Is triceps hypertrophy associated with ulnar nerve luxation?

INTRODUCTION

The mechanism of ulnar nerve luxation is unclear, but the triceps brachii muscle may be a contributing factor. Therefore, we explored whether hypertrophy of the triceps brachii muscle is more frequently accompanied by nerve luxation.

METHODS

In this investigation we used a cross-sectional design to study a group of amateur bodybuilders (n = 31) in a comparison with a group of age-matched healthy controls (n = 31). Triceps hypertrophy was determined clinically and sonographically. The position of the ulnar nerve in relation to the medial epicondyle was classified according to a graded (0-4) scale.

RESULTS

In full flexion of 62 hypertrophic arms, 22 (35.5%) revealed subluxation and 27 (43.5%) complete luxation. In the controls, 21 (33.9%) demonstrated subluxation and 10 (16.1%) complete luxation.

DISCUSSION: The higher frequency of ulnar nerve luxation in arms with hypertrophic triceps indicates that triceps muscle mass may be a factor contributing to ulnar nerve luxation. Muscle Nerve 58: 523-527, 2018.