A lateral shoulder X-ray (scapular Y or lateral view) is a radiographic projection taken from the side to visualize the shoulder’s bony anatomy—scapula, humeral head, acromion and coracoid processes. It helps assess dislocations, fractures, impingement and alignment. The patient is positioned so the scapula appears in profile; it’s commonly used alongside AP and axillary views for full evaluation.

The three standard shoulder X‑ray views are: 1) Anteroposterior (AP) view—shows the glenohumeral joint and proximal humerus; 2) Axillary view—visualizes joint congruity and humeral head position relative to the glenoid; 3) Scapular Y (lateral) view—assesses dislocation, acromion, coracoid and scapular alignment. Together they detect fractures, dislocations, and guide clinical management.

Position patient upright facing the cassette with the affected shoulder against it. Rotate the torso 45–60° toward the cassette so the scapula appears lateral and forms a “Y” (acromion, coracoid, scapular body). Keep the arm neutral or across the chest. Center the x‑ray beam perpendicular to the scapulohumeral joint, include the whole scapula, suspend respiration, collimate, and use a grid for adults.

A left shoulder X-ray can show fractures, bone dislocations and joint alignment, degenerative arthritis (joint space narrowing, osteophytes), bone infections or tumors, calcifications from tendinitis, and foreign bodies. It detects bone density changes and advanced avascular necrosis, and helps assess surgical hardware. It does not show soft-tissue injuries (rotator cuff tears) well; further imaging (MRI/ultrasound) may be needed.

A lateral view is an X‑ray taken from the side of the body, perpendicular to the frontal (AP/PA) projection. It shows depth and spatial relationships of structures, helping localize lesions, detect fractures, assess spinal alignment, and reveal pleural effusions or soft‑tissue abnormalities. Lateral images are commonly used with frontal views (chest, spine, extremities) to provide a complete evaluation.

The posterior shoulder is the back part of the shoulder girdle—over the scapula and posterior deltoid—housing rotator cuff muscles (infraspinatus, teres minor) and joints involved in external rotation. The lateral shoulder is the outermost side over the acromion and lateral deltoid, the common site of subacromial bursa and tendon pain; it’s key for abduction and arm elevation.