[A comparative study on the surface electromyography of lumbosacral multifidus muscle in patients with lumbar disc...

To compare the degeneration of lumbosacral multifidus muscle in patients with lumbar disc herniation.

Thirty-five healthy volunteers and 35 patients with unilateral L_4,5 lumbar disc herniation from December 2015 to September 2017 were recruited. There were 20 males and 15 females in each group, aged from 25 to 55 years old. In healthy volunteers group, the mean age was (35.66±8.73) years old and the BMI was (21.85±1.94) kg /m². In patients with lumbar disc herniation, the mean age was (36.09±7.70) years old, the BMI was (21.50±1.78) kg /m², the VAS score was 4.40±0.88, the course of disease was (11.20±7.14) months. Surface electromyography analysis was performed on the multifidus muscle of the two groups. The average myoelectric amplitude of the multifidus muscle in the two groups were compared.

The average myoelectric amplitude of the multifidus muscle of healthy volunteers was (48.84±7.77) µV on the left and (49.13±7.86) µV on the right. There was no significant difference between the two sides (P>0.05). The average myoelectric amplitude of multifidus muscle in patients with lumbar disc herniation was(48.82±8.14) µV on the healthy side and (42.81±7.00) µV on the affected side, and the difference was statistically significant between two sides(P<0.05). There was no significant difference in the average myoelectric amplitude of multifidus muscle between the healthy side of lumbar disc herniation and on the left of healthy volunteers, or between the healthy side of lumbar disc herniation and on the right of healthy volunteers (P>0.05). There was significant difference in the average myoelectric amplitude of multifidus muscle between the affected side of lumbar disc herniation and on the left of healthy volunteers, and also between the affected side of lumbar disc herniation and on the right of healthy volunteers(P<0.05).

Patients with chronic lumbar disc herniation have an imbalance in myoelectric activity, and the muscle strength of the multifidus muscle on the affected side is significantly reduced.