Restorative neurostimulation of the lumbar multifidus muscles improves mobility, strength, pain and disability in patients with mechanical chronic low back pain

Abstract Purpose To assess the impact of restorative neurostimulation on patient reported outcomes in patients with mechanical chronic low back pain (LBP) presenting to real-world spine surgical practices, and the impact on measures of physical function and lifestyle tracking. Methods This was prospective observation study of a single group of patients treated for mechanical chronic LBP with electrical stimulation of the lumbar multifidus muscles. Patients were included it they were deemed suitable for implantation of the device by two spine surgeons. Prior to implantation, measures were made of patient reported outcomes (pain, disability, quality-of-life, fear avoidance, pain self-efficacy, and physical/mental/social health), quantitative measures of physical function (trunk strength, balance, lumbar range-of-motion, 30-second sit-to-stand and timed up-and-go), and lifestyle tracking measures of physical activity and sleep. Measures were repeated at 8 weeks, 6 months, and 1 year post-implantation. Results 28 males and 22 females with a mean age, body mass index, and pain duration of 56 ± 12 years, 28.2 ± 4.2 kg/m 2 , and 19 ± 13 years, respectively, participated. Prior to 1 year, two participants withdrew and underwent explantation. By 1 year, significant improvements were noted across all patient reported outcomes except cognition, anxiety, depression, and fatigue. Trunk extension and flexion strength significantly improved, as did the 30-second sit-to-stand and timed up-and-go. No changes in physical activity or sleep were observed, except an increase in minutes spent in light sleep. Conclusion This study provides real-world evidence for the longitudinal benefits of restorative neurostimulation for patients with mechanical chronic LBP and is the first to demonstrate objective improvements in trunk strength and physical function.