Article

ACL reconstruction is recommended to improve function in subjects
with ligament injuries. However, after surgery, some individuals are not able to
return to their pre-injury functional level.
The mechanisms related to this
incapacity are not well understood. STUDY DESIGN: Cross-sectional study. METHODS: Co-contraction levels were assessed in individuals who returned to their
pre-injury functional level and in 10 individuals who were not able to return to
full activity after unilateral ACL reconstruction. Electromyography of the vastus
lateralis and biceps femoris muscles before and after sudden perturbations
applied during the stance phase of walking was used to calculate co-contraction.
RESULTS: The involved limb had lower co-contraction pre-perturbation than the
non-involved limb in both groups (p=0.049). The co-contraction level
post-perturbation was significantly higher in the limited return group than in
the full return group (p=0.03). CONCLUSION: Decreased co-contraction in the
involved limb before perturbation may be caused by sensorial changes resulting
from surgery or injury. Increased co-contraction levels observed in the limited
return group after perturbation may be a compensatory mechanism to make up for
possible decreased intrinsic stability of the knee joint. CLINICAL RELEVANCE:
Increased co-contraction after perturbation does not contribute to knee stability.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS