Virtual Reality Versus Traditional Exercise on EMG Activity in Postural Malalignment (EMG)

This study will investigate the immediate effects of virtual reality (VR)-based exercise compared with traditional exercise on trapezius muscle activation in adults with and without postural malalignment. The study will include approximately 40 adults aged 18-35 years. Participants will be classified according to the presence or absence of postural abnormalities and symptoms.

At baseline, demographic and clinical information will be collected, followed by assessment of forward head posture, rounded shoulder posture, trapezius muscle strength, cervical range of motion, Activity level, craniovertebral angle and joint position sense. Forward head posture will be assessed using the craniovertebral angle obtained through digital photogrammetry, while rounded shoulder posture will be evaluated using the acromion-to-table distance. Symptomatic participants will additionally complete the Numeric Pain Rating Scale (NPRS) and Neck Disability Index (NDI).

Surface electromyography (sEMG) will be used to record the activity of the upper, middle, and lower trapezius muscles. EMG activity will be assessed during relaxed and corrected standing postures and continuously during the exercise conditions. EMG data will be normalized to maximum voluntary isometric contraction (MVIC) and expressed as a percentage of MVIC.

Each participant will complete both the VR-based intervention and the traditional TheraBand exercise intervention during a single study session. The VR intervention will be performed using a Virtualis rehabilitation system with an HTC Vive headset and motion controllers and will involve controlled upper-extremity movements designed to promote appropriate scapular and postural control. The traditional exercise condition will include standing active free exercises targeting the upper, middle, and lower trapezius muscles. A rest period will be provided between the two exercise conditions to minimize the potential effects of fatigue.

The primary comparison will examine normalized trapezius muscle activation during the VR-based and active free exercise conditions. Additional assessments will examine posture, trapezius muscle strength, cervical range of motion, and cervical proprioception. The study is intended to provide information regarding the immediate neuromuscular responses to VR-based rehabilitation and its potential application as an interactive approach to postural rehabilitation.