The Impact of Muscular Variation on the Neurodynamic Test for the Median Nerve in a Healthy Population With Langer's Axillary Arch

Abstract 

Objective

The neurodynamic test of the median nerve (ULNT1) is frequently used to assess the mechanics and physiology of the brachial plexus and median nerve. The present study looks for a positive ULNT1 in a healthy population with Langer's axillary arch (LAA) and analyzes whether LAA affects the elbow extension range of motion (EE-ROM) of the ULNT1.

Method

Of 640 volunteers screened, 26 LAA sides were finally included. Additional history taking revealed “minor symptoms” in some subjects. Minor symptoms do not qualify as a disorder because there is no interference with daily activities and no medical advice is sought. This study investigates whether the ULNT1 can (re)produce minor symptoms or abnormal responses in subjects with LAA. The EE-ROM was compared between the subjects' left and right side, and the subtraction angle—which is the effect of placing the cervical spine in contralateral lateral flexion—was compared between LAA sides and controls.

Results

Langer's axillary arch sides showed a significant increase in the occurrence of minor symptoms and positive ULNT1, but no influence was observed on the EE-ROM.

Conclusions

These findings suggest that LAA may be capable of transiently provoking the axillary neurovascular bundle. The unaffected EE-ROM may be the consequence of a vascular origin of the minor symptoms or the consequence of an ulnar nerve/medial cord response to the ULNT1.

Key Indexing Terms: Regional Anatomy, Brachial Plexus, Median Nerve, Neurovascular Syndrome, Diagnosis, Rehabilitation