Effects of Hip Angles in Sagittal Plane on the Hip Abductor Force in Normal Subjects

Abstract

The purpose of this study was to examine the effects of hip angles in sagittal plane on the hip abductor force (HAF). Twelve healthy female volunteers (mean age : 20.4 ± 0.5 years, range : 20.0-21.0 years) participated in this study.
Subjects fixed their supine position with the hip joint flexed at the angles of 0゜, 10゜, 20゜, and 40゜, and fixed their prone position with the hip joint extended at the angles of 0゜ and 10゜. The maximum isometric HAFs were measured in a neutral and those six positions.
The mean (± SD) value of HAFs were 7.6 ± 2.0 kg・m at 40゜, 9.0 ± 2.0 kg・m at 20゜, 9.3 ± 1.9 kg・m at 10゜ and 9.5 ± 2.5 kg・m at 0゜ in flexion, and 9.5 ± 2.8 kg・m at 0゜, 9.6 ± 2.7 kg・m at 10゜ in extension. A multiple comparison (Tukey's HSD) was used to test the statistical significance of the mean difference in HAFs between six positions. The HAF at 40゜ in flexion was significantly lower than those at other angles. There were no significant differences in HAFs between angles from 20゜ of flexion and 10゜ of extension.
These results suggest that HAF at 40゜ flexion may mirror the force of tensor fasciae latae.