Comparison of Wrist Motion and Grip Strength in a Normal Chinese and Caucasian Population

BACKGROUND: Anatomical and functional differences between Asian and Caucasian populations have been described and are important in treatment of wrist pathology. The purpose of this study was to establish and compare normal values in an Asian and Caucasian population. We hypothesized that a normal Asian population will have greater wrist ROM and reduced grip- strength when compared to a normal Caucasian population. METHODS: One hundred and-seventy-one normal Asian and 156 normal Caucasian wrists were evaluated. We excluded wrists with current or a history of wrist pathology including past surgery, injury or congenital malformation. We collected demographic information regarding occupation, body mass index (BMI), and previous wrist pathology. The wrist measurements included: wrist extension, flexion, radial, ulnar deviation, and grip strength. Wrists were also evaluated for a mid-carpal clunk, and scaphoid shift test. Mixed models accounted for evaluation of both hands in the same individual and for the relative contribution of different factors to the outcome measures of ROM and grip- strength. RESULTS: The two groups differed in height, BMI and the distribution of occupation. The Asian group had more flexion, less extension and similar radial/ulnar wrist deviation when compared to the Caucasian group. Ethnicity was a significant predictor of wrist joint flexion and extension significantly predicting grip- strength. Age was associated with ROM while occupation, hand side and gender were not significant factors in the mixed model. CONCLUSIONS: We found discrete differences between values in the two populations. More study of anatomical morphological patterns may explain the reason for variations in motion and grip- strength. The differences identified in this study between Asian and Caucasian populations should be taken into account when evaluating outcomes of wrist therapeutic procedures and rehabilitation in different communities.