Article

OBJECTIVE: To assess the reliability of knee extensor and flexor muscle strength
measurements in persons with late effects of polio.
DESIGN: A test-retest
reliability study. SUBJECTS: Thirty men and women (mean age 63 (standard
deviation 6.4) years) with verified late effects of polio.
METHODS: Knee extensor
and flexor muscle strength in both lower limbs were measured twice 7 days apart
using a Biodex dynamometer (isokinetic concentric contractions at 60 degrees /sec
and isometric contractions with knee flexion angle 90 degrees) and a Leg
Extension/Curl Rehab exercise machine with pneumatic resistance (HUR) (isotonic
contractions). Reliability was assessed with the intraclass correlation
coefficient (ICC1,1), the mean difference between the test sessions (d) together
with the 95% confidence intervals for d, the standard error of measurement (SEM
and SEM%), the smallest real difference (SRD and SRD%) and Bland-Altman graphs.
RESULTS: Test-retest agreements were high, (ICC1,1 0.93-0.99) and measurement
errors generally small. The SEM% was 4-14% and the SRD% 11-39%, with the highest
values for the isokinetic measurements. CONCLUSION: Knee muscle strength can be
measured reliably and can be used to detect real changes after an intervention
for a group of persons with late effects of polio, whereas the values may be too
high for single individuals or to detect smaller short-term changes over time for
a group of individuals.

Langue : ANGLAIS