Range of motion of the wrist: implications for designing computer input devices for the elderly

Purpose : The purpose of this study was to report normative values of the a mplitude of joint wrist motions and grip strength for older age groups. Method: Volunteers, (N = 147) were divided into four age groups, 60-69, 70- 79, 80-89 and 90-years, with a total of 62 men and 85 women. Maximum range motion values were obtained for wrist flexion, extension and ulnar deviatio n. In addition, grip strength measures were obtained for each participant. Results: In general, the strength and ROM values for the oldest participant s in this study were lower than those of the younger age group (age 60 to 6 9) and significantly lower than those published for subjects between 25 and 54 years of age. Furthermore, across all age groups males were significant ly stronger than females. However, females tended to have greater ROM than males, particularly for wrist extension and ulnar deviations. Joint ROM and grip strength declined significantly with age for both males and females. Comparisons with published data for younger subjects (age 25-35) indicate t hat a 60-69 year old male, will on average experience a decline in wrist fl exion, extension and ulnar deviation of 12%, 41%, and 22% respectively. By age 90, an individual may be expected to have ROM values that are only simi lar to 60% of an average 30 year old individual. Conclusion: The results suggest that the ageing population (particularly me n) may face greater difficulty using an input device such as a mouse that r elies on motions of the wrist. In addition, the reduced ROM of the wrist ma y put the elderly at greater risk of developing cumulative trauma disorders . The implications of these findings for the design of input devices are di scussed.