Clinical Research Directory

NMES was applied bilaterally to the abdominal and paraspinal muscles using a COMPEX 3.0 device for 20 minutes. A biphasic rectangular waveform with a pulse duration of 400 μs was used. The protocol included a 2-minute warm-up at 6 Hz, a 75-Hz contraction phase, a 3-minute active rest phase at 4 Hz, and a recovery phase at 3 Hz. Stimulation intensity was individually adjusted according to tolerance, up to 120 mA. The contraction-to-rest cycle was 5 seconds of stimulation and 10 seconds of rest, with 1.5-second ramp-up and 0.5-second ramp-down times. In the experimental group, participants voluntarily contracted the stimulated muscles synchronously with NMES-induced contractions, with emphasis on abdominal bracing and trunk stabilization. Standardized verbal instructions and therapist-guided tactile feedback were provided. The control group received the same NMES protocol without voluntary muscle contraction or active motor engagement.

The program was designed to improve trunk stabilization and lumbopelvic motor control and included supine abdominal bracing exercises (heel slide, unilateral leg lift, and bridging) and quadruped exercises (arm lift, leg lift, and contralateral arm-leg lift).