Upper limb tension test - a cadaveric study
Upper limb neural tension tests (ULNTT's) are used routinely during neck and upper limb examinations to differentiate nerve pathologies from other musculoskeletal pathologies. The current study aimed to identify the effect of the median nerve ULNTT on displacement of the cervical nerve roots C5-8 in cadavers. The authors found that the test resulted in significant inferolateral displacement of the nerve roots.
The upper limb neural tension test 1 (ULNTT1) for the median nerve was performed on 11 cadavers, 6 male, 5 female, with a mean age of 80. The test was performed with the following passive movements: shoulder depression, abduction to 110 degrees, maximal shoulder external rotation, maximal elbow, wrist and finger extension. There was no lateral flexion of the neck. Radiolucent markers implanted into cervical nerve roots 5-8 were used to identify displacement and strain via fluoroscopic imaging. Displacement was in an inferolateral direction (parallel with the root axis) and ranged from 2.16mm to 4.32mm with the C6 and C7 nerve roots showing the most displacement and C5 the least.
The study failed to mention at what point the nerve roots began to displace as the images were only taken in neutral and again at end range. Future studies may assess what effect stressing the joints independently has on displacement. Nevertheless, the study was the first to demonstrate cervical nerve root displacement during the ULNTT and the results at least provide a mechanical foundation for the use of ULNTT's in patients with suspected nerve root involvement.
> From: Lohman et al., Spine 40 (2015) 793-800. All rights reserved to Wolters Kluwer Health, Inc. Click here for the Pubmed summary.