Upper limb

Upper arm bone

Humerus

Origin

Articulates proximally with glenoid cavity of scapula (glenohumeral joint) and distally with radius and ulna (elbow joint)

Insertion

Insertion site for rotator cuff tendons (greater/lesser tubercles), deltoid, pectoralis major, latissimus dorsi, and triceps

Function

Long bone of the upper arm providing structural framework and lever for arm elevation, rotation, and elbow movements

Innervation

Axillary, radial, musculocutaneous, median, and ulnar nerves

Movement & chain

Provides full multi-axial range of motion at shoulder and hinge flexion/extension at the elbow

Palpation

Greater tubercle palpable below acromion; medial and lateral epicondyles palpable at the elbow

Clinical

Proximal humerus fractures in elderly; midshaft fractures with radial nerve palsy (wrist drop); supracondylar fractures in pediatric falls

Segmental innervation

C5–T1

In clinical practice

Key reference for shoulder arthroplasty and safe deltoid intramuscular injections

Region in the model

Upper limb