Effect of Neural Mobilization on Pain, Conduction Velocity and Muscle Activity in Diabetic Peripheral Neuropathy — Multi-arm Randomized Controlled Study

Objective: The study aimed to determine the effects of the addition of neural mobilization (NM) to resistance exercises for 8 weeks on neuropathy symptoms, neurophysiology, and muscular properties in patients with diabetic peripheral neuropathy (DPN). Material and methods: Thirty-three subjects were recruited and distributed equally to three groups. The first group was given neural mobilization and resistance exercise (NME), second group was given resistance exercise only (EX) for 3 days/week, and in the third group, no exercise was given (CG). Pain; fasting glucose and glycated hemoglobin (HbA1c) levels; nerve conduction velocity (NCV) of the tibial, peroneal, and sural nerves; muscle activity [average maximum voluntary isometric contraction (averageMVIC); %MVIC; co-contraction index, CCI] were measured at baseline and after 8 weeks. Baseline comparison analysis was performed with one-way ANOVA, and between-groups comparison was performed with 2 × 3 repeated-measures ANOVA. Results: All the groups were similar at baseline and no significant difference was found, except for NPRS and conduction velocity of peroneal nerve. The NCVs of both the tibial and sural nerves showed significant time effects (p < 0.001, p < 0.05), group effects (p < 0.001, p < 0.05), and time × group interaction effects (p < 0.001, p < 0.05). The average MVIC of tibialis anterior showed a statistically significant time effect (p < 0.01) and group × time interaction effect (p < 0.05), but no significant group effect (p > 0.05). The CCI significantly improved with time (p < 0.05), and when compared between the groups (p < 0.01). Conclusions: Neural mobilization may be used as an adjunct to improve the conduction velocity in patients with moderate severity of DPN. The study is registered prospectively in The Clinical Trials Registry — India with reference no. CTRI/2022/06/043564.