The effect of knee braces on knee joint kinematics at different exercise speeds

This study aims to investigate the influence of a new semi-rigid knee joint braces on kinematics using the Opti-knee knee joint kinematic analysis system at various exercise speeds. Twenty-four healthy young male adults were recruited for this study. Participants were randomly assessed while wearing and not wearing knee brace at four different speeds on a treadmill: normal walking (3.6 km/h), brisk walking (5.4 km/h), jogging (9 km/h), and moderate intensity running (10.8 km/h). Six degrees of freedom kinematic data from the knee joint were collected. Paired t-tests were conducted to calculate the kinematic differences. At speeds of 3.6 km/h and 5.4 km/h, wearing the knee brace led to reduced knee joint mobility in anterior-posterior translation, superior-inferior translation, internal-external rotation, and flexion-extension angles during the stance phase (P < 0.05). At 9 km/h, wearing the brace reduced knee joint internal-external rotation and flexion-extension mobility during the stance phase (P < 0.05). At 10.8 km/h, wearing the brace reduced knee joint flexion-extension mobility during the stance phase (P < 0.05). Wearing brace has significant influence on knee kinematics at four speeds, and the effect of brace varies with the speed of movement.