Influence of elbow flexion angle on mobilization of the proximal radio-ulnar joint: a motion analysis using cadaver specimens

The purpose of this study was to determine the most effective elbow joint flexion angle for mobilization of the proximal radio-ulnar joint. Five fresh-frozen cadaveric elbows were used to measure displacement of the radial head in the antero-medial and postero-lateral directions by traction force of 2kgf and 4kgf, respectively. Simulation of the gliding of the proximal radio-ulnar joint was performed at four elbow flexion angles (0 degrees , 30 degrees , 60 degrees , 90 degrees). Data obtained from those flexion angles were compared using one-way repeated measures analysis of variance. Radial head displacement at 60 degrees and 90 degrees during antero-medial gliding were significantly greater than those at 0 degrees and 30 degrees (p<0.05) There were no significant differences in radial head displacement among four elbow flexion angles during postero-lateral gliding at 2kgf and 4kgf. Our findings suggest that proximal radio-ulnar joint mobilization in the antero-medial direction can be performed effectively at 60 degrees and 90 degrees elbow flexion.