Article

Selecting a specific foot placement strategy to perform walking maneuvers
requires the management of several competing factors, including: maintaining
stability, positioning oneself to actively generate impulses, and minimizing
mechanical energy requirements. These requirements are unlikely to be
independent. Our purpose was to determine the impact of lateral foot placement on
stability, maneuverability, and energetics during walking maneuvers. Ten
able-bodied adults performed laterally-directed walking maneuvers. Mediolateral
placement of the "Push-off" foot during the maneuvers was varied, ranging from a
cross-over step to a side-step. We hypothesized that as mediolateral foot
placement became wider, passive stability in the direction of the maneuver, the
lateral impulse generated to create the maneuver, and mechanical energy cost
would all increase. We also hypothesized that subjects would prefer an
intermediate step width reflective of trade-offs between stability vs. both
maneuverability and energy. In support of our first hypothesis, we found that as
Push-off step width increased, lateral margin of stability, peak lateral impulse,
and total joint work all increased. In support of our second hypothesis, we found
that when subjects had no restrictions on their mediolateral foot placement, they
chose a foot placement between the two extreme positions. We found a significant
relationship (p<0.05) between lateral margin of stability and peak lateral
impulse (r=0.773), indicating a trade-off between passive stability and the force
input required to maneuver. These findings suggest that during anticipated
maneuvers people select foot placement strategies that balance competing costs to
maintain stability, actively generate impulses, and minimize mechanical energy
costs.
CI - Published by Elsevier B.V.

Langue : ANGLAIS