Side-to-side range of movement variability in variants of the median and radial neurodynamic test sequences in asymptomatic people

Abstract

Side-to-side discrepancy in range of motion (ROM) during upper limb neurodynamic testing is used in part to identify abnormal peripheral nerve mechanosensitivity and is one of three factors to consider in determining a positive test. Large side-to-side variability is reported for some variants of the upper limb neurodynamic test sequences, however discrepancies for other test variants are unknown. Hence the purpose of this study was to evaluate side-to-side discrepancy in elbow flexion ROM during two variants of upper limb neurodynamic test sequence for the median and radial nerves. 51 asymptomatic subjects (26 females, mean age 29.69 years) were evaluated. A uniaxial electrogoniometer was used to measure elbow flexion ROM at onset of resistance (R1) and onset of discomfort (P1) during the median and radial neurodynamic tests on each side. Reliability was determined by testing 20 subjects twice and was found to be good (ICC greater than 0.88 and SEM less than 4.02°). There was no significant difference in mean ROM between sides. Lower-bound scores indicate that intra-individual, inter-limb differences of more than 15° for the median nerve and 11° for the radial nerve exceeds the range of normal ROM asymmetry on neurodynamic testing at R1 and P1. Correlation of ROM between limbs was significant with R2 values of 0.62 and 0.85 for the median and radial nerves respectively. These finding provide clinicians with information regarding normal side-to-side variability in ROM during two commonly used variants of neurodynamic tests.