Arm abduction involves moving the arm away from the body in the coronal plane. This movement is a complex biomechanical process requiring the coordination of multiple joints, muscles, and stabilising structures in the upper extremity. The glenohumeral joint, or shoulder joint, is the primary site for arm abduction, allowing a range of 90 to 120 degrees depending on individual anatomy and muscle flexibility. The scapulothoracic joint plays a significant role by upwardly rotating the scapula durin