Overview

The sternoclavicular (SC) joint is where the collarbone (clavicle) meets the breastbone (sternum) at the front of the chest. It is the only bony connection between the shoulder girdle and the trunk, and it moves every time you raise or reach with the arm.

Injuries to this joint are uncommon — a small fraction of shoulder girdle injuries — but they can happen with a fall onto the shoulder, a direct blow, a bench-press style load, or higher-energy trauma such as a car accident. Most injuries are sprains, meaning the ligaments are stretched without the joint coming out of place.

Typical Pattern

Pain and tenderness at the base of the collarbone, at the front of the chest
Swelling over the joint
Worse with reaching across the body, pushing, lying on the affected side, or deep breathing
Pain with overhead or carrying activities
A feeling of the collarbone "moving" in some cases

Why It Develops

The SC joint is held together by strong ligaments. Sprains occur when a force transmits along the collarbone — from a fall on the shoulder or an outstretched arm, a direct blow in contact sport, or a heavy pressing load in an awkward position. The ligaments stretch but the joint stays in place.

More serious injuries are dislocations, where the collarbone shifts:

Anterior dislocation — the collarbone end pushes forward, creating a visible bump. It is painful but less dangerous.
Posterior dislocation — the collarbone end pushes back behind the breastbone, toward the windpipe and major blood vessels. This is an emergency.

How It Is Diagnosed

A clinician examines the joint and the movement of both collarbones, and asks about the mechanism. Imaging — X-rays or CT — is used when a dislocation is suspected, because the joint is hard to see clearly on a plain X-ray.

Posterior dislocation is considered seriously when there is difficulty breathing or swallowing, voice changes, or numbness or weakness in the arm — those suggest pressure on structures behind the breastbone.

Treatment

Most SC joint sprains settle with conservative care:

Short-term protection: a sling for comfort for the first few days, then gradual movement
Ice and simple pain relief for the first days
Gentle range-of-motion for the shoulder and chest as pain allows
Graded strengthening for the shoulder blade, chest and upper back before returning to pressing or contact sport
Avoiding the aggravating movement — bench press, lying on the side — until the joint settles

Dislocations need medical management: anterior dislocations can often be reduced and rehabilitated, while posterior dislocations require urgent treatment.

When to Get Assessed

Arrange an assessment for any injury to this joint, especially after a fall, blow or pressing injury, to confirm it is a sprain and not a dislocation.

Seek urgent care if there is difficulty breathing or swallowing, voice changes, numbness or weakness in the arm, or significant chest pain after the injury.

Pec major strain or tear — chest pain with pressing can come from nearby structures
Pain in the chest near the armpit
Sternoclavicular joint anatomy
Clavicle anatomy

References

StatPearls. "Sternoclavicular Joint Injury." https://pubmed.ncbi.nlm.nih.gov/29939671/

This information is for education only and is not a medical diagnosis. InjuryAtlas does not replace an assessment by a qualified health professional. If you have severe pain, visible deformity, numbness, loss of function, or symptoms that are getting worse, seek medical care promptly.

Sternoclavicular Joint Sprain