Effets de l'application de charges aux membres inférieurs sur le patron de marche des personnes hémiparétiques chroniques
Adding a load on the lower limb is a non evidence-based approach used by clinicians to strengthen weak muscles that are important for faster gait. This pilot study was aimed at determining changes in the gait pattern in stroke individuals walking with a load on the affected or non-affected ankle and comparing their results to those of healthy control subjects. It is supposed that a load placed on the paretic/non-dominant leg (ipsilateral load) would increase efforts (moment and power) on the paretic/non-dominant hip during the swing phase and that a load placed contralaterally would increase efforts on this hip during the stance phase, particularly on the hip abductor muscles which stabilizing the pelvis in the frontal plane.  The gait pattern of five chronic stroke participants and five healthy individuals was assessed in laboratory by ground reaction forces and infrared marker recordings. Time-distance parameters, affected/non-dominant hip and trunk kinematics (angles) as well as affected/non-dominant hip kinetics (nets moments, powers and mechanical work) were compared between three conditions (two with a load) at similar cadences using non-parametric statistical tests in both groups. Adding a load had no effect on gait speed in all participants. The load improved the swing and stance symmetry. Few changes in the sagittal plane with load were observed compared to without a load. In the frontal plane, stroke subjects showed a hip abductor moment decrease with the contralateral load while healthy controls showed an increase. Use of a dynamic or postural strategy at the trunk could explain the difference in the load effect on the hip abductor moment. These results require further investigations to assess this strength training specific to the task before recommending its use.
Biomechanics Gait Stroke Load Hip Trunk