Electromyographic Evaluation of Muscle Dysfunction in Frozen Shoulder

Background: The symptoms of frozen shoulder include discomfort, stiffness, and restricted shoulder joint range of motion. It can lead to Thyroid, Parkinson’s, and cardiovascular diseases hence it is very much important to diagnose frozen shoulder as early as possible. Electromyography (EMG) plays a crucial role in the diagnosis of the frozen shoulder by analysing the signals obtained. In this study, an attempt has been made to identify frozen shoulder condition using EMG signals. Methods: Subjects with ten normal shoulders and ten frozen shoulders without concurrent spine disorders were included in this investigation. Using EMG MyoWare sensors, signals from the bicep brachii muscles were recorded during isometric maneuvers of flexion and extension that were carried out at $30 \%$ of the maximal voluntary contraction at 90° arm elevation while sitting. Using MATLAB software, the signals were analysed, and features namely signal amplitude and mean absolute value (MAV) were looked for electromyography assessments of patients with frozen shoulders. Results: The results show that the amplitude of the EMG signal acquired from subjects with frozen shoulder is higher than that of the amplitude of the signal of the unaffected subjects. The individuals with frozen shoulders frequently have increased MAV in their EMG readings. Conclusion: This preliminary study demonstrates the possibility of EMG analysis to distinguish between participants with normal and frozen shoulders based on the signal amplitude and MAV characteristics.