Upper limb

Shoulder blade

Scapula

Origin

Flat triangular bone on posterolateral thorax; articulates with clavicle (AC joint) and humerus (glenohumeral joint)

Insertion

Attachment site for 17 muscles including rotator cuff group, trapezius, serratus anterior, and rhomboids

Function

Forms mobile base for upper limb movement; glides on thoracic wall via scapulothoracic articulation

Innervation

Suprascapular, accessory, dorsal scapular, and subscapular nerves

Movement & chain

Elevation, depression, protraction, retraction, and upward/downward rotation (scapulohumeral rhythm)

Palpation

Spine of scapula, acromion, medial border, inferior angle, and coracoid process are prominent landmarks

Clinical

Winged scapula (scapula alata due to long thoracic nerve injury); subacromial impingement; scapular dyskinesis

Segmental innervation

C3–C8

In clinical practice

Essential landmark for shoulder rehabilitation, trigger point therapy, and biomechanical assessment

Region in the model

Upper limb