THE BIOMECHANICS OF THE KNEE DURING THE PARACHUTE LANDING FALL

Because anterior knee pain syndrome is common in young paratroopers, w e studied the role of the extensor mechanism in deceleration during th e parachute landing fall (PLF) and the extent of knee flexion resultin g from use of proper and variant landing styles. The subjects were nov ice paratroopers. Data were gathered by electromyography and by cinema tography. At impact, a period of myoelectric silence was found that in creased during training. Knee flexion angles varied from 130 degrees i n the proper PLF to a low of 110 degrees in the toes-knees-nose PLF an d to a high of 160 degrees in the hypergenuflexion PLF. The improper P LFs had a duration of deceleration shorter than that of a proper PLF, with maximal knee flexion occurring later in the landing act. Our resu lts give direction to more specific lower-body training.