Reduced hip extension during walking: healthy elderly and fallers versus young adults.

OBJECTIVES To test the hypothesis that reduced hip extension range during walking, representing a limiting impairment of hip tightness, is a consistent dynamic finding that (1) occurs with increased age and (2) is exaggerated in elderly people who fall. DESIGN Using a 3-dimensional optoelectronic motion analysis system, we compared full sagittal plane kinematic (lower extremity joint motion, pelvic motion) data during walking between elderly and young adults and between elderly fallers and nonfallers. Comparisons were also performed between comfortable and fast walking speeds within each elderly group. SETTING A gait laboratory. PARTICIPANTS Twenty-three healthy elderly subjects, 16 elderly fallers (otherwise healthy elderly subjects with a history of recurrent falls), and 30 healthy young adult subjects. MAIN OUTCOME MEASURES All major peak joint angle and pelvic position values. RESULTS Peak hip extension was the only leg joint parameter measured during walking that was both significantly lower in elderly nonfallers and fallers than in young adult subjects and was even lower in elderly fallers compared with nonfallers (all p <.05). Peak hip extension +/- standard deviation during comfortable walking speed averaged 20.4 degrees +/- 4.0 degrees for young adults, 14.3 degrees +/- 4.4 degrees for elderly nonfallers, and 11.1 degrees +/- 4.8 degrees for elderly fallers. Peak hip extension did not significantly improve when elderly subjects walked fast. CONCLUSION An isolated and consistent reduction in hip extension during walking in the elderly, which is exaggerated in fallers, implies the presence of functionally significant hip tightness, which may limit walking performance. Overcoming hip tightness with specific stretching exercises is worthy of investigation as a simple intervention to improve walking performance and to prevent falls in the elderly.