Normal Adult Hip Range of Motion Focusingon Hip Flexion

Kim, Keun Woo; Lee, Tae Hoon; Nam, Woo Dong; Rhyu, Kee Hyung

Abstract

PURPOSE: We performed this study to ascertain the range of hip motion during the activities of daily living in Koreans and determine the value of the clinical measurements.
MATERIALS AND METHODS
Twenty-one volunteers were enrolled in this study. The hip range of motion was measured with three-dimensional CT and fluoroscopy of the hip in the supine, sitting cross-legged and squatting position. Hip flexion and extension in various conditions were also measured. The reference lines were defined in the pelvic bone.
RESULTS
The supine hip reflected the anatomic structure of the proximal femur rather than 0 degree. Symmetrical 114.1 degrees of flexion and 41.0 degrees of external rotation were observed in the sitting cross-legged position. The sum of the abductions was 70.4 degrees. In the squatting position, the measured hip flexion was 87.4 degrees. The hip flexion increased when hip abduction was combined. An average hip extension of 17.0 degrees was noted during the Thomas test.
CONCLUSION
More than 120 degrees of hip flexion does not occur in neutral rotation and abduction. More than 100 degrees of hip flexion is observed only with a hip abduction. A large amount of spinal movements appears to be needed for both squatting and sitting cross-legged positions. Less than 17 degrees of measured flexion contracture in the Thomas test means an extension block rather than a real flexion contracture.