S. Rietdyk et Ae. Patla, DOES THE STEP LENGTH REQUIREMENT IN THE SUBSEQUENT STEP INFLUENCE THESTRATEGIES USED FOR STEP LENGTH REGULATION IN THE CURRENT STEP, Human movement science, 13(1), 1994, pp. 109-127
A comprehensive description of the prospective gait adaptations used d
uring transient step length adjustments was achieved by examining the
kinematics, force plate kinetics and EMG simultaneously. To achieve a
single lengthened step, the runner decreased braking and increased pus
h-off during stance, and increased the reach of the swinging limb. Whe
n foot placement was also constrained in the subsequent step, the gait
parameters showed significantly different modifications in both stanc
e and swing limbs during the first step. When a short step followed th
e long step, the centre of mass was biased backwards in the first step
, allowing greater time and/or distance to reduce the linear momentum
to accomplish the subsequent short step safely. To achieve two long st
eps, the take-off velocity was increased, while the landing velocity w
as reduced because the subject was not free to compensate during the s
ubsequent step. These adaptive strategies highlight the interaction of
the task, stability and safety requirements during locomotion and ten
d to support a malleable control of human locomotion.