Test-retest reliability of isometric and isokinetic wrist strength

Abstract

BackgroundThe isokinetic dynamometer has been considered the gold-standard measurement of muscle performance. However, the reliability for the isometric and isokinetic wrist flexor and extensor strength using the Biodex isokinetic dynamometer has not been reported to date. This study evaluated test-retest reliability of isometric and isokinetic wrist strength using the Biodex System 3 isokinetic dynamometer. MethodsThis is a test-retest reliability study. Peak concentric and isometric torque was determined of the dominant limb wrist flexor and extensor of healthy individuals using the Biodex Multi-Joint System 3 dynamometer. The participants were evaluated by the same examiner in two different sessions separated by an interval of two to seven days. Reliability was investigated using the intraclass correlation coefficient (ICC2,1), standard error of measurement (SEM) and minimum detectable difference (MDD). ResultsTwenty healthy subjects participated in the study. The ICCs for concentric and isometric torque of the wrist flexor and extensor ranged from 0.79 to 0.91, revealing excellent intra-examiner test-retest reliability; SEM ranging from 0.4 to 1.5; and MDD ranged from 1.12 Nm to 4.17 Nm. ConclusionsExcellent intra-examiner test-retest reliability was found regarding peak concentric toque of the wrist flexor and extensor at an angular velocity of 45°/s as well as isometric torque of the wrist flexor and extensor in healthy individuals measured using the Biodex System 3 isokinetic dynamometer.