In a 24 year old man weight of the upper limb is transmitted to the axial skeleton by:
**Core Concept**
The coracoclavicular ligament is a key anatomical structure that stabilizes the clavicle by transmitting the weight of the upper limb to the axial skeleton, specifically the sternum and manubrium.
**Why the Correct Answer is Right**
The coracoclavicular ligament connects the coracoid process of the scapula to the clavicle and acts as a primary stabilizer of the clavicle. It functions as a **tension-bearing ligament**, transferring the load of the upper limb to the axial skeleton during weight-bearing. This ligament prevents posterior displacement of the clavicle and is essential in maintaining shoulder girdle stability. It is distinct from other ligaments in its role in weight transmission.
**Why Each Wrong Option is Incorrect**
Option A: The coracoacromial ligament forms a roof over the shoulder joint and protects the supraspinatus tendon; it does not transmit weight to the axial skeleton.
Option C: The costoclavicular ligament is a minor stabilizer that runs from the first rib to the clavicle but is not involved in weight transmission. It is more relevant in shoulder joint stability than load transfer.
Option D: The coracohumeral ligament stabilizes the glenohumeral joint and limits superior translation of the humeral head; it has no role in axial weight transmission.
**Clinical Pearl / High-Yield Fact**
The coracoclavicular ligament is the **primary weight-bearing ligament** of the clavicle. Injury to this ligament (e.g., in acromioclavicular joint dislocation) results in clavicle instability and a "sail sign" on physical examination.
✓ Correct Answer: B. Coracoclavicular ligament