The Kinematics and Kinetics Analysis of the Lower Extremity in the Landing Phase of a Stop-jump Task

Abstract

Large number of studies showed that landing with great impact forces may be a risk factor for knee injuries. The purpose of this study was to illustrate the different landing loads to lower extremity of both genders and examine the relationships among selected lower extremity kinematics and kinetics during the landing of a stop-jump task. A total of 35 male and 35 female healthy subjects were recruited in this study. Each subject executed five experiment actions. Lower extremity kinematics and kinetics were synchronously acquired. The comparison of lower extremity kinematics for different genders showed significant difference. The knee and hip maximum flexion angle, peak ground reaction force and peak knee extension moment have significantly decreased during the landing of the stop-jump task among the female subjects. The hip flexion angle at the initial foot contact phase showed significant correlation with peak ground reaction force during landing of the stop-jump task (r=-0.927, p<0.001). The knee flexion angle at the initial foot contact phase had significant correlation with peak ground reaction force and vertical ground reaction forces during landing of the stop-jump task (r=-0.908, p<0.001; r=0.812, P=0.002). A large hip and knee flexion angles at the initial foot contact with the ground did not necessarily reduce the impact force during landing, but active hip and knee flexion motions did. The hip and knee flexion motion of landing was an important technical factor that affects anterior cruciate ligament (ACL) loading during the landing of the stop-jump task.

Correlations between sagittal plane kinematics and landing impact force during single-leg lateral jump-landings

“…A power analysis for a regression model based on the kinematic and GRF data from the study of Yin et al. 16 ) indicated that 20 participants would be necessary to attain an a priori power of 0.80. Therefore, 20 healthy male collegiate athletes were recruited.…”

Is hamstrings-to-quadriceps torque ratio useful for predicting anterior cruciate ligament and hamstring injuries? A systematic and critical review

“… 7 In the included studies, isokinetic testing angular velocities ranged from 60°/s to 300°/s ( Table 1 ), which are lower than those developed during fast sport movements, such as fast kicking (∼550°/s–1720°/s, 57 sprinting (∼500°/s–800°/s), 58 or landing (∼78°/s–570°/s). 59 , 60 This may also explain the observation that angular velocity does not influence the association of H:Q ratio with injury ( Table 2 ). For this reason, evaluation of the conventional or functional H:Q at a slow angular velocity, such as 60°/s, is recommended.…”

Nonlinear System Stability and Behavioral Analysis for Effective Implementation of Artificial Lower Limb

“…where, λ = eigen value, I = Identity matrix. Suppose X = A − λI Now, det(X) = λ 2 − 20λ − 6.6354 (29) det(X) is called the characteristic equation of the matrix A. Since the matrix A − λI is singular, det(X) = 0.…”

“…Forward dynamics [29] is the connection between the forces applied on a robotic mechanism and the produced accelerations, which is presented in Figure 1. Robot dynamics [30] is the application of rigid-body dynamics to robots.…”