The Effect of Physical Factors on Grip Strength and Dexterity

This study evaluated the relationship between physical factors (age, sex, hand size and dominance, height and weight) and both grip strength and dexterity. Ninety healthy subjects without current upper extremity pathology or injuries were recruited. Anthropometric measures of the hand were taken using the NK Micrometer, grip strength using the NK Digit-Grip, and dexterity (small, medium and large subsets) was tested using the NK Dexterity Board. Univariate correlations between grip strength and subject height, hand span, width and length were significant (r=0.38-0.82). Sex (p 0.001) and hand dominance (p 0.05) were also significant predictors of grip strength. Increased age resulted in increased time in all dexterity subtests (r=0.30-0.51). Multivariate stepwise regression revealed that sex explained the majority of variance in grip strength scores (r2=0.46-0.76), with additional contribution of age and height. Dexterity was less predictable, but most related to age (r2=0.13-0.26), with sex and dominance providing some additional information. While it is relatively easy to establish that a patient has an impaired grip, caution should be taken when ascribing that label to an individual patient's performance on a dexterity test.