Dynamics of Two-Link Musculoskeletal Chains during Fast Movements: Endpoint Force, Axial, and Shear Joint Reaction Forces

Abstract

This study provides a dynamic model for a two-link musculoskeletal chain controlled by single-joint and two-joint muscles. The chain endpoint force, and the axial and shear components of the joint reaction forces, were expressed analytically as a function of the muscle forces or torques, the chain configuration, and the link angular velocities and accelerations. The model was applied to upper-limb ballistic push movements involving transverse plane shoulder flexion and elbow extension. The numerical simulation highlights that the shoulder flexion and elbow extension angular acceleration at the initial phase of the movement, and the elbow extension angular velocity and acceleration at the later phase of the movement, induce a proportional medial deviation in the endpoint force direction. The forearm angular velocity and acceleration selectively affect the value of the axial and shear components of the shoulder reaction force, depending on the chain configuration. The same goes for the upper arm and elbow. The combined contribution of the elbow extension angular velocity and acceleration may give rise to anterior shear force acting on the humerus and axial forearm traction force as high as 300 N. This information can help optimize the performance and estimate/control of the joint loads in ballistic sport activities and power-oriented resistance exercises.

Assessment of the Efficiency of Measuring Foot and Ankle Edema with a 3D Portable Scanner

“…Also, in the field of sports, the analysis of the foot morphotypes of the athletes using this device could make it possible to improve the performance of the shoes while avoiding the most common injuries. Some of them are due to an inappropriate distribution of the volume of the shoes or a bad adaptation to the foot variations during exercise [49][50][51].…”

Assessment of Foot and Ankle Edema With a 3D Portable Scanner

“…specific construct is needed for a foot and ankle deformity such as flatfoot, recently renamed progressive collapsed foot deformity, this would also be possible [14] Also, in the field of sports, the analysis of the feet morphotypes of the athletes using this device could make it possible to improve the performances of the shoes while avoiding the most common injuries. Some of them are due to an inappropriate distribution of the volume of the shoes or a bad adaptation to the feet variations during exercise [49,50,51].…”

Cutting-Edge Research in Sports Biomechanics: From Basic Science to Applied Technology

“…Wearable sensors, motion capture systems, force plates, 3D printing, and virtual reality are just a few examples of applied technologies used in sports biomechanics. These tools provide precise measurements and data that are used to analyze and optimize human movement [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Furthermore, they enable the development of custom-fit equipment, training programs, and injury prevention strategies that are tailored to athletes' individual needs.…”

“…The authors cover a wide variety of important, innovative, and timely topics in the field. The themes include sports technology analysis [ 6 , 7 , 8 , 9 , 10 ], the mechanics of human motion [ 11 , 12 , 13 , 14 , 15 ], bionic applications and equipment design [ 16 ], and the mechanisms of sports injuries [ 12 , 13 ]. In this editorial, we will discuss the current state of sports biomechanics and the direction it is headed.…”