Effect of Elbow Flexion on Supination, Pronation and Grip Strengths

ABSTRACT

OBJECTIVE: This study was designed to investigate the effect of elbow flexion on the maximal strengths of supination, pronation, and grip which are important component of hand function. METHOD: The maximal isometric strength of supination and pronation using BTE work simulator and grip strength using hand-held dynamometer were measured in thirty normal adult subjects. Maximal voluntary contraction for 5 sec was performed at the 0, 45, and 90 degrees of elbow flexion randomly. RESULTS: 1) The maximal isometric strengths of supination and pronation were significantly higher at the 0 degree, and lower at 90 degrees of elbow flexion (p<0.05). 2) The maximal grip strength at the 0 degree of elbow flexion was significantly higher than that of 45 and 90 degrees of elbow flexion (pp<0.05). CONCLUSION: The strengths of supination, pronation, and grip were affected by the elbow flexion, which were higher in the extended position of elbow. Therefore the elbow angle should be considered and individualized treatment program should be designed in hand rehabilitation to improve strength and to minimize the incidence of overuse disorder.