Article

OBJECTIVE: To examine the test-retest reliability and quantify the minimal
detectable change (MDC) in quadriceps strength and voluntary activation in
patients with knee osteoarthritis (OA). DESIGN: Repeated measures over a 1-week
interval. SETTING: Tertiary care center. PARTICIPANTS: A convenience sample of
patients (N=20) diagnosed with knee OA. INTERVENTION: Isokinetic and isometric
quadriceps strength testing and voluntary quadriceps activation testing using
interpolated twitch technique. MAIN OUTCOME MEASURES: Peak isokinetic and
isometric knee extension torque (Nm) and percentage of voluntary quadriceps
activation (%). RESULTS: The mean differences with 95% confidence intervals
between the 2 test sessions for quadriceps isokinetic strength, isometric
strength, and percent of voluntary activation were -4.34Nm (-14.01 to 5.34Nm),
1.56Nm (-5.56 to 8.68Nm), and 1.34% (-.53 to 3.22%), respectively. The intraclass
correlation coefficients for all measures ranged from .93 to .98. The standard
errors of measurement (SEMs) for quadriceps isokinetic and isometric strength
were 14.57Nm and 10.76Nm, respectively. The SEM for percentage of voluntary
activation was 2.84%. Based on these values, the MDCs were 33.90Nm, 25.02Nm, and
6.60% for quadriceps isokinetic strength, isometric strength, and percentage of
voluntary activation, respectively. CONCLUSIONS: Maximal quadriceps isokinetic
strength, isometric strength, and percentage of voluntary activation measures
demonstrate excellent test-retest reliability in patients with knee OA. In
addition to research applications, the present findings suggest these measures
are appropriate for use when evaluating change in neuromuscular function of the
quadriceps in individual patients.

Langue : ANGLAIS