The Effect of Virtual Reality Training on Anticipatory Postural Adjustments in Patients with Chronic Nonspecific Low Back Pain: A Preliminary Study

Abstract

Objectives. This study is aimed at exploring the effects of virtual reality (VR) training on postural control, measured by anticipatory and compensatory postural adjustments (APAs and CPAs, respectively), in patients with chronic nonspecific low back pain (CNLBP) and the potential neuromuscular mechanism of VR training. Methods. Thirty-four patients were recruited and randomly assigned to the VR group ( $n=11$ ), the motor control exercise group (MCE, $n=12$ ) and the control group (CG, $n=11$ ). The VR group received VR training using Kinect Xbox 360 systems and magnetic therapy. Besides magnetic therapy, the participants in the MCE group performed real-time ultrasound-guided abdominal drawing-in maneuver (ADIM) and four-point kneeling exercise. The CG only received magnetic therapy. Surface muscle electromyography (sEMG) was used to record the muscle activities of transverse abdominis (TrA), multifidus (MF), lateral gastrocnemius (LG), and tibialis anterior (TA) during ball-hitting tasks. The muscle activation time and integrals of the electromyography activities (IEMGs) during the APA and CPA stages were calculated and used in the data analysis. The visual analogue scale (VAS) and Oswestry dysfunction index (ODI) scores were also recorded. Results. A significant interaction effect of $\text{time}\times \text{group}$ was observed on the activation time of TrA ( $p=0.018$ ) and MF ( $p=0.037$ ). The post-intervention activation time of the TrA was earlier in the VR group ( $p=0.029$ ). In contrast, the post-intervention activation time of the MF was significantly delayed in the VR group ( $p=0.001$ ). The IEMGs of TrA ( $p=0.002$ ) and TA ( $p=0.007$ ) during CPA1 significantly decreased only in the VR group after the intervention. The VAS scores of three group participants showed significant decreases after intervention ( $p<0.001$ ). Conclusions. Patients with CNLBP showed reciprocal muscle activation patterns of the TrA and MF muscles after VR training. VR training may be a potential intervention for enhancing the APAs of the patients with CNLBP.