SIT TO STAND FROM PROGRESSIVELY LOWER SEAT HEIGHTS - ALTERATIONS IN ANGULAR VELOCITY

This study investigates the influence of chair height on the dynamics of sit-to-stand for two age groups, Eleven young (25-36 years) and 10 older (61-79 years) adults participated. Subjects rose from chairs set at four heights relative to knee height, Motion was quantified using a bilateral active-marker-based motion analysis system. Subjects appea red to increase trunk flexion angular velocity to overcome mechanical difficulties of decreasing chair heights. This variable showed a main effect for chair height (P = 0.0001). Time at which knee, hip, and tru nk extension angular velocity were attained each demonstrated a chair by age interaction effect (P < 0.05), Synchrony of body segment maximu m extension angular velocities was altered for the older subjects at t he lowest chair heights, suggesting that older individuals begin to ch ange their performance as the task becomes more demanding. Relevance-S itting to standing is one of the essential physical tasks used frequen tly throughout the day. Clinicians are frequently called upon to impro ve chair rise performance for those with functional limitations. Effor ts are likely to be most successful if clinicians understand how healt hy individuals accommodate to changing conditions (such as changing ch air height) and use that information to interpret the performance of t hose with impairments and functional limitations.