The Trunk-pelvis-femur Rhythm during Unilateral Hip Flexion Movement in Young and Elderly Subjects

Abstract

Purpose: The purpose of this study was to identify the relationship between the movements of the pelvis, trunk, and thigh during unilateral hip flexion in the standing position and the aged-related effects of this relationship.

Method: The study contained two groups with 10 male subjects in each: a young group (mean age 24.3 years, SD 4.5 years), and an elderly group (mean age 72.2 years, SD 4.1 years). Three-dimensional motion analysis of the trunk, pelvic and lower extremities and ground reaction force measurements were performed during hip flexion in the standing position: the segmental positions, joint angles, and center of pressure were calculated. The relationship among each parameter was analyzed.

Result: Pelvic posterior tilt, lateral tilt and trunk flexion movements increased linearly with hip flexion, irrespective of age. Aging effects were found in pelvic posterior tilt and trunk flexion movements, indicating smaller movements in the elderly group than in the young group. Standing posture did not show any age-related effects.

Conclusion: These results suggest the significance of the relationship between age and the movements of the pelvis, trunk and hip flexion during hip flexion tasks in the standing position and the necessity to analyze trunk and pelvic movements while evaluating motor tasks with hip flexion.