Effect of electromyographic biofeedback training on motor function of quadriceps femoris in patients with incomplete spinal cord injury: A randomized controlled trial

Background Electromyographic biofeedback (EMG BF) training is an effective method of promoting motor learning and control in neurorehabilitation, but its effect on quadriceps femoris muscle in individuals with spinal cord injury (SCI) is unknown. Objective The aim of the study was to investigate the therapeutic effect of EMG BF training on motor function of quadriceps femoris in patients with incomplete SCI. Methods Thirty-three incomplete paraplegic patients with quadriceps femoris strength ranging grade 1 to grade 3 less than 6 months post-injury were enrolled. Control group (n = 16) received conventional physical therapy to enhance quadriceps femoris strength, while intervention group (n = 17) was treated with conventional physical therapy and EMG BF training. All received treatment once a day for 30 days. Surface electromyograph (sEMG), muscle strength and thigh circumference size were assessed to evaluate motor function of quadriceps femoris. Activities of daily living (ADL) was evaluated by Modified Barthel Index (MBI). All the measures evaluated three times in total. Results Compared to the control group, intervention group significantly improved on sEMG values and strength of quadriceps femoris (PsEMG 0.05, PADL = 0.423). Conclusions EMG BF training appeared to be a useful tool to enhance motor function of quadriceps femoris in patients with incomplete SCI. sEMG could quantify the changes of single muscle myodynamia precisely before visible or touchable changes occur.