Effectiveness of Smartphone Vibrotactile Biofeedback on Postural Correction and Neck Pain Reduction in Desk Workers with Chronic Neck Pain: A Randomized Controlled Trial

Abstract Background and Purpose: Chronic neck pain (CNP) is among the most prevalent occupational health complaints in desk-based workers globally, with reported lifetime prevalence exceeding 70% in office populations. Despite substantial evidence supporting exercise-based physiotherapy for CNP, patient adherence to unsupervised postural correction programs remains persistently poor. Vibrotactile biofeedback — the delivery of real-time haptic alerts via skin vibration when a threshold postural deviation is exceeded — has shown promise in occupational and surgical settings, yet no published randomized controlled trial has evaluated smartphone vibration motor based biofeedback specifically for postural correction and neck pain reduction in chronic neck pain desk workers. This study addresses that clinical and technological gap. Methods: A parallel-group, assessor-blinded randomized controlled trial will be conducted with 96 desk workers (aged 22–55 years) with a physiotherapy-confirmed diagnosis of chronic nonspecific neck pain of at least 12 weeks duration. Participants will be randomly allocated 1:1 to either a 6-week smartphone vibrotactile biofeedback intervention (PostureAlert app, n=48) or a standard postural education and exercise program (control, n=48). The PostureAlert app uses the smartphone’s built in accelerometer to continuously monitor head and neck tilt angle during desk work; when cervical flexion exceeds a pre-set threshold of 30°, the phone vibrates for 2 seconds as a corrective haptic cue. Primary outcomes include neck pain intensity (Numeric Pain Rating Scale, NPRS) and sagittal cervical posture angle (craniovertebral angle, CVA) measured at baseline, 3 weeks, and 6 weeks. Secondary outcomes include neck disability (NDI), forward head posture grade, daily productive posture time, and participant satisfaction. Expected Significance: This trial is the first to isolate the vibration motor of a common smartphone as the sole biofeedback delivery mechanism for chronic neck pain rehabilitation in office workers. Given that smartphone ownership in India now exceeds 700 million users and desk-work populations continue to grow, a validated, zero-cost, hardware-free intervention of this nature would carry major public health relevance and immediate scalability.