Sonography assessment of the median nerve during cervical lateral glide and lateral flexion. Is there a difference in neurodynamics of asymptomatic people?

There is clinical evidence that cervical lateral glide (CLG) improves neurodynamics and alleviates pain in patients who suffer from neurogenic arm pain. Cervical lateral flexion (CLF) is also a treatment method and a means of testing neurodynamics. However, for both techniques nerve movement has not yet been investigated using ultrasound imaging (US). The purpose of this study was to quantify median nerve movement in the arm during CLG and CLF. For this study 27 healthy participants were recruited. Longitudinal movement of the median nerve was measured using US during CLG and CLF with the shoulder in 30° abduction in the middle and distal forearm (Fad). Data could be obtained from 11 participants (6 women and 5 men, average age 25.6 years, ±2.25) at the middle forearm (Fam) and from 9 participants (5 women and 4 men, average age 27.2 years, ±2.75) at the Fad. When applying CLF, the median nerve moved 2.3 mm (SEM ± 0.1 mm) at the Fam. At the same measuring point the median nerve moved 3.3 mm (SEM ± 0.3 mm, p = 0.005) by applying CLG. At the Fad the difference between CLF and CLF amounted to 0.6 mm (CLF: 1.9 mm (SEM ± 0.2 mm, CLG: 2.5 mm (SEM ± 0.2 mm, p ≤ 0.05). The movements during CLG are larger than during CLF. This difference is statistically significant. However, the statistical relevance cannot be extrapolated to a clinical relevance.