A Novel Virtual Reality Intervention Combining Movement Exercises and Body Illusions for the Treatment of Chronic Back Pain: Prospective Feasibility Study.

Background: Virtual reality (VR) has proven effective in delivering nonpharmacological interventions to reduce acute and chronic pain. For the treatment of nonspecific chronic low back pain (CLBP), it offers benefits over traditional treatment options, such as the possibility of gamified movement exercises with real-time performance feedback and virtual embodiment. We implemented a novel immersive VR intervention (a serious game) that combined these elements. Objective: This study evaluated the feasibility, tolerability, and initial clinical efficacy of the gamified VR intervention. Methods: Patients with CLBP (n=20; mean age 47, SD 14 years; symptom duration >3 months to ≤5 years; convenience sample) took part in a prospective, single-arm, and preregistered trial over 9 weeks. The VR therapy phase lasted 3 weeks, and there were 2 VR sessions per week conducted at the University Hospital Wuerzburg (Germany). Before the therapy phase, there was a 2-week baseline phase, and the posttherapy phase lasted 4 weeks. During the sessions, patients wore a head-mounted display. In VR, they embodied a virtual avatar and performed gamified movement exercises. Participants were immersed in a virtual toy factory, and they had the task of teaching 5 different toys how to move. They received real-time feedback on performance through a hologram overlaying their avatar. Based on performance, movements to be performed became gradually more difficult (graded exposure). Primary outcome measures were adherence and side effects for assessing feasibility and tolerability (Simulator Sickness Questionnaire), and pain intensity ratings (numerical rating scale 0-10) were used for assessing initial clinical efficacy. Secondary outcomes included back- and task-specific functioning and questionnaires to further test initial clinical efficacy and assess fear-avoidance beliefs. Results: Adherence was high (18/20, 90%). Participants indicated lower pain in the posttherapy phase compared with baseline levels (mean difference 0.73, CI 0.27-1.19; t16=3.38; P=.004; d=0.82). There were only few and minor side effects. Task- and back-specific functioning improved (ie, performing daily life activities; Back Performance Scale: F2,34=4.53; P=.02; η2g=0.04; Roland-Morris Disability Questionnaire: F2,26=4.73; P=.02; η2g=0.08), and movement restrictions decreased (F2,32=10.82; P<.001; η2g=0.06). There were no changes in the psychological outcome measures (eg, fear avoidance beliefs). Across all VR sessions, study participants reported high levels of fun (mean 8.07, SD 1.99). Conclusions: We implemented a gamified immersive VR intervention for the treatment of CLBP. The combination of gamified movement exercises and virtual body illusions is unique, and for the first time, it included real-time feedback via a hologram overlaying the virtual avatar of the user. The study demonstrated the feasibility and safety of the intervention. Initial tests of the clinical efficacy revealed positive effects on pain, physical functioning, and daily activities. However, these did not reach the thresholds of clinical importance. A randomized controlled trial is needed to test the specificity of the effects.