Trunk Compensation During Bimanual Reaching at Different Heights by Healthy and Hemiparetic Adults.
OBJECTIVE The aim of this study was to investigate the effects of age, gender, and target location upon arm reach capacity and posture. BACKGROUND The older adult population is growing in number. Their specific needs must be better understood to improve the design of work and life spaces. METHOD Thirty-eight adults, divided into four groups according to their gender and age, participated in the experiment. They were asked to reach 84 targets located in a large space defined according to their anthropometry and reach capacities. Reach capacities and postures were analyzed. RESULTS On average, older participants showed shorter maximal reach distances (by 4.8% of upper limb length) as compared with younger participants. No gender difference was found for maximum reach distance. Age also had significant effects on reach posture, especially through its interactions with target azimuth. Older participants tended to use their trunk less whenever possible. Reduced neck and trunk/seat axial rotations were observed for the older participants when the target deviated from the sagittal plane. They compensated by a greater rotation of the pelvis with respect to the seat. CONCLUSION Older people's reach capacities should be taken as references, rather than those of younger people, in order to accommodate a wider range of the population. APPLICATION These results can be used to improve the arrangement of living spaces and work spaces for older people.