Clavicle and Rotator Cuff Muscles

Which process is responsible for the development of the clavicle?

Membranous ossification

The clavicle is unique because it:

Is the first bone to appear in the embryo

Why is the clavicle one of the most commonly fractured bones?

It transmits force from a fall onto the outstretched hand

Where is the clavicle most commonly fractured?

Between middle and lateral thirds

What muscle lies directly under the clavicle and helps protect deeper structures?

Subclavius

Which major structures pass beneath the clavicle?

Subclavian artery and brachial plexus

After a clavicle fracture, which muscle pulls the medial fragment upward?

Sternocleidomastoid

What typically causes the lateral fragment of a fractured clavicle to move downward?

Gravity and arm weight

Which of the following muscles is NOT part of the rotator cuff?

Teres Major

Which rotator cuff muscle is located on the anterior surface of the scapula?

Subscapularis

What is the primary function of the rotator cuff muscles as a group?

Stabilise the humeral head in the glenoid fossa

Which rotator cuff muscle assists in initiating abduction of the shoulder?

Supraspinatus

The rotator cuff muscles (except subscapularis) insert on the:

Greater tubercle of humerus

What important structure lies in the intertubercular (bicipital) groove?

Long head of biceps tendon

Which rotator cuff muscle is primarily responsible for medial rotation of the shoulder?

Subscapularis

The posterior compartment of the upper arm is innervated by which nerve?

Radial nerve

The musculocutaneous nerve innervates muscles of which compartment?

Anterior arm

What does the epiphyseal line seen on a shoulder X-ray represent?

A site of endochondral ossification