Maximal power grasp and three-jaw chuck pinch force as a function of wrist position, age, and glove type

In many industries, environmental and/or safety considerations require the use of gloves in combination with awkward wrist positions for a diverse workforce. In an effort to quantify the effects of wrist position, glove type, age, gender, and dominant/non-dominant hand on power grasp and three-jaw chuck pinch force magnitudes, a study was performed. Maximal voluntary power grasp and three-jaw chuck pinch force for both the dominant and non-dominant hand were used as the dependent measures of physical capabilities. Six glove types: bare hand, thermal, knit, reinforced knit, a layered combination of thermal and knit, and a layered combination of thermal and reinforced knit were used as one of the independent variables. For each glove condition, one of five wrist positions was employed: 65° extensions, neutral, 45° flexion. Male and female subjects were selected from three age categories (20-25, 40-45, and 60-65). Five subjects within each age-gender category were tested giving a total of 30 subjects. The analysis of variance (ANOVA) for the dependent variable power grasp demonstrated that gender, glove type, hand, and wrist position had a significant impact on the magnitude of force exerted. The ANOVA on the dependent variable three-jaw pinch showed that gender, hand and wrist position were significant, as found for grasp; however, glove type was not significant for pinch. The Pearson product-moment correlation between grasp and three-jaw chuck pinch was calculated overall and calculated by significant effects. While the correlations were statistically significant, the level of correlation was not acceptable. A linear regression was performed to predict peak three-jaw chuck pinch from maximal power grasp force. As found with the correlations, a statistically significant regression was performed with a resultant unacceptable R² value.