TOPICS: Thoracic outlet, clavicle, first rib, subclavian artery, subclavian vein, brachial plexus, anterior scalene muscle, middle scalene muscle, posterior scalene muscle, first rib, subclavian artery, subclavian vein, thoracic outlet syndrome, claudication, scalene triangle, anomalous cervical rib, brachial plexus nerve block, rotator cuff muscles, glenohumeral (shoulder) joint, supraspinatus, infraspinatus, teres minor, subscapularis, abduction, adduction, internal rotation, external rotation, suprascapular nerve, axillary nerve, subscapular nerve, glenohumeral joint, acromion, deltoid, scapula, humerus, coracoid process, biceps tendon, latissimus dorsi, trapezius, sternocleidomastoid, pectoralis major, spinal accessory nerve (CN XI), thoracodorsal nerve, pectoral nerves, extension, flexion, abduction, adduction, pectoralis major muscle