A Biomechanical Study of Side Steps at Different Distances

2013 ◽  
Vol 29 (3) ◽  
pp. 336-345 ◽  
Author(s):  
Yuki Inaba ◽  
Shinsuke Yoshioka ◽  
Yoshiaki Iida ◽  
Dean C. Hay ◽  
Senshi Fukashiro
Keyword(s):  
Inverse Dynamics ◽  
Center Of Mass ◽  
Reaction Force ◽  
Biomechanical Study ◽  
Joint Torque ◽  
Large Power ◽  
Lower Extremity Muscle ◽  
Ankle Joints ◽  
Hip Abduction ◽  
Muscle Groups

Lateral quickness is a crucial component of many sports. However, biomechanical factors that contribute to quickness in lateral movements have not been understood well. Thus, the purpose of this study was to quantify 3-dimensional kinetics of hip, knee, and ankle joints in side steps to understand the function of lower extremity muscle groups. Side steps at nine different distances were performed by nine male subjects. Kinematic and ground reaction force data were recorded, and net joint torque and work were calculated by a standard inverse-dynamics method. Extension torques and work done at hip, knee, and ankle joints contributed substantially to the changes in side step distances. On the other hand, hip abduction work was not as sensitive to the changes in the side step distances. The main roles of hip abduction torque and work were to accelerate the center of mass laterally in the earlier phase of the movement and to keep the trunk upright, but not to generate large power for propulsion.

scholarly journals A biomechanical study of load carriage by two paired subjects in response to increased load mass

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guillaume Fumery ◽  
Nicolas A. Turpin ◽  
Laetitia Claverie ◽  
Vincent Fourcassié ◽  
Pierre Moretto
Keyword(s):  
Recovery Rate ◽  
Energy Recovery ◽  
Mechanical Energy ◽  
Center Of Mass ◽  
Step Length ◽  
Biomechanical Study ◽  
Load Carriage ◽  
Joint Torque ◽  
Total Mechanical Energy ◽  
Load Mass

AbstractThe biomechanics of load carriage has been studied extensively with regards to single individuals, yet not so much with regards to collective transport. We investigated the biomechanics of walking in 10 paired individuals carrying a load that represented 20%, 30%, or 40% of the aggregated body-masses. We computed the energy recovery rate at the center of mass of the system consisting of the two individuals plus the carried load in order to test to what extent the pendulum-like behavior and the economy of the gait were affected. Joint torque was also computed to investigate the intra- and inter-subject strategies occurring in response to this. The ability of the subjects to move the whole system like a pendulum appeared rendered obvious through shortened step length and lowered vertical displacements at the center of mass of the system, while energy recovery rate and total mechanical energy remained constant. In parallel, an asymmetry of joint moment vertical amplitude and coupling among individuals in all pairs suggested the emergence of a leader/follower schema. Beyond the 30% threshold of increased load mass, the constraints at the joint level were balanced among individuals leading to a degraded pendulum-like behavior.

Prediction of the Lower Extremity Muscle Forces During Stair Ascent and Descent

2008 ◽  
Author(s):  
Ali Selk Ghafari ◽  
Ali Meghdari ◽  
Gholam Reza Vossoughi
Keyword(s):  
Lower Extremity ◽  
Inverse Dynamics ◽  
Sagittal Plane ◽  
Optimization Technique ◽  
The Elderly ◽  
Plantar Flexors ◽  
Stair Ascent ◽  
Lower Extremity Muscle ◽  
Anatomical Classification ◽  
Muscle Groups

An inverse dynamics musculoskeletal model of the lower extremity was combined with an optimization technique to estimate individual muscular forces and powers during stair ascent and descent. Eighteen Hill-type musculotendon actuators per leg were combined into the eleven functional muscle groups based on anatomical classification to drive the model in the sagittal plane. Simulation results illustrate the major functional differences in plantar flexors of the ankle and extensors of the knee and hip joints during ascent and descent. The results of this study not only could be employed to evaluate the rehabilitation results in the elderly but also could be used to design more anthropometric assistive devices with optimum power consumption.

scholarly journals Segmental contributions to the ground reaction force in the single support phase of gait

2014 ◽  
Vol 5 (2) ◽  
pp. 37-52 ◽  
Author(s):  
D. S. Mohan Varma ◽  
S. Sujatha
Keyword(s):  
Ground Reaction Force ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Center Of Mass ◽  
Reaction Force ◽  
Experimental Studies ◽  
Vertical Component ◽  
Frontal Plane ◽  
Mathematical Form ◽  
Dynamics Models

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.

A NEW STABILITY CRITERION FOR HUMAN SEATED TASKS WITH GIVEN POSTURES

2012 ◽  
Vol 09 (03) ◽  
pp. 1250015 ◽  
Author(s):  
BRADLEY HOWARD ◽  
JINGZHOU YANG
Keyword(s):  
Stability Analysis ◽  
Stability Criterion ◽  
Center Of Mass ◽  
Reaction Force ◽  
Joint Torque ◽  
Human Model ◽  
Digital Human Model ◽  
Applied Forces ◽  
The Stability ◽  
Digital Human

In digital human modeling (DHM), the analysis of postural stability has five main goals: to determine if a posture is stable or unstable through an explicit criterion; to quantify the level of stability or provide a margin of stability that accounts for the height of the center of mass (COM) above the support plane(s); to be valid in the presence of externally applied forces and moments; be able to assess stability when multiple noncoplanar support planes exist, as is the case with seated postures; and to give insight into the support reaction force (SRF) distribution. To date, there is not a method for analyzing stability that can effectively meet each goal. This paper presents a new stability criterion and stability analysis that accomplishes each intended goal. The stability analysis is derived from the calculation of joint torque using the recursive Lagrangian dynamic formulation. A 56-degree-of-freedom (DOF) articulated digital human model is used to model seated postures to demonstrate the proposed stability criterion. Different given postures with different external load cases are presented.

Minimal Kinematic Model for Inverse Dynamic Analysis of Gait

2014 ◽  
Author(s):  
D. S. Mohan Varma ◽  
S. Sujatha
Keyword(s):  
Inverse Dynamics ◽  
Sagittal Plane ◽  
Center Of Mass ◽  
Reaction Force ◽  
Kinematic Model ◽  
Parameter Estimates ◽  
Dynamics Model ◽  
Kinematic Data ◽  
Segment Model ◽  
Internal Joint

The objective of this work is to develop an inverse dynamics model that uses minimal kinematic inputs to estimate the ground reaction force (GRF). The human body is modeled with 14 rigid segments and a circular ankle-foot-roll-over shape (AFROS) for the foot-ground interaction. The input kinematic data and body segment parameter estimates are obtained from literature. Optimization is used to ensure that the kinematic data satisfy the constraint that the swing leg clears the ground in the single support (SS) phase. For the SS phase, using the segment angles as the generalized degrees of freedom (DOF), the kinematic component of the GRF is expressed analytically as the summation of weighted kinematics of individual segments. The weighting functions are constants that are functions of the segment masses and center of mass distances. Using this form of the equation for GRF, it is seen that the kinematics of the upper body segments do not contribute to the vertical component GRFy in SS phase enabling the reduction of a 16-DOF 14-segment model to a 10-DOF 7-segment model. It is seen that the model can be further reduced to a 3-DOF model for GRFy estimation in the SS phase of gait. The horizontal component GRFx is computed assuming that the net GRF vector passes through the center of mass (CoM). The GRF in double support phase is assumed to change linearly from one foot to the other. The sagittal plane internal joint forces and moments acting at the ankle, knee and hip are computed using the 3-DOF model and the 10-DOF model and compared with the results from literature. An AFROS and measurements of the stance shank and thigh rotations in the sagittal plane, and of the lower trunk (or pelvis) in the frontal plane provide sufficient kinematics in an inverse dynamics model to estimate the GRF and joint reaction forces and moments. Such a model has the potential to simplify gait analysis.

scholarly journals Non-Slender n-Link Chain Driven by Single-Joint and Multi-joint Muscle Actuators: Closed-Form Dynamic Equations and Joint Reaction Forces

2021 ◽  
Vol 11 (15) ◽  
pp. 6860
Author(s):  
Andrea Biscarini
Keyword(s):  
Closed Form ◽  
Center Of Mass ◽  
Reaction Force ◽  
Angular Acceleration ◽  
Joint Torque ◽  
Dynamic Equations ◽  
Unique Contribution ◽  
Revolute Joints ◽  
Joint Reaction Forces ◽  
Analytical Quantification

The author has derived the closed-form dynamic equations for a planar musculoskeletal chain composed of a generic number n of rigid links connected by ideal revolute joints. Single-joint and multi-joint muscles have been modeled as linear force actuators that can span from one joint to all the joints of the chain. The generic shape and size of each individual link of the chain accounts for different alignments among the center of mass of the link, the centers of rotation of the joints that articulate the link with its neighbors, and the points of application of the muscle forces and the possible contact external resistances acting on the link. The joint torque and the reaction force acting on each joint have been determined in closed-form by analytical quantification of the unique contribution of each individual kinematic and kinetic variable: (1) force of each single-joint or multi-joint muscle spanning or non-spanning the joint; (2) weight and contact external resistances acting on each individual link of the chain; (3) position, angular velocity, and angular acceleration of each individual link of the chain. The analytical results derived in this study can be applied to multilink musculoskeletal chains with deep/superficial and segmental/global muscles.

KINEMATIC AND KINETIC ADAPTATIONS IN THE LOWER EXTREMITIES OF EXPERIENCED WEARERS DURING HIGH-HEELED GAIT

2014 ◽  
Vol 26 (03) ◽  
pp. 1450042 ◽  
Author(s):  
Hui-Lien Chien ◽  
Tung-Wu Lu ◽  
Ming-Wei Liu ◽  
Shih-Wun Hong ◽  
Chien-Chung Kuo
Keyword(s):  
Ground Reaction Force ◽  
External Rotation ◽  
Center Of Mass ◽  
Reaction Force ◽  
Lower Extremities ◽  
Heel Strike ◽  
Ankle Stability ◽  
Flexion Extension ◽  
Hip Abduction ◽  
The Stability

High-heeled shoes are associated with falling, leading to injuries such as fracture and ankle sprain. The study aimed to investigate the kinematic and kinetic adaptations in the lower extremities resulting from habitual use of high-heeled shoes. A total of 15 female experienced wearers and 15 matched controls walked with high-heeled shoes (7.3 cm) while kinematic and ground reaction force data were measured and used to calculate the joint angles and moments, as well as the temporal-distance parameters. Compared with inexperienced wearers, experienced wearers appeared to adopt a specific control strategy to improve the stability of the support ankle and knee while preventing excessive loading at the knee and hip. Increased hip abduction during early stance phase and increased pelvis rotation toward the ipsilateral side at contralateral heel-strike appeared to contribute toward the reduced step width for a better adjustment of the medio-lateral motion of the body's center of mass in order to maintain stability. At the hip, increased abductor moments may help to increase the pelvis stability and prevent excessive loading at the knee, and reduced internal rotator moments may reduce the torsional loading at the hip. At the knee, reduced ranges of flexion-extension and adduction-abduction motions may increase its stability. At the ankle, increased external rotation angles, together with increased pronator and external rotator moments through increased ground reaction force, may enhance the ankle stability. The current results identified the changes in the kinematics and kinetics of the lower extremities in females after long-term use of high-heeled shoes, providing a basis for future development of training programs and design of new high-heeled shoes to help those who have higher risks of falling and injuries during high-heeled gait.

scholarly journals Joint Torque and Mechanical Power of Lower Extremity and Its Relevance to Hamstring Strain during Sprint Running

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Yunjian Zhong ◽  
Weijie Fu ◽  
Shutao Wei ◽  
Qing Li ◽  
Yu Liu
Keyword(s):  
Lower Extremity ◽  
Stance Phase ◽  
Swing Phase ◽  
Joint Torque ◽  
Mechanical Power ◽  
Movement Direction ◽  
Joint Torques ◽  
Sprint Running ◽  
Lower Extremity Muscle ◽  
Muscle Groups

The aim of this study was to quantify the contributions of lower extremity joint torques and the mechanical power of lower extremity muscle groups to further elucidate the loadings on hamstring and the mechanics of its injury. Eight national-level male sprinters performed maximum-velocity sprint running on a synthetic track. The 3D kinematic data and ground reaction force (GRF) were collected synchronously. Intersegmental dynamics approach was used to analyze the lower extremity joint torques and power changes in the lower extremity joint muscle groups. During sprinting, the GRF during the stance phase and the motion-dependent torques (MDT) during the swing phase had a major effect on the lower extremity movements and muscle groups. Specifically, during the stance phase, torque produced and work performed by the hip and knee muscles were generally used to counteract the GRF. During the swing phase, the role of the muscle torque changed to mainly counteract the effect of MDT to control the movement direction of the lower extremity. Meanwhile, during the initial stance and late swing phases, the passive torques, namely, the ground reaction torques and MDT produced by the GRF and the inertial movement of the segments of the lower extremity, applied greater stress to the hamstring muscles.

scholarly journals Effects of Lower Extremity Muscle Fatigue on Knee Loading During a Forward Drop Jump to a Vertical Jump in Female Athletes

2020 ◽  
Vol 72 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Tzu Lin Wong ◽  
Chen Fu Huang ◽  
Po Chieh Chen
Keyword(s):  
Muscle Fatigue ◽  
Energy Absorption ◽  
Female Athletes ◽  
Inverse Dynamics ◽  
Cruciate Ligament ◽  
Vertical Jump ◽  
Reaction Force ◽  
Drop Jump ◽  
Shear Forces ◽  
Lower Extremity Muscle

AbstractThe aim of this study was to examine changes in the kinematic and kinetic parameters of female athletes performing a forward drop jump to a vertical jump under muscle fatigue condition. Twelve female college athletes performed a forward drop jump to a vertical jump with and without muscle fatigue conditions. A motion capture system and two AMTI force plates were used to synchronously collect kinematic and kinetic data. Inverse dynamics were implemented to calculate the participant’s joint loading, joint moment, and energy absorption. A paired sample t-test was used to compare statistical differences between pre-fatigue and post-fatigue conditions (α = .05). The forward trunk lean angle at initial foot contact, as well as the knee range of motion, total negative work and energy absorption contribution of the knee joint during the landing phase were significantly decreased under post-fatigue condition. The increased peak vertical ground reaction force and peak tibial anterior shear forces were also found under post-fatigue condition. These results indicated that muscle fatigue caused participants to change their original landing posture into stiff landing posture and decrease the energy absorption ability, which increased the tibial anterior shear forces. Therefore, female athletes should appropriately increase the knee flexion angle under muscle fatigue condition to reduce the risk of anterior cruciate ligament injuries.

Initial balance in human standing postures: Roles of the joint mechanisms

2018 ◽  
Vol 232 (12) ◽  
pp. 1255-1260 ◽  
Author(s):  
Mohammed N Ashtiani ◽  
Mahmood-reza Azghani ◽  
Mohamad Parnianpour
Keyword(s):  
Inverse Dynamics ◽  
Muscular Activity ◽  
Biomechanical Model ◽  
Lower Limbs ◽  
Stable Set ◽  
Joint Angles ◽  
Lower Extremity Muscle ◽  
Ankle Muscles ◽  
Muscle Groups ◽  
Dynamics Method

The static initial postures of standing before applying perturbations may affect the maintenance of postural balance. The goal of this article was to find the stable set of postures and then determine the roles of joint mechanisms. The set of posture was defined in a biomechanical model based on three joint angles of the lower limbs. Optimized inverse dynamics method was used to solve for muscle forces in a precise model of the human musculoskeletal system posed in 4096 static sets of posture using AnyBody software. Results showed that the overall body muscular activity in standing is reduced by knee flexion. Moderate knee angles between 20° and 60° provided safer postures against possible perturbations because of higher collaboration levels of the joint mechanisms. About 36% of the overall postural infeasibilities were attributed to the inability of the ankle muscles to more sustain the exerted loads. Although the roles of the joint mechanisms were closely dependent on the postures, there was no direct relation between the joint kinematics and activation levels of their supporting muscles. Lower extremity muscle groups collaborate to maintain the balance in a considerable number of static postures.

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