Comparison of Two Ultrasound-Guided Percutaneous Neuromodulation Protocols Applied to the Median Nerve on Maximal Handgrip Strength in Healthy Adults: A Randomized Clinical Trial

BACKGROUND: Ultrasound (US)-guided percutaneous neuromodulation (PNM) has shown promising effects in the neuromuscular field, although its effects in healthy individuals remain unclear. OBJECTIVE: This study aimed to compare the immediate effects of two different US-guided PNM protocols applied to the median nerve on maximal handgrip strength and pain intensity during intervention in healthy adults. MATERIALS AND METHODS: A randomized clinical trial was conducted with evaluator and participant blinding, in which 86 healthy adults were assigned to two groups: protocol 1 (10 Hz, 250 μs, 10 seconds of stimulation followed by 10 seconds of rest) and protocol 2 (100 Hz, 350 μs, 5 seconds of stimulation followed by 55 seconds of rest), each receiving one isolated US-guided PNM session of the median nerve at an individualized, nonpainful, and well-tolerated intensity sufficient to elicit a visible muscle contraction. Maximal handgrip strength was assessed before and after the intervention using dynamometry. Pain intensity during intervention was measured using the Numerical Pain Rating Scale. RESULTS: No statistically significant changes were observed in maximal handgrip strength within groups or between groups. Regarding pain perceived by the participants during the PNM intervention, there were no statistically significant differences between the two groups. CONCLUSIONS: A single session of US-guided PNM did not produce immediate significant improvements in maximal handgrip strength in healthy adults. No significant differences were found between the protocols studied, or in pain perception between groups during the application of the technique, which was safe and well-tolerated. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT07098130.