior tilt, lateral tilt, axial rotation, and axial rotation velocity as well as trunk extension, lateral flexion, axial rotation, and axial rotation velocity during the pitching phase between start of pitch and ball release (BR) using 1-dimensional statistical parametric mapping. Statistical significance was determined using Holmes-Šidák stepdown correction–adjusted P values ( P ′). Results: Compared with youth pitchers, collegiate pitchers exhibited a more posteriorly tilted pelvis from the moment of start of pitch until 94% of the way between start of pitch and BR ( P ′ = .002) and a more laterally flexed trunk toward the glove side from the moment of start of pitch until 71% of the way between start of pitch and BR ( P ′ = .010). Conclusion: Collegiate pitchers displayed a more posteriorly tilted pelvis and more laterally flexed trunk toward the glove side during the windmill pitching motion when compared with youth pitchers. Clinical Relevance: These findings add to the growing body of softball research and help elucidate mechanical differences between youth and collegiate softball pitchers.
33
Li, G., J. Gil, A. Kanamori, and S. L. Y. Woo. "A Validated Three-Dimensional Computational Model of a Human Knee Joint." Journal of Biomechanical Engineering 121, no. 6 (December 1, 1999): 657–62. http://dx.doi.org/10.1115/1.2800871.
Full textAbstract:
This paper presents a three-dimensional finite element tibio-femoral joint model of a human knee that was validated using experimental data. The geometry of the joint model was obtained from magnetic resonance (MR) images of a cadaveric knee specimen. The same specimen was biomechanically tested using a robotic/universal force-moment sensor (UFS) system and knee kinematic data under anterior-posterior tibial loads (up to 100 N) were obtained. In the finite element model (FEM), cartilage was modeled as an elastic material, ligaments were represented as nonlinear elastic springs, and menisci were simulated by equivalent-resistance springs. Reference lengths (zero-load lengths) of the ligaments and stiffness of the meniscus springs were estimated using an optimization procedure that involved the minimization of the differences between the kinematics predicted by the model and those obtained experimentally. The joint kinematics and in-situ forces in the ligaments in response to axial tibial moments of up to 10 Nm were calculated using the model and were compared with published experimental data on knee specimens. It was also demonstrated that the equivalent-resistance springs representing the menisci are important for accurate calculation of knee kinematics. Thus, the methodology developed in this study can be a valuable tool for further analysis of knee joint function and could serve as a step toward the development of more advanced computational knee models.
34
Yuan, S. X., and M. Xiao. "Experimental Study on the Mechanism of Axial Ultrasonic-Assisted Grinding." Advanced Materials Research 490-495 (March 2012): 2449–53. http://dx.doi.org/10.4028/www.scientific.net/amr.490-495.2449.
Full textAbstract:
This paper analysis the mechanism of axial ultrasonic-assisted grinding(AUAG), by establishing the kinematics model of a single grit; The reason why AUAG forces are more lower than conventional grinding(CG) forces is presented, and the experiments of the grinding force in AUAG comparison with CG were carried out. The results indicate that the grinding force of the superalloy in AUAG is about 40% to 50% less than that in CG.
35
Gonçalves, N., L. Domingues, A. Mashayekhi Sardoo, L. Radu, S. Rodrigues-Manica, A. Neto, R. Torres, et al. "AB0688 GAIT PATTERN DIFFERENCES BETWEEN PATIENTS WITH RADIOGRAPHIC AND NON-RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS, THE MyoSpA STUDY." Annals of the Rheumatic Diseases 79, Suppl 1 (June 2020): 1639.2–1640. http://dx.doi.org/10.1136/annrheumdis-2020-eular.5632.
Full textAbstract:
Background:Axial spondyloarthritis (axSpA) is a chronic inflammatory disease classified as radiographic (r-axSpA) or non-radiographic (nr-axSpA). Defining the gait patterns associated with these two groups can improve its detection and promote early intervention. In normal walking, body segments move around the joints as struts of an inverted pendulum. The resultant cyclic rotations contribute to the forward translation of the body, while minimizing muscle work and maintaining stability. Recent literature describes a decline in this pendulum-like mechanism associated with aging and some neurological diseases (Parkinson and multiple sclerosis).Objectives:The aim was to compare the 3D gait kinematics of patients with r-axSpA and nr-axSpA.Methods:A cross-sectional study was conducted on 54 participants (18-50 years old), 27 patients with axSpA (according to ASAS criteria, with less than 10 years since symptoms onset) and 27 healthy controls, matched by gender, age and level of physical activity. A sub-analysis was performed involving the whole group of patients classified as r-axSpA (n=14) and nr-axSpA (n=6). Subjects movement was reconstructed using a 3D full-body kinematic model (Kinetikos, Coimbra, Portugal) fed by 15 inertial sensors placed in the head, arms, trunk, pelvis, thighs, shanks and feet. 3D gait kinematics was characterised based on variables that analyse the body movement as a whole (e.g. center of mass displacement, speed), conventional spatiotemporal parameters (e.g. stance/swing time, step length) and joints kinematics time-normalized to 101 points, comprising the gait cycle from 0 to 100%. Nonparametric statistical tests were used.Results:In the r-axSpA group, 71,4% were male, with a mean age of 34.43±7.84 years and a BASDAI of 2.84±2.39, whereas in the nr-axSpA, 50% were male, with a mean age of 41.83±6.27 years and a BASDAI of 2.99±0.58. A statistically significant difference was observed in the displacement of the center of mass (with respect to the pelvis local coordinate system) along the anteroposterior axis between the two studied groups (H = 4.96, p = 0.03), with a mean rank displacement of 8.6 for r-axSpA and 15.00 for nr-axSpa, corresponding to a reduction in displacement of 38% (mean 0.00986 vs 0.01579m), in the r-axSpa group.Conclusion:Our preliminary results in r-axSpA subjects show a reduction of the pendulum mechanism. Although no significant segmental (kinematics) changes were observed, the sum of all studied variables result in a clear different gait pattern between the two groups. The observed decline can be an early sign of the inefficiency of the r-axSpA group to minimise the cost of transport of the center of mass during walking (i.e. increased instability). This study shows the potential of gait analysis to identify subjects who may benefit from early physiotherapy intervention.Disclosure of Interests:Nuno Gonçalves: None declared, Lúcia Domingues: None declared, Atlas Mashayekhi Sardoo: None declared, Lucian Radu: None declared, Santiago Rodrigues-Manica Speakers bureau: Jansse, MSD, Novartis, Agna Neto: None declared, Rita Torres: None declared, José Marona: None declared, Jaime Branco Speakers bureau: Vitoria, César Mendes: None declared, Ricardo Matias: None declared, Fernando Pimentel dos Santos Speakers bureau: Novartis, Pfizer, Biogen, Vitoria,
36
Fullenkamp, Adam M., Brian M. Campbell, C. Matthew Laurent, and Amanda Paige Lane. "The Contribution of Trunk Axial Kinematics to Poststrike Ball Velocity During Maximal Instep Soccer Kicking." Journal of Applied Biomechanics 31, no. 5 (October 2015): 370–76. http://dx.doi.org/10.1123/jab.2014-0188.
Full textAbstract:
To date, biomechanical analyses of soccer kicking have focused predominantly on lower-extremity motions, with little emphasis on the trunk and upper body. The purpose of this study was to evaluate differences in trunk axial kinematics between novice (n = 10) and skilled (n = 10) participants, as well as to establish the relationship of trunk axial motion and sagittal plane thigh rotation to poststrike ball velocity. Three-dimensional body segmental motion data were captured using high-resolution motion analysis (120 Hz) while each participant completed 5 maximal instep soccer-style kicks. The results demonstrate that skilled participants use 53% greater axial trunk range of motion compared with novice participants (P < .01), as well as 62% greater peak trunk rotation velocity (P < .01). The results also show a moderate, positive correlation of peak trunk rotation velocity with poststrike ball velocity (r = .57; P < .01), and peak hip flexion velocity with poststrike ball velocity (r = .63; P < .01). The current study highlights the potential for trunk rotation-specific training to improve maximum instep kick velocity in developing soccer athletes.
37
Wei, Xiu Ye, and Hai Yan Wang. "Dynamics Simulation Study of the Axial Piston Pump." Advanced Materials Research 706-708 (June 2013): 1323–26. http://dx.doi.org/10.4028/www.scientific.net/amr.706-708.1323.
Full textAbstract:
Kinematics analysis based on the structure parameters of SCY14-1B type axial piston pump is taken in this paper, and the motion laws of the pistons relative to the cylinder block and the swash plate are got. A matlab simulation of the motion law is taken and the comparison between theoretical analysis and simulated results is very good. We get the following conclusions: The displacement, velocity and acceleration of the motion of the piston relative to the swash plate is simple harmonic.The motion trajectory of the piston relative to the swash plate is an ellipse. The swash plate angle has a significant effect on the motion of the piston, which will inevitably affect the instantaneous flow rate of the pump and flow pulsation coefficient.
38
Salem, Walid, Cyrille Lenders, Jacques Mathieu, Nicole Hermanus, and Paul Klein. "In vivo three-dimensional kinematics of the cervical spine during maximal axial rotation." Manual Therapy 18, no. 4 (August 2013): 339–44. http://dx.doi.org/10.1016/j.math.2012.12.002.
Full text
39
Haj, Alaa, Asaf Weisman, and Youssef Masharawi. "Lumbar axial rotation kinematics in men with non-specific chronic low back pain." Clinical Biomechanics 61 (January 2019): 192–98. http://dx.doi.org/10.1016/j.clinbiomech.2018.12.022.
Full text
40
Anderson, B., J. Shultz, and B. Jayne. "Axial kinematics and muscle activity during terrestrial locomotion of the centipede Scolopendra heros." Journal of Experimental Biology 198, no. 5 (May 1, 1995): 1185–95. http://dx.doi.org/10.1242/jeb.198.5.1185.
Full textAbstract:
For centipedes moving steadily on a treadmill at speeds of 0.5, 1.0 and 1.5 L s-1, where L is body length, we obtained video tapes of movement that were synchronized with electromyograms (EMGs) from lateral flexor muscles at six standardized longitudinal positions. Field-by-field analysis of video tapes revealed posteriorly propagated waves of bending at all speeds. Muscle activity was also propagated posteriorly at the same speed as the kinematic wave, and EMGs of the lateral flexors were generally unilateral and alternating (between the left and right sides). The timing of EMG activity relative to lateral bending was consistent with electrical activity during the shortening of muscle fibers; therefore, activity of the axial musculature appears to cause lateral bending. Analysis of variance revealed widespread effects of speed on both kinematic and electromyographic variables, whereas longitudinal position within the centipede (between body segments 8 and 18) generally did not have significant effects on the same variables. For example, as speed increased from 0.5 to 1.5 L s-1, the amplitude of lateral displacement approximately doubled and the amplitude of lateral bending increased approximately threefold. Lag times (in seconds) indicating the propagation of kinematic and EMG events along the length of the centipede decreased significantly with speed. Phase lags among longitudinal sites decreased significantly with increased speed, indicating that the kinematic and EMG wavelengths increased with increased speed. EMG duration approximated 50 % of cycle duration and was unaffected by speed, and the phase of the EMG activity relative to lateral bending was also unaffected by locomotor speed. Hence, all results from all speeds are consistent with active bending of the axial segments during centipede locomotion, conflicting with the widely accepted hypothesis that lateral bending is imposed on the body by the metachronal stepping pattern of the legs and that bending is resisted by axial muscles.
41
Kotsifaki, Argyro, Rodney Whiteley, and Clint Hansen. "Dual Kinect v2 system can capture lower limb kinematics reasonably well in a clinical setting: concurrent validity of a dual camera markerless motion capture system in professional football players." BMJ Open Sport & Exercise Medicine 4, no. 1 (December 2018): e000441. http://dx.doi.org/10.1136/bmjsem-2018-000441.
Full textAbstract:
ObjectivesTo determine whether a dual-camera markerless motion capture system can be used for lower limb kinematic evaluation in athletes in a preseason screening setting.DesignDescriptive laboratory study.SettingLaboratory setting.ParticipantsThirty-four (n=34) healthy athletes.Main outcome measuresThree dimensional lower limb kinematics during three functional tests: Single Leg Squat (SLS), Single Leg Jump, Modified Counter-movement Jump. The tests were simultaneously recorded using both a marker-based motion capture system and two Kinect v2 cameras using iPi Mocap Studio software.ResultsExcellent agreement between systems for the flexion/extension range of motion of the shin during all tests and for the thigh abduction/adduction during SLS were seen. For peak angles, results showed excellent agreement for knee flexion. Poor correlation was seen for the rotation movements.ConclusionsThis study supports the use of dual Kinect v2 configuration with the iPi software as a valid tool for assessment of sagittal and frontal plane hip and knee kinematic parameters but not axial rotation in athletes.
42
Sha, D., J. Stick, N. Elvin, and H. M. Clayton. "3D kinematics of the equine metacarpophalangeal joint at walk and trot." Veterinary and Comparative Orthopaedics and Traumatology 02, no. 02 (2007): 86–91. http://dx.doi.org/10.1160/vcot-07-01-0011.
Full textAbstract:
SummaryThe metacarpophalangeal (MCP) joint and its supporting soft tissues are common sites of injury in athletic horses. Equine gait analysis has focused on 2D analysis in the sagittal plane and little information is available which describes 3D motions of the MCP joint and their possible role in the development of injuries. The aim was to characterize the 3D rotations of the equine MCP joint during walking and trotting. Three-dimensional trajectories of marker triads fixed rigidly to the third metacarpus and proximal phalanx of the right forelimb of healthy horses were recorded at walk (n=4) and trot (n=6) at 120 Hz using eight infra-red cameras. Kinematics of the MCP joint were calculated in terms of helical angles between the two segments using singular-value decomposition and spatial attitude methods. The ranges of motion were: flexion/extension: 62 ± 7° at walk, 77 ± 5° at trot; adduction/abduction: 13 ± 7° at walk, 18 ± 7° at trot; and axial rotation: 6 ± 3° at walk, 9 ± 5° at trot. Flexion/extension had a consistent pattern and amplitude in all horses and appeared to be coupled with adduction/abduction, such that stance phase extension was accompanied by abduction and swing phase flexion was accompanied by adduction. Axial rotation was small in amount and the direction varied between horses but was consistent within an individual for the two gaits.
43
Sturnick, Daniel R., Charles L. Saltzman, Albert H. Burstein, Matthew A. Hamilton, and Jonathan T. Deland. "Kinematics of a Pyrocarbon Ankle Spacer for the Treatment of Arthritic Disease." Foot & Ankle Orthopaedics 4, no. 4 (October 1, 2019): 2473011419S0041. http://dx.doi.org/10.1177/2473011419s00414.
Full textAbstract:
Category: Ankle, Ankle Arthritis Introduction/Purpose: Treatment options for ankle arthritis in younger patients are currently limited. Since the longevity of modern total ankle replacements is not sufficient for this patient population, ankle arthrodesis is typically utilized when joint preserving treatment is not a viable option. A new procedure using a pyrocarbon ankle spacer has been developed as a potential alternative, allowing for talar articular resurfacing for pain relief with minimal bone resection. The objective of this study was to assess whether this pyrocarbon ankle spacer could provide normal ankle kinematics as the native ankle joint using cadaveric gait simulation. Methods: Five mid-tibia cadaveric specimens without deformity and no history of lower limb injury or surgery were utilized. The stance phase of gait was simulated for each specimen using a six degree-of-freedom robotic device. A force plate was moved relative to stationary specimen through an inverse tibial kinematic path calculated from in vivo data while extrinsic tendons were actuated using physiologic loads (Figure 1A). Magnitudes of load were scaled to that of 25% bodyweight. Ankle kinematics were measured from reflective markers attached to the tibia and talus via surgical pins. The pyrocarbon ankle spacer (Exactech, Gainesville, FL, USA) was implanted in a nest formed 3-4 mm in depth on the talar articular surface using a custom burring technique (Figure 1B). Ankle spacer kinematics were compared to 95% confidence intervals of native, intact ankle joint kinematics to assess agreement. Results: Outcomes revealed no significant difference in ankle joint kinematics between the native, intact condition and post- pyrocarbon spacer implantation (Figure 1C). This result was consistent for the sagittal, coronal and axial planes of motion. Conclusion: The results of this study demonstrate that a pyrocarbon spacer permits normal ankle kinematics. Further, the device was observed to be stable in the joint throughout simulations. While the testing was performed at 25% bodyweight for analyses on all specimens, load magnitudes were also increased up to 75% on a subset of specimens and the structural integrity of the device remained pristine. With these findings, we concluded that the pyrocarbon spacer device offers promising potential as a treatment option for ankle arthritis.
44
Hamai, Satoshi, Ken Okazaki, Satoru Ikebe, Koji Murakami, Hidehiko Higaki, Hiroyuki Nakahara, Takeshi Shimoto, Hideki Mizu-uchi, Yukio Akasaki, and Yukihide Iwamoto. "In Vivo Kinematics of Healthy and Osteoarthritic Knees During Stepping Using Density-Based Image-Matching Techniques." Journal of Applied Biomechanics 32, no. 6 (December 2016): 586–92. http://dx.doi.org/10.1123/jab.2016-0112.
Full textAbstract:
The purpose of this study was to investigate in vivo kinematics in healthy and osteoarthritic (OA) knees during stepping using image-matching techniques. Six healthy volunteers and 14 patients with a medial OA knee before undergoing total knee arthroplasty performed stepping under periodic anteroposterior radiograph images. We analyzed the three-dimensional kinematic parameters of knee joints using radiograph images and CT-derived digitally reconstructed radiographs. The average extension/flexion angle ranged 6°/53° and 16°/44° in healthy and OA knees, with significant difference in extension (P = .02). The average varus angle was –2° and 6° in healthy and OA knees, with a significant difference (P = .03). OA knees showed 1.7° of significantly larger varus thrust (P = .04) and 4.2 mm of significantly smaller posterior femoral rollback (P = .04) compared with healthy knees. Coronal limb alignment in OA knees significantly correlated with varus thrust (R2 = .36, P = .02) and medial shift of the femur (R2 = .34, P = .03). Both normal and OA knees showed no transverse plane instability, including anteroposterior, mediolateral directions, or axial rotation. In conclusion, OA knees demonstrated different kinematics during stepping from normal knees: less knee extension, larger varus thrust, less posterior translation, and larger medial shift.
45
Kuzmin, A. O., S. M. Stazhkov, N. V. Tarasova, and P. I. Valikov. "Fractional step method in problems of hydromechanical processes in piston-cylinder unit of axial piston swash plate hydraulic machines." Journal of «Almaz – Antey» Air and Space Defence Corporation, no. 4 (December 30, 2019): 60–66. http://dx.doi.org/10.38013/2542-0542-2019-4-60-66.
Full textAbstract:
Having analyzed the piston-cylinder unit kinematics, we obtained an equation for the clearance height in the piston-cylinder unit for the case of low speeds, the equation being the basis for Reynolds equation for the lubricant layer of the piston mechanism. By a numerical experiment using the fractional step method, we built a pressure field for two different cases of the piston mechanism kinematics, and compared the bearing capacity of the hydrodynamic force. It was revealed analytically and with the help of a numerical experiment that when the piston rolls in the edges of the guide bushing, the total hydrodynamic force significantly exceeds the force created when the piston slides in the bushing.
46
WASSERSUG, RICHARD J., and KARIN VON SECHENDORF HOFF. "The Kinematics of Swimming in Anuran Larvae." Journal of Experimental Biology 119, no. 1 (November 1, 1985): 1–30. http://dx.doi.org/10.1242/jeb.119.1.1.
Full textAbstract:
The kinematics of swimming in tadpoles from four species of anurans (Rana catesbeiana Shaw, Rana septentrionalis Baird, Rana clamitans Latreille and Bufo americanus Holbrook) was studied using computer-assisted analysis of high speed (≥200 frames s−1) ciné records. 1. Tadpoles exhibit the same positive, linear relationship between tail beat frequency and specific swimming speed commonly reported for subcarangiform fishes. 2. Tadpoles show an increase in the maximum amplitude of the tail beat with increasing swimming speed up to approximately 4 lengths s−1. Above 4 lengths s−1, amplitude approaches an asymptote at approximately 25 % of length. 3. Tadpoles with relatively longer tails have lower specific amplitudes. 4. Froude efficiencies for tadpoles are similar to those reported for most subcarangiform fishes. 5. Bufo larvae tend to have higher specific maximum amplitude, higher tail beat frequencies, lower propeller efficiencies (at least at intermediate speeds) and substantially less axial musculature than do comparable-sized Rana larvae. These differences may relate to the fact that Bufo larvae are noxious to many potential predators and consequently need not rely solely on locomotion for defence. 6. Tadpoles exhibit larger amounts of lateral movement at the snout than do most adult fishes. 7. The point of least lateral movement during swimming in tadpoles is at the level of the semi-circular canals, as assumed in models on the evolution of the vertebrate inner ear. 8. Passive oscillation of anaesthetized and curarized tadpoles at the base of their tail produces normal kinematics in the rest of the tail. This supports the idea that muscular activity in the posterior, tapered portion of the tadpole tail does not serve a major role in thrust production during normal, straightforward swimming at constant velocity. 9. The angle of incidence and lateral velocity of the tail tip as it crosses the path of motion are not consistent with theoretical predictions of how thrust should be generated. The same parameters evaluated at the high point of the tail fin (approximately midtail) suggest that that portion of the tail generates thrust most effectively. 10. Ablation of the end of the tail in passively oscillated tadpoles confirms that the terminal portion of the tadpole tail serves to reduce excessive amplitude in the more anterior portion of the tail, where most thrust is generated. 11. The posterior portion of the tail is important in reducing turbulence around a tadpole. It may also function to produce thrust during irregular, intricate movements, such as swimming backwards. 12. Tadpoles are comparable to subcarangiform fishes of similar size in their maximum swimming speed and mechanical efficiency, despite the fact that they have much less axial musculature and lack the elaborate skeletal elements that stiffen the fins in fishes. The simple shape of the tadpole tail appears to allow these animals efficient locomotion over short distances and high manoeuvrability, while maintaining the potential for rapid morphological change at metamorphosis.
47
GOTO, Hiroyuki, Yutaka TANAKA, and Hiroyuki NIHASHI. "S1102-1-2 A Multi-Axial Materials Testing System Using 6-DOF Parallel Kinematics." Proceedings of the JSME annual meeting 2010.4 (2010): 167–68. http://dx.doi.org/10.1299/jsmemecjo.2010.4.0_167.
Full text
48
Yang, King H., and Albert L. King. "Neck Kinematics in Rear-End Impacts." Pain Research and Management 8, no. 2 (2003): 79–85. http://dx.doi.org/10.1155/2003/839740.
Full textAbstract:
The purpose of this study was to document the kinematics of the neck during low-speed rear-end impacts. In a series of experiments reported by Deng et al (2000), a pneumatically driven mini-sled was used to study cervical spine motion using six cadavers instrumented with metallic markers at each cervical level, a 9-accelerometer mount on the head, and a tri-axial accelerometers on the thorax. A 250-Hz x-ray system was used to record marker motion while acceleration data were digitized at 10,000 Hz. Results show that, in the global coordinate system, the head and all cervical vertebrae were primarily in extension during the entire period of x-ray data collection. In local coordinate systems, upper cervical segments were initially in relative flexion while lower segments were in extension. Facet joint capsular stretch ranged from 17 to 97%. In the vertical direction, the head and T1 accelerated upward almost instantaneously after impact initiation while there was delay for the head in the horizontal direction. This combination was the result of a force vector which was pointed in the forward and upward direction to generate an extension moment. Upward ramping of the torso was larger in tests with a 20-deg seatback angle. The study concluded that the kinematics of the neck is rather complicated and greatly influenced by the large rotations of the thoracic spine. Significant posterior shear deformation was found, as evidenced by the large facet capsular stretch. Although the neck forms a 'mild' S-shaped curve during whiplash, using its shape as an injury mechanism can be misleading because the source of pain is likely to be located in the facet capsules.
49
Li, Zhi Gang, Qiu Hong Lin, Dong Yan Zhao, and Li Quan Wang. "The Structural Design and Optimization for the Inner-Frame of Subsea Flange Connection Tool." Key Engineering Materials 419-420 (October 2009): 197–200. http://dx.doi.org/10.4028/www.scientific.net/kem.419-420.197.
Full textAbstract:
Subsea Flange Connection Tool (SFCT) is a remote apparatus for connecting underwater bolted flanges, especially applied in the offshore pipeline laying. As a pivotal unit construction of SFCT, Inner-frame enables the Bolt Handling Tool and Nut Handling Tool to move separately in axial direction and together in circumferential direction with the reference of the pipe’s axes. This paper presents the Inner-frame’s structural concept and builds its kinematics-equivalent mechanism models, carrying on the kinematics analysis of Inner-frame; to improve the energy efficiency, models the Inner-frame’s rotation-mechanism parametrically and establishes an objective with the minimum power consumption, which generates the optimal positions for the hinged-hydraulic cylinder’s joints with Box and Pendulum.
50
Pan, Ye-Chen, R. A. Scott, and A. Galip Ulsoy. "Dynamic Modeling and Simulation of Flexible Robots With Prismatic Joints." Journal of Mechanical Design 112, no. 3 (September 1, 1990): 307–14. http://dx.doi.org/10.1115/1.2912609.
Full textAbstract:
A dynamic model for flexible manipulators with prismatic joints is presented in Part I of this study. Floating frames following a nominal rigid body motion are introduced to describe the kinematics of the flexible links. A Lagrangian approach is used in deriving the equations of motion. The work done by the rigid body axial force through the axial shortening of the link due to transverse deformations is included in the Lagrangian function. Kinematic constraint equations are used to describe the compatibility conditions associated with revolute joints and prismatic joints, and incorporated into the equations of motion by Lagrange multipliers. The small displacements due to the flexibility of the links are then discretized by a displacement based finite element method. Equations of motion are derived for the cases of prescribed rigid body motion as well as prescribed joint torques/forces through application of Lagrange’s equations. The equations of motion and the constraint equations result in a set of differential algebraic equations. A numerical procedure combining a constraint stabilization method and a Newmark direct integration scheme is then applied to obtain the system response. An example, previously treated in the literature, is presented to validate the modeling and solution methods used in this study.