Musculoskeletal Plasticity After Acute Spinal Cord Injury: Effects of Long-Term Neuromuscular Electrical Stimulation Training

This study investigates whether long-term neuromuscular electrical stimulation (NMES) training can preserve muscle and bone health in individuals with spinal cord injury (SCI). The research focuses on the plantar flexor muscles and distal tibia bone mineral density. Subjects began unilateral plantar flexion electrical stimulation training within 6 weeks after SCI, with one leg serving as the trained limb and the other as the untrained control. The training lasted for two years, with a mean compliance of 83%. The results showed that the trained limbs exhibited significantly better muscle properties (torque, fatigue resistance, contractile speed) and higher bone mineral density compared to the untrained limbs, suggesting that long-term NMES training can mitigate musculoskeletal deterioration after SCI.

• 1
  Long-term NMES training resulted in significant improvements in plantar flexor muscle properties, including increased peak torque (+24%), torque-time integral (+27%), fatigue index (+50%), and torque rise time (+45%).
• 2
  Peripheral quantitative computed tomography revealed a 31% higher distal tibia trabecular bone mineral density (BMD) in the trained limbs compared to the untrained limbs.
• 3
  The estimated compressive loads delivered to the tibia during training were approximately 1–1.5 times body weight, suggesting that the training protocol provided sufficient mechanical stress for bone adaptation.