M. Schenkman et al., SIT TO STAND FROM PROGRESSIVELY LOWER SEAT HEIGHTS - ALTERATIONS IN ANGULAR VELOCITY, Clinical biomechanics, 11(3), 1996, pp. 153-158
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.