Article

Quadriceps femoris muscle strengthening is a common rehabilitation
exercise for knee osteoarthritis (OA). More information is needed to determine
whether targeting muscle power is a useful adjunct to strengthening for people
with knee OA. The purpose of this study was to identify the predictive
ability of knee extensor strength and knee extensor power in the performance of
physical tasks in adults with knee OA. DESIGN: This study used a cross-sectional
design. METHODS: Fifty-five participants with clinical knee OA were included (43
women; mean [SD] age=60.9 [6.9] years). Dependent variables were: timed stair
ascent, timed stair descent, and the Six-Minute Walk Test (6MWT). Independent
variables were: peak knee extensor strength and mean peak knee extensor power.
Covariates were: age, body mass index, and self-efficacy. Multiple regression
analyses were run for each dependent variable with just covariates, then a second
model including strength, and then a third model including power. The R(2) values
were compared between models. RESULTS: Power explained greater variance than
strength in all models. Over and above the covariates, power explained an
additional 6% of the variance in the 6MWT, increasing the R(2) value from .33 to
.39; 8% in the stair ascent test, increasing the R(2) value from .52 to .60; and
3% in the stair descent test, increasing the R(2) value from .44 to .47.
LIMITATIONS: The sample demonstrated very good mobility and muscle function
scores and may not be indicative of those with severe knee OA. CONCLUSIONS: In
adults with knee OA, knee extensor power was a stronger determinant of walking
and stair performance when compared with knee extensor strength. Clinicians
should consider these results when advising patients on exercise to maintain or
improve mobility.
CI - (c) 2015 American Physical Therapy Association.

Langue : ANGLAIS