GAIT KINEMATICS AND VARIABILITY DURING NORMAL AND UNWEIGHTED TREADMILL RUNNING

The biomechanics of running in unusual environments has received little attention. Hence the aim was to compare normal to unweighted at 40% of bodyweight treadmill running. Kinematic data were recorded for six participants running at 3.35 m/s. The stride frequency during unweighted was less than normal treadmill running (67 ± 10 v 83 ± 5 strides/min; p = 0.03). Particularly during the stance phase, participants demonstrated less knee flexion-extension and ankle dorsi-plantar flexion angular motion. Participants also demonstrated greater within- and between-participant variability during unweighted than normal treadmill running (e.g. left knee angle SD of 1.7 ± 0.2° v 3.1 ± 2.1°; p = 0.03). Unweighted treadmill running produces gait kinematics with less movement and with greater variability, which may have implications for training and rehabilitative uses