Hindlimb muscular activity, kinetics and kinematics of cats jumping to their maximum achievable heights

Cats were trained to jump from a force platform to their maximum achievable heights. Vertical ground reaction forces developed by individual hindlimbs showed that the propulsion phase consists of two epochs. During the initial “preparatory phase' the cat can traverse many different paths. Irrespective of the path traversed, however, the cat always attains the same position, velocity and momentum at the end of this phase. Starting from this dynamic state the cat during the subsequent “launching phase' (about 150 ms long) generates significant propulsion as its hindlimbs develop force with identical, stereotypic profiles. Cinematographic data, electromyographic data, and computed torques about the hip, knee and ankle joints indicate that during the jump proximal extensor musculature is activated before distal musculature. During terminal experiments when the hindlimb was set at positions corresponding to those in the jump, isometric torques produced by tetanic stimulation of groups of extensor and flexor muscles were compared with computed torques developed by the same cat during previous jumps. These comparisons suggest that extensor muscles of the hindlimb are fully activated during the maximal vertical jump.

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Lower-Extremity-Joint Cryotherapy Does Not Affect Vertical Ground-Reaction Forces during Landing

Journal of Sport Rehabilitation ◽

10.1123/jsr.10.2.132 ◽

2001 ◽

Vol 10 (2) ◽

pp. 132-142 ◽

Cited By ~ 12

Author(s):

Andrew G Jameson ◽

Stephen J Kinzey ◽

Jeffrey S Hallam

Keyword(s):

Repeated Measures ◽

Vertical Jump ◽

Reaction Force ◽

Vertical Ground Reaction Force ◽

Physically Active ◽

Before And After ◽

Reaction Forces ◽

Vertical Ground ◽

Chronic Injuries ◽

Vertical Ground Reaction Forces

Context:Cryotherapy is commonly used in the care of acute and chronic injuries. It decreases pain, reduces swelling, and causes vasoconstriction of blood vessels. Its detrimental effects on motor activity might predispose physically active individuals to further injury.Objective:To examine the effects of cryotherapy on vertical-ground-reaction-force (VGRF) during a 2-legged landing from a 2-legged targeted vertical jump.Design:2 × 4 MANOVA with repeated measures.Setting:Biomechanics laboratory.Participants:10 men, means: 22.40 ± 1.26 years, 76.01 ± 26.95 kg, 182.88 ± 6.88 cm.Intervention:VGRF during landing from a targeted vertical jump (90% of maximum) was measured before and after four 20-minute cryotherapy treatments.Results:There were no significant differences in VGRF as a result of cryotherapy.Conclusion:Under the constraints of this study there is no evidence that returning to activity immediately after cryotherapy predisposes an athlete to injury because of a change in VGRF.

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Interlimb Force Coordination in Bipedal Dance Jumps: Comparison Between Experts and Novices

Journal of Applied Biomechanics ◽

10.1123/jab.2017-0216 ◽

2018 ◽

Vol 34 (6) ◽

pp. 462-468

Author(s):

Hai-Jung Steffi Shih ◽

Danielle N. Jarvis ◽

Pamela Mikkelsen ◽

Kornelia Kulig

Keyword(s):

Transition Phase ◽

Specific Rate ◽

Vector Coding ◽

Force Coordination ◽

Reaction Forces ◽

Vertical Ground ◽

Rate Controlled ◽

Vertical Ground Reaction Forces ◽

Propulsion Phase ◽

Weight Acceptance

Bipedal tasks require interlimb coordination that improves with practice and acquisition of skills. The purpose of this study was to compare interlimb force coordination during dance-specific rate-controlled consecutive bipedal jumps (sautés) between expert dancers and nondancers. To analyze coordination of vertical ground reaction forces recorded under each leg, the vector coding approach was used. Although there were no differences in the patterns of interlimb force coordination between groups, the dancers exhibited less variability of interlimb force coordination during the transition phase from weight acceptance to propulsion as well as during the propulsion phase itself. The interlimb force coordination variability was associated with task performance only during the transition phase, which highlights the potential importance of control during this phase. In conclusion, expert dancers were better at reducing interlimb force coordination variability during the task-relevant transition phase, which was related to better performance at maintaining jump rate and jump height consistency.

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Use of an instrument sandwiched between the hoof and shoe to measure vertical ground reaction forces and three-dimensional acceleration at the walk, trot, and canter in horses

American Journal of Veterinary Research ◽

10.2460/ajvr.2000.61.979 ◽

2000 ◽

Vol 61 (8) ◽

pp. 979-985 ◽

Cited By ~ 29

Author(s):

Makoto Kai ◽

Osamu Aoki ◽

Atsushi Hiraga ◽

Hironori Oki ◽

Mikihiko Tokuriki

Keyword(s):

Three Dimensional ◽

Ground Reaction Forces ◽

Reaction Forces ◽

Vertical Ground ◽

Vertical Ground Reaction Forces

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Joint angle estimation with wavelet neural networks

Scientific Reports ◽

10.1038/s41598-021-89580-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Saaveethya Sivakumar ◽

Alpha Agape Gopalai ◽

King Hann Lim ◽

Darwin Gouwanda ◽

Sunita Chauhan

Keyword(s):

Gait Analysis ◽

Real Time ◽

Monitoring Applications ◽

Reaction Forces ◽

Multiple Sensor ◽

Vertical Ground ◽

Overall Performance ◽

Gait Monitoring ◽

Vertical Ground Reaction Forces ◽

And Control

AbstractThis paper presents a wavelet neural network (WNN) based method to reduce reliance on wearable kinematic sensors in gait analysis. Wearable kinematic sensors hinder real-time outdoor gait monitoring applications due to drawbacks caused by multiple sensor placements and sensor offset errors. The proposed WNN method uses vertical Ground Reaction Forces (vGRFs) measured from foot kinetic sensors as inputs to estimate ankle, knee, and hip joint angles. Salient vGRF inputs are extracted from primary gait event intervals. These selected gait inputs facilitate future integration with smart insoles for real-time outdoor gait studies. The proposed concept potentially reduces the number of body-mounted kinematics sensors used in gait analysis applications, hence leading to a simplified sensor placement and control circuitry without deteriorating the overall performance.

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Hip and Knee Kinematics and Kinetics During Landing Tasks After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis

Journal of Athletic Training ◽

10.4085/1062-6050-334-16 ◽

2018 ◽

Vol 53 (2) ◽

pp. 144-159 ◽

Cited By ~ 12

Author(s):

Adam S. Lepley ◽

Christopher M. Kuenze

Keyword(s):

Ligament Reconstruction ◽

Cruciate Ligament ◽

Meta Analysis ◽

Knee Extension ◽

Injured Limb ◽

Reaction Forces ◽

Vertical Ground ◽

Anterior Cruciate ◽

Vertical Ground Reaction Forces ◽

Kinematics And Kinetics

Objective: To evaluate the current evidence concerning kinematic and kinetic strategies adopted during dynamic landing tasks by patients with anterior cruciate ligament reconstruction (ACLR). Data Sources: PubMed, Web of Science. Study Selection: Original research articles that evaluated kinematics or kinetics (or both) during a landing task in those with a history of ACLR were included. Data Extraction: Methodologic quality was assessed using the modified Downs and Black checklist. Means and standard deviations for knee or hip (or both) kinematics and kinetics were used to calculate Cohen d effect sizes and corresponding 95% confidence intervals between the injured limb of ACLR participants and contralateral or healthy matched limbs. Data were further stratified by landing tasks, either double- or single-limb landing. A random-effects–model meta-analysis was used to calculate pooled effect sizes and 95% confidence intervals. Data Synthesis: The involved limbs of ACLR patients demonstrated clinically and significantly lower knee-extension moments during double-legged landing compared with healthy contralateral limbs and healthy control limbs (Cohen d range = −0.81 to −1.23) and decreased vertical ground reaction forces when compared with healthy controls, regardless of task (Cohen d range = −0.39 to −1.75). Conclusions: During single- and double-legged landing tasks, individuals with ACLR demonstrated meaningful reductions in injured-limb knee-extension moments and vertical ground reaction forces. These findings indicate potential unloading of the injured limb after ACLR, which may have significant implications for secondary ACL injury and long-term joint health.

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