Kinetic analysis of downward step posture according to the foothold heights and visual information blockage in cargo truck

Abstract

The study was undertaken to compare and analyze kinetic variables during downward foot-on according to the foothold heights under inter-rupted-visual information on 25-t cargo truck. Skilled adult male drivers (n=10) engaged in cargo truck driving over 1 year participated in the experiment. The results obtained from cinematographic and ground re-action force data during downward foot-on as follows; First, leg stiff-ness, peak vertical force (PVF) and loading rate showed significant dif-ference as an increase of foothold heights, that is, interrupted-visual in-formation showed greater impulse force than as was not. Second, vari-ables of center of pressure (COP) with interrupted-visual information did not showed difference, but anterior-posterior COP and COP area showed an increasing tendency as an increase of foothold heights. Third, dynamic posture stability index (overall, medial-lateral, anteri-or-posterior, and vertical) showed significant difference as an increase of foothold height, that is, interrupted-visual information showed lower index than as was not. Therefore it will be possible to control success-fully the leg stiffness, loading rate, and PVF when preparing an estimate for air phase time and impulse force through habitual cognition and confirmation at landing during downward foot-on from cargo truck. Identifying these potential differences may enable clinicians to assess type of injury and design exercise rehabilitation protocols specific.