Test-retest reliability of isometric knee extension muscle strength measurement using a hand-held dynamometer and a belt: Study of hemiplegic patients

Abstract

[Purpose] The purpose of this research was to study the test-retest reliability of three continuous sets of measurements of isometric knee extension muscle strength of hemiplegic patients, using a handheld dynamometer (HHD) and a belt. [Subjects] The subjects were 26 hospitalized hemiplegic patients (12 men, 14 women) with an average age of 62.4 years. [Method] The subjects sat on a mat table, and three sets of measurements were taken, at intervals of 30 seconds, of isometric knee extension muscle strength with the knee joint at a flexion angle of 90 degrees using an HHD and a belt. The measurements were also taken in a second session on a different day. Reliability was examined using the intraclass correlation coefficient (ICC (1,1)) and multiple comparison as a post-hoc test of one-way variance through repeated measurement. [Results] The ICC of the measurement values taken on the same day on the paralyzed side was 0.98, while in Session 2 it was 0.99; on the non-paralyzed side, it was 0.98 in Session 1 and in Session 2 it was 0.99. On the paralyzed side, main effect was seen in Session 2; the values of the first measurement were significantly smaller than the values of the second and third measurements. And, the highest values were obtained from the third measurement. [Conclusion] The ICC results show the test-retest reliability was high in both sessions. We thought it would be sufficient for measurements to be conducted three times, taking the highest values of those three.