The Excursion of the Median Nerve during Nerve Gliding Exercise: An Observation with High-resolution Ultrasonography

The purpose of this study was to assess the relationship between the positioning of upper extremity and gliding distance of the median nerve during passive and active motion of the wrist and fingers. The longitudinal gliding of the medial nerve in the forearm was measured in 34 healthy subjects by ultrasonographic dynamic images. Those images were analyzed in a cross-correlation algorithm advocated by Dilley et al. (2001). In this experiment, passive extension of the wrist and fingers was applied manually by an examiner in four positions (elbow flexion and extension with forearm pronation, and elbow flexion and extension with forearm supination), two types of active finger motions (Hook and Grasp) were performed by the subjects. The distally oriented median nerve gliding ranged from 1.9 (in elbow extension with forearm pronation) to 3.0 mm (in elbow flexion with forearm supination) during passive extension of the wrist and fingers. There was a statistically significant difference in nerve gliding between the positions (p = 0.001). During active digital movement, the proximally oriented nerve gliding was observed from 0.8 (in the hook) to 1.3 mm (in the grasp). There was a significant difference in nerve gliding between the two ways of active finger motions (p = 0.001). On the basis of the data obtained from this study, it is concluded that forearm supination is the preferred position for the passive median nerve gliding exercise because of large distally oriented nerve gliding. The active digital motion with full finger grip may be an effective procedure to produce proximally oriented median nerve gliding.