Article

The purpose of this study was to assess the ankle, knee, and hip joint
contributions to the total support moment (TSM) and the activation patterns of
muscles in the lower leg in patients after total knee arthroplasty (TKA) and
healthy older adults during the step up and over task.
Moreover, the relationship
between quadriceps strength and knee contribution to TSM was measured. Twenty
patients six-months after TKA and twenty healthy controls were recruited for this
study. Motion and surface electromyographic (EMG) analyses were performed during
a step up and over task. Biomechanics and EMG variables were compared between
groups using ANCOVA models with movement speed as covariate. Patients after TKA
had reduced contribution to the TSM from the knee joint, and greater contribution
from the hip and ankle joints, possibly to compensate for the reduced
contribution at the knee. No consistent differences of EMG activation or
co-contraction were found between groups. Patients with stronger quadriceps had
significantly higher knee contribution to TSM during the lowering phase of the
task. The results of this study suggest that patients after TKA may use
compensatory strategies at the hip and ankle joints to safely perform the step up
and over task. Patients may rely on the force generating ability of the
quadriceps during the lowering phase as they are not able to compensate with
other joints of the lower extremity during this phase of the task.
CI - Copyright (c) 2016 Elsevier B.V. All rights reserved.

Langue : ANGLAIS