Vagus Nerve Stimulation Effect in Frozen Shoulder Treatment

The goal of this clinical trial is to learn if the addition of transcutaneous vagus nerve stimulation (tVNS) to exercise is effective in improving pain, shoulder function, shoulder range of motion, and psychological factors in adults with frozen shoulder. The main questions this study aims to answer are: Does adding tVNS to exercise reduce shoulder pain ? Does adding tVNS to exercise improve shoulder function and shoulder range of motion? Does adding tVNS to exercise improve psychological factors ? Does adding tVNS to exercise improve patient satisfaction? Researchers will compare the effect of active tVNS added to exercise with sham-controlled tVNS added to exercise to determine whether adding tVNS provides additional benefits in the management of frozen shoulder. Participants will: Receive active tVNS plus exercise therapy or sham-controlled tVNS plus exercise therapy. Attend supervised rehabilitation sessions 3 times per week for 6 weeks. Perform a home exercise program as instructed by the study physiotherapist.