Effects of different neuromuscular electrical stimulation techniques applied to the multifidus muscle on the kinematics of the spine, pelvis, and hip during sit-to-stand in individuals with chronic nonspecific Low back pain

Purpose To investigate the effects of two neuromuscular electrical stimulation (NMES) techniques applied to the lumbar multifidus on spine, pelvis, and hip kinematics during sit-to-stand (STS) in individuals with chronic nonspecific low back pain (CNLBP).Methods Twenty-two individuals with CNLBP were randomized into conventional NMES (CNMES; n = 11) or functional NMES (FNMES; n = 11) groups. A control group of ten healthy individuals was included for comparison. The CNMES group received stimulation in the prone position without voluntary contraction, whereas the FNMES group received stimulation during STS. Interventions were delivered three times weekly for eight weeks. Kinematic parameters were assessed using optoelectronic motion capture, and pain and disability using the Visual Analog Scale and Oswestry Disability Index.Results At baseline, CNLBP groups showed reduced range of motion and angular velocity during the flexion phase of STS. After the intervention, the FNMES group demonstrated significant improvements in spine, pelvis, and hip kinematics (p < 0.05), while only spine angular velocity improved in the CNMES group. Both NMES groups demonstrated significant reductions in pain and disability levels (p < 0.05).Conclusion FNMES was more effective than CNMES in improving movement patterns during the flexion phase of STS, demonstrating its potential as a phase-specific rehabilitation approach for individuals with CNLBP.