Intrarater and interrater reliability of hand held dynamometer for healthy quadriceps femoris: the effect of muscle strength

Abstract

Objective: The primary purpose of this study was to examine the intrarater and interrater reliability of hand-held dynamometry to assess Quadriceps Femoris (QF) muscle strength. The second purpose of the study was to detect the effect of muscle strength on reliability.

Method: Forty voluntary undergraduate students of physical education program (20 male, 20 female; mean age: 21,8 +/- 1,84 yr) and 50 undergraduate students of physiotherapy program (25 male, 25 female; mean age: 20,9 +/- 1,38 yr) participated in this study. Dominant side QF muscle strength was measured using by a HHD. The measurements were taken by two final year physiotherapy students on two occasions, with a week between tests. The Intraclass Correlation Coefficients (ICC) was calculated for reliability.

Results: ICC for intrarater reliability was 0.82 for the physical education students and 0.83 for the physiotherapy students. Similar results were found for interrater reliability (ICC=0.84 for the physical education students; ICC=0.83 for the physiotherapy students). On the other hand, physically active students were seen to have higher QF muscle strength compared to sedentary students (p<0.05).

Conclusion: Our study show that HHD shows excellent interrater and intrarater reliability for assessing QF muscle strength in healthy young adults. The reliability is not influenced by muscle strength.