Effects of Elbow Flexion on the Hand-Grip Strength

The objective of this study was to explore the effects of elbow flexion on the hand-grip strength. The data were collected by trained, senior and graduate students as a required mini-project in an ergonomics course. A sample of 125 female and 222 male adults, ages 18 to 47 (22.5±3.35), body heights of 173.0±10.47cm and body weights of 73.6±16.48 kg, mostly from college student population, were tested using standardized data collection form, positioning and instructions. In this study, the grip strengths of 347 subjects were measured and recorded over a multiple number of years. Pair-wise comparisons using the Student's T-Test showed that the hand-grip strength at the elbow in the fully extended position was significantly higher than when the elbow flexed. The test also showed significantly higher grip strength in 90° flexed position than in 30°, 60° or 120° flexion. No significant differences were found in the grip strength among the 30°, 60° or 120° elbow flexed positions. Comparison of the average hand-grip strength of dominant-hand and non-dominant hand of the subjects showed a significant difference. The female subjects found to have about 41% lower grip strength than the male counterparts.