Effect of cervical contralateral lateral flexion on the median nerve and fascia at the wrist – cadaveric study

Abstract

Background: Neurodynamic tests are an essential aspect of the physical examination of the patient when suspicion of neural involvement exists. A manoeuvre that is hypothesised to move nerves differentially relative to other structures (structural differentiation) has been proposed as a necessary part of neurodynamic testing for differential diagnosis. However, although the specificity of structural differentiation for peripheral nerve over muscle has been demonstrated in some body regions, no study has tested specificity of nerve movement relative to fascia. Objectives: The aim of this study was to measure the effect of the cervical contralateral lateral flexion (CCLF) as an structural differentiation manoeuvre for the median nerve compared to fascia (superficial and deep) at the wrist during the upper limb neurodynamic test 1 (ULNT1). Design: A cross-sectional study was performed in 5 fresh frozen cadavers. Methods: Excursion and strain in the fascia (superficial and deep) and the median nerve were measured at the wrist with structural differentiation during the ULNT1. KINOVEA software was used to measure kinematic parameters. Results: CCLF resulted in significant proximal excursion in the median nerve (p < 0.001*) but not in the strain. CCLF neither produced changes in strain nor excursion in the superficial and deep fascia (p > 0.05). Conclusion: This study showed that CCLF produced significant differential excursion in the median nerve at the wrist compared to the local superficial and deep fascia during the ULNT1. The data support CCLF in mechanical differentiation between nerve and fascia in this area in diagnosis of local sources of wrist pain.