TIBIO-FEMORAL JOINT FORCES DURING THE LANDING PHASE OF DIFFERENT TYPES OF VERTICAL JUMP

Abstract

The purpose of this study was to compare the tibio-femoral contact forces during the landing phases of 8 different types of vertical jump (squat, countermovement, hop approach and drop jumps each with and without the use of arms). Data were collected from eight males and eight females. Two S-VHS camcorders and a force platform were used to obtain the 3-D kinematics and kinetics of the knee joint. Activities of selected muscles spanning the knee joint were monitored using surface electromyographic (EMG) techniques. The EMG-assisted optimization model was used to estimate the tibio-femoral joint forces. The peak compressive contact forces ranged from 3-5 body weight (SW) and from 2.5-3.7 SW for the males and females, respectively. These loads seldom fell within the range that is considered to be damaging to the cartilage at the knee.