The effect of position and speed on ankle plantarflexion in females.

This study was undertaken to determine isokinetic plantarflexion strength at various speeds and positions on a Cybex II+ dynamometer. A second purpose of this study was to identify any relationship between calf circumference and strength. Speeds used were 0, 30, and 180 degrees /sec. Positions used were supine with 0 degrees knee extension, supine with 90 degrees knee flexion, and prone with 0 degrees knee extension. Speeds and positions are randomly ordered. Nineteen female subjects were classified as either trained (N = 9) or untrained (N = 10). Plantarflexion strength was greatest in the supine position with 0 degrees knee extension in each of the three speeds tested. The results of a two-way repeated measures analysis of variance test were significant across all speeds occurring only with the trained group at a speed of 0 degrees /sec. Further comparisons of position with other speeds were not significant. Since plantarflexion torques were higher in the supine position with 0 degrees knee extension with a speed of 30 degrees /sec, clinicians might want to use this position and speed to test ankle plantarflexion torque. The relationship between calf circumference and torque was not significant. J Orthop Sports Phys Ther 1990;12(4):153-156.