Isokinetic assessment of hip muscle concentric strength in normal subjects: A reproducibility study

The purpose of this study was to assess hip muscle performance in the three anatomical planes and to assess the reproducibility of measurements using isokinetic dynamometry. Twenty-eight symptom free amateur sportsmen students (I I females, 17 males), performed three consecutive isokinetic evaluations of both hips at 60 and 120 degrees/s. Nine male subjects performed a test-retest protocol. Reproducibility was reported using different statistical methods such as intraclass correlation coefficients, mean difference, standard error and 95% confidence intervals. Compared to the women's PT, men scored significantly higher in all velocities with the generally expected torque-velocity relationships. No dominance effect was noted. Significant differences between agonist and antagonist muscle performance were also indicated. The agonist/antagonist ratios ranged 0.74-1.48 and were significantly influenced by velocity with a significant inter-group difference at 120 degrees/s. Results based on the test-retest paradigm indicate caution in the interpretation of the peak torque (PT).