Article

This study investigated the effect of both walking speed and external ankle load
on the kinetic patterns of treadmill walking in preadolescents with and without
Down syndrome (DS). Ten preadolescents with DS and ten age- and gender-matched
children with typical development (TD) participated in this study. We manipulated
two treadmill speeds and two external ankle loads. Treadmill speeds were equal to
75% and 100% of the preferred overground walking speed. Two load conditions were
with and without external ankle load which was equal to 2% of body weight on each
side. We used an instrumented treadmill to collect vertical ground reaction force
(GRF). Both timing and magnitude of peak GRFs, the loading and unloading rates,
and various impulses were calculated from the GRF data. The results show that the
DS group produced a shorter duration of propulsion, a lower FZ2 (second peak GRF)
and vertical propulsive impulse, a higher loading rate and a lower unloading rate
than the TD group. At a faster treadmill speed the DS group increased the
duration of propulsion, the unloading rate and the vertical propulsive impulse,
but reduced the magnitude of FZ2. External ankle load helped the DS group
increase FZ2 and vertical propulsive impulse and might facilitate the push off
and the initiation of leg swing during treadmill walking. External ankle load may
therefore be included in the future physical intervention and exercise programs
for the DS group to strengthen leg muscles and develop more efficient push off
during locomotion.
CI - Published by Elsevier B.V.

Langue : ANGLAIS