A treadmill ergometer for three-dimensional ground reaction forces measurement during walking

This report describes new treadmill ergometer designed to measure the verti cal and horizontal ground reaction forces produced by the left and right le gs during walking. It was validated by static and dynamic tests. Non linear ity was from 0.2% (left vertical force) to 1.4% (right antero-posterior for ce). The resonance frequency was from 219 (right vertical direction) to 58 Hz (left medio-lateral direction). A calibration "leg", an air jack in seri es with a strain gauge, was developed and used to produce force signals com parable to those obtained during human locomotion. The mean differences bet ween the force measured by the calibration leg and treadmill ergometer at 5 km h(-1) were 3.7 N (0.7%) for the left side and 6.5 N (1.2%) for the righ t. Measurements obtained during human walking showed that the treadmill erg ometer has considerable potential for analysing human gait. (C) 2000 Elsevi er Science Ltd. All rights reserved.