Article

The use of functional knee braces for returning to sports or during
demanding activities following anterior cruciate ligament rupture is common; yet
despite being commonly prescribed, its mechanism of action remains unknown.
OBJECTIVES: To examine the effect of functional knee braces on mean muscle
activity when performing lunge exercises. STUDY DESIGN: Pre-/post-test
(within-subject research design). METHODS: A total of 10 male participants with
unilateral isolated anterior cruciate ligament deficiency participated.
Electromyographic activities of six muscles around the knee were recorded during
lunge exercises, with and without wearing a custom functional knee brace. The
lunge cycle movement was subdivided into three phases: eccentric, isometric, and
concentric. RESULTS: The quadriceps and hamstrings were no different in the
braced and unbraced conditions. When braced, the mean amplitude of the medial
gastrocnemius was significantly lower throughout the whole movement (p = 0.01)
and during the concentric (p = 0.006) and eccentric (p = 0.028) phases, but not
within the isometric phase. The lateral gastrocnemius was found to have lower
mean amplitude in the isometric phase (p = 0.044). CONCLUSION: With its origin on
the medial femoral condyle, perhaps reduced medial gastrocnemius activity may
better guide knee rotation and assist the joint achieving a healthier kinematic
pattern. CLINICAL RELEVANCE: Lower medial gastrocnemius activity may facilitate
lower medial compartment contact pressure, for which greater loading is known to
increase the risk of osteoarthritis in anterior cruciate ligament-deficient
(ACLD) knees. However, further research is needed.
CI - (c) The International Society for Prosthetics and Orthotics 2014.

Langue : ANGLAIS