BIOMECHANICAL GAIT ALTERATIONS INDEPENDENT OF SPEED IN THE HEALTHY ELDERLY - EVIDENCE FOR SPECIFIC LIMITING IMPAIRMENTS

Objectives: It is not known whether changes in the biomechanics of eld erly gait are related to aging per se, or to reduced walking speed in this population, The goals of the present study were to identify speci fic biomechanical changes, independent of speed, that might impair gai t performance in healthy older people by identifying age-associated ch anges in the biomechanics of gait, and to determine which of these cha nges persist at increased walking speed. Design: Stereophotogrammetric and force platform data were collected, Differences in peak joint mot ion (kinematic) and joint moment and power (kinetic) values between he althy young and elderly subjects at comfortable and increased walking speed were measured. Setting: A gait laboratory. Subjects: Thirty-one healthy elderly (age 65 to 84 years) and 31 healthy young adult subjec ts (age 18 to 36 years), all without known neurologic, musculoskeletal , cardiac, or pulmonary problems. Main Outcome Measures: All major pea k kinematic and kinetic variables during the gait cycle, Results: Seve ral kinematic and kinetic differences between young and elderly adults were found that did not persist when walking speed was increased, Dif ferences that persisted at both comfortable and fast walking speeds we re reduced peak hip extension, increased anterior pelvic tilt, and red uced ankle plantarflexion and ankle power generation, Conclusion: Gait performance in the elderly may be limited by both subtle hip flexion contracture and ankle plantarflexor concentric weakness. Results of th e current study should motivate future experimental trials of specific hip flexor stretching and ankle plantarflexor concentric strengthenin g exercises to preserve and potentially improve walking performance in the elderly. (C) 1998 by the American Congress of Rehabilitation Medi cine and the American Academy of Physical Medicine and Rehabilitation.