Knee extensor strength measured using a Biodex dynamometer and an adapted hand held dynamometer

Clements, S. and Samuel, D. (2014) Knee extensor strength measured using a Biodex dynamometer and an adapted hand held dynamometer. International Journal of Therapy and Rehabilitation, 21 (6), 274-278. (doi:10.12968/ijtr.2014.21.6.274).

Abstract

Background: Muscle strength is widely used as an outcome measure in rehabilitation and knee
extensor strength is an important determinant of physical function. Hand held dynamometry (HHD) is
portable and easy to use; however, reliability of HHD measurements is significantly influenced by the
strength of the tester. The present study assessed the agreement between an adapted HHD and
Biodex dynamometry while measuring knee extensor strength in young adults.

Method: Thirty participants aged 22–35 years (mean age 24.4 years; SD ± 2.5) were studied. Peak
isometric knee extensor strength of the dominant leg was measured using the Biodex dynamometer
and adapted HHD. The agreement between the maximum voluntary contractions (MVC) was
analysed using Pearson’s Correlation Coefficient, intraclass correlation (ICC) and Bland–Altman analysis.

Results: The mean peak knee extensor MVC was 191.7 Nm (± 53.6) for the Biodex dynamometer and
167.5 Nm (± 55) for the adapted HHD. The mean difference in peak knee extensor strength measured
using the adapted HHD was 24.1 Nm (± 30.3) lower when compared to the Biodex. However, there
was good correlation between the two measures (r=0.796, ICC (3, 1): peak torque=0.796; average of
three trials=0.808) and Bland–Altman plots confirmed good agreement.

Conclusions: The knee strength measurements were not influenced by examiner strength and results
obtained using the adapted HDD were comparable to that using the Biodex; however, the absolute
knee extensor strength obtained using the adapted HHD was generally lower.

This record has no associated files available for download.

Contributors

Author: D. Samuel

Download statistics