Although high intensity strength training can enhance the hypertrophic response and generate optimal muscle strength gains, strength training may not be feasible in patients with a spinal cord injury (SCI). This study assessed the effect of neuromuscular electrical stimulation (NMES) high-intensity training in patients with SCI.

Subjects were five adults with chronic SCI at levels T3-T12, with American Spinal Injury Association Impairment Scale (AIS) scores of B, B, D, A and A. Training included high intensity electrical stimulation, delivered by a high-voltage, constant-current electrical stimulator, placed at the rectus femoris, vastus lateralis and vastus medialis with five sets of 10 repetitions for each leg, twice per week for 12 weeks. Assessments, completed at baseline and at 12-week follow-up, included knee extension torque measurements, muscle cross-sectional area of the quadriceps, as assessed by ultrasound, blood biomarkers for lipid profiles and inflammation as well as measures of spasticity and quality of life.

Compared with baseline, the quadriceps extension torque increased by a mean of 35%, with the cross-sectional area of this muscle group increasing by 47%. In addition, the LDL concentration was reduced by 1.8 (P＝0.06), with a significant increase in the HDL/LDL ratio (P＝0.04) and a near significant decrease in cholesterol/HDL ratio (P＝0.08). Quality of life measures did not significantly increase, while scores on the spinal cord injury spasticity evaluation tool improved by five percent (P＝0.04)．

This study of patients with chronic spinal cord injury found that 12 weeks of high intensity neuromuscular electrical stimulation training can increase knee extensor torque and muscle mass, as well as lipid profiles, though with no significant improvement in quality of life.