The effect of single-session electrostimulation on grip strength and hand reaction in healthy individuals: a single-group pre–post interventional study

The hand is an important part for daily activities, and its cortical representation makes it highly sensitive to external stimuli. The aim of this study was to investigate the immediate effects of high voltage pulsed galvanic stimulation (HVPGS) on hand function. A single-group pre–post interventional study was designed in 42 healthy volunteers aged between 18 and 65 years. Participants underwent a single session of HVPGS applied to the hand flexors. Grip strength was measured using a Jamar dynamometer and reaction time was measured using the Nelson hand reaction test. Statistical analyses showed a significant bilateral improvement in all primary outcomes after one session of HVPGS (p < 0.05). In particular, isometric grip strength was significantly greater post-intervention than pre-intervention for the right hand [Median (IQR) 24.42 (10.16) vs. 25.44 (9.13) kg, V = 682.50, p = 0.003] and the left hand [22.60 (10.38) vs. 23.38 (11.83) kg, V = 643.00, p = 0.015]. At the same time, sensorimotor reaction times were significantly reduced (i.e., faster performance) for both right hand (Mean ± SD: 174.8 ± 36.2 ms vs. 154.8 ± 37.1 ms, t(41) = -4.17, p < 0.001) and left hand (168.5 ± 37.8 ms vs. 151.6 ± 33.9 ms, t(41) = -3.48, p = 0.001). Correlation and subgroup analyses suggested that these therapeutic gains were stable and independent of age, sex and BMI (p > 0.05), except for a highly selective interaction between hand dominance and right-hand reaction velocity change (p < 0.001). In this single-group pre–post interventional study, a single session of HVPGS was associated with immediate bilateral increases in hand grip strength and reductions in reaction time. These acute changes were consistent across age, sex, and BMI. Exploratory subgroup analyses suggest potential modulation by hand dominance, though this requires verification in controlled trials. These preliminary observations warrant further controlled investigation to evaluate potential underlying mechanisms. ClinicalTrials.gov NCT07745829. Registered retrospectively on July 30, 2026.