Grip strength: effects of testing posture and elbow position.
This study was designed to determine the effect of testing posture and elbow position on grip strength. A hand dynamometer was used to measure the grip strength of 61 subjects (26 female and 35 male) in four positions: (1) sitting with elbow in 90 degree flexion, (2) sitting with elbow in full extension, (3) standing with elbow in 90 degree flexion, and (4) standing with elbow in full extension. The four experimental conditions were randomized, and standardized instructions were followed. A two-factor (gender and treatment) repeated measures ANOVA was used to determine any significant difference in grip strength between the sexes and the experimental (treatment) conditions. The result of the ANOVA revealed a significant F-ratio for gender and treatment main effects. Scheffé post hoc analysis revealed that males had higher (p less than .01) grip strength than females at all the testing postures and elbow joint angles, and that there was a significant (p less than .05) difference between the grip strength measured in subjects sitting with the elbow in 90 degree flexion and standing with the elbow in full extension. The findings suggest the need for clinicians to maintain standard testing conditions while measuring grip strength.