Abstract
The purpose of this study was to describe the reliabilities and determinants of isometric pronation and supination forces obtained with a hand-held dynamometer. Healthy volunteers (12 women, 12 men) were tested twice on each side on two nonconsecutive days by each of two testers. Reliabilities of pronation and supination forces between trials. testers, and days were described separately by mean percentage differences. Values ranged from 0.4 to 6.8%. Intraclass correlation coefficients (Ices) were derived using the mean square value of repeated measures analysis of variance (ANOVA) procedures and the ICC equation (3.1). All ICC values were 0.904 or above, indicating a high degree of reliability. The extent to which gender, muscle action, and side of dominance influenced force measurements were summarized descriptively and examined by multifactorial ANOVA procedures. The results indicated female subjects generated forces that were 52.0% of those generated by male subjects. The dominant side pronation forces were 15.8% greater than those on the nondominant side, whereas supination forces were 4.3% greater on the dominant side. Overall supination forces were 6.2% greater than pronation forces. The ANOVA showed significant differences between genders and between actions, but not between sides. The results of this study of healthy subjects provide evidence of the reliability of hand-held dynamometer measurements of forearm pronation and supination farces, When used clinically. such forces should be interpreted tn regard to gender and action.