Head and pelvic movements during a dynamic reaching task in sitting: implications for physical therapists.

Abstract

To describe the distance reached, speed, and movement of the head and pelvis of healthy volunteers; to describe any influence of age on these variables; and to compare healthy volunteers and subjects with hemiplegia while performing a seated reaching task. Age-matched, case-control study. Gait laboratory in a general hospital. A convenience sample of 53 healthy volunteers (30 women; 23 men; mean age, 57yr; range, 30-79yr) and 5 subjects with hemiplegia (2 women, 3 men; mean age, 65yr; range, 60-78yr) were recruited within 6 weeks poststroke. Participants sat on a bench with feet supported and reached laterally as far as they could without falling. The speed, distance reached, and angular movements of the head and pelvis were recorded by using the 3-dimensional movement analysis system. A significant age-related reduction in the distance reached (p < .001), velocity of the movement (p =.000), and pelvic tilt used (p < .01) was found among healthy volunteers. Comparison of data from healthy volunteers and subjects with hemiplegia showed a significant reduction in the angular movements of the heads of subjects with hemiplegia. The findings suggest conservation of movement with increasing age and stroke. This movement reduction could have negative effects on a subject's ability to make postural changes in response to disturbance and activity. Such information may assist therapists to gain insight into the nature of balance deficits and the adaptive behavior that could result.