Intra- and inter-rater reliability of the rate of force development of hip abductor muscles measured by hand-held dynamometer

ABSTRACT

The aim of this study was to clarify the intra- and inter-rater reliability of the rate of force development in hip abductor muscle force measurements using a hand-held dynamometer. Thirty healthy adults were separately assessed by two independent raters on two separate days. Rate of force development was calculated from the slope of the force-time curve that was divided into four time intervals (50, 100, 200, and 300 ms). The highest values of the three trials were used for statistical analysis. The intra-class correlation coefficient with a 95% confidence interval, standard error of measurement, and minimal detectable change at the 95% confidence level were calculated for each interval. For assessment of systematic error, Bland-Altman analysis was used. The results indicated that intra- and inter-rater reliability of the highest values at all intervals were sufficient (intra-class correlation coefficient > .7). The Bland-Altman analysis did not show systematic error in either reliability measure.

KEYWORDS:

• Hand-held dynamometer
• hip abductor muscles
• rate of force development
• reliability

Acknowledgment

The authors appreciate the staff of the Department of Rehabilitation at Kawamura Hospital for their helpful technical assistance.

Disclosure of interest

The authors report no conflicts of interest.