Hip moments during level walking, stair climbing, and exercise in individuals aged 55 years or older

BACKGROUND AND PURPOSE: Low bone mass of the proximal femur is a risk factor for hip fractures. Exercise has been shown to reduce bone loss in older individuals; however, the exercises most likely to influence bone mass of the proximal femur have not been identified. Net moments of force at the hip provide an indication of the mechanical load on the proximal femur. The purpose of this study was to examine various exercises to determine which exercises result in the greatest magnitude and rate of change in moments of force at the hip in older individuals. SUBJECTS AND METHODS: Walking and exercise patterns were analyzed for 30 subjects (17 men, 13 women) who were 55 years of age or older (X = 65.4, SD = 6.02, range = 55-75) and who had no identified musculoskeletal or neurological impairment. Kinematic and kinetic data were obtained with an optoelectronic system and a force platform. Results. Of the exercises investigated, only ascending stairs generated peak moments higher than those obtained during level walking and only in the transverse plane. Most of the exercises generated moments and rate of change in moments with magnitudes similar to or lower than those obtained during gait. CONCLUSION AND DISCUSSION: Level walking and exercises that generated moments with magnitudes comparable to or higher than those obtained during gait could be combined in an exercise program designed to maintain or increase bone mass at the hip.