Pelvifemoral rhythm during unilateral hip flexion in standing.

Abstract

To quantify pelvifemoral rhythm during unilateral hip flexion in standing subjects, under different degrees of resistance. Descriptive and correlational. Pelvic rotation contributes to the change in hip flexion angle while individuals are supine. Degree of contribution in standing has not been described. Pelvic and femoral motions, relative to vertical, were documented while 14 subjects performed three trials of standing unilateral hip flexion, both with and without a 4.53 kg ankle weight. Pelvic and thigh segments were marked with reflective spheres, and motion was captured by video analysis. Pelvic rotation contributed 18.1% of the change in hip flexion angle. Pelvic rotation occurred throughout the movement. Neither presence of external resistance nor direction of movement significantly changed this contribution. A strong relationship exists between pelvic rotation and hip flexion in standing subjects. Hip flexion, while standing, is a common element of many functional activities. Knowledge of the pelvic contribution increases our understanding of hip and lumbar spine motion during standing activities.