Shoulder Separation
What is a Shoulder Separation?
A shoulder separation, also called an acromioclavicular (AC) joint sprain, occurs when the ligaments connecting the collarbone (clavicle) to the highest point of the shoulder blade (acromion) are sprained or torn. Unlike a shoulder dislocation (which involves the ball-and-socket joint), a separation specifically affects the small AC joint at the top of the shoulder.
Severity of Injury
Grade I – Mild (Sprain)
Injury: The AC ligaments are stretched but not torn.
Symptoms:
Localized pain and tenderness at the top of the shoulder.
Mild swelling but usually no visible deformity.
Pain with cross-body movements or reaching overhead.
Stability: The joint remains stable.
Recovery: Usually resolves within a few weeks with rest and physical therapy.
Grade II – Moderate (Partial Tear)
Injury: Partial tear of the AC ligaments, and sprain or slight injury to the coracoclavicular (CC) ligaments.
Symptoms:
Moderate pain and swelling.
Tenderness directly over the AC joint.
Pain with lifting, pushing, or overhead activity.
Sometimes a small bump can be seen where the clavicle shifts upward.
Stability: The joint is mildly unstable.
Recovery: May take several weeks to a few months; physical therapy is critical for regaining motion and strength.
Grade III – Severe (Complete Tear)
Injury: Complete rupture of both the AC and CC ligaments.
Symptoms:
Significant pain and swelling initially.
Visible “step-off” deformity where the clavicle sits higher than the acromion.
Weakness and difficulty with overhead or lifting tasks.
Stability: The joint is unstable; the clavicle is displaced upward.
Recovery: Some Grade III cases can be treated successfully with rehab, but surgery may be considered for high-level athletes or those with persistent instability or pain.
Common Symptoms
Pain and swelling at the top of the shoulder
Tenderness directly over the AC joint
Pain with reaching across the body, overhead, or lifting objects
A visible bump at the joint (with more severe separations)
Weakness or difficulty in pressing, pushing, or carrying activities
Physical Therapist Diagnosis
A PT will take a history of the mechanism of injury (often a fall or collision), palpate the AC joint for tenderness, and test motion and strength. Pain provocation tests, such as the cross-body adduction test, may reproduce symptoms. Observation may reveal a step-off deformity in higher-grade separations.
Why it Happens
AC joint injuries typically occur from a direct fall onto the shoulder or from a collision in sports such as football, hockey, or wrestling. The impact forces the acromion downward while the clavicle remains in place, straining or tearing the AC ligaments.
Why it Doesn’t Always Heal on Its Own
Mild sprains may improve with rest, but higher-grade separations can leave instability or chronic pain if untreated. Even mild cases often require therapy to restore motion, strength, and function.
Ideal Physical Therapy Treatment
Treatment depends on the severity, but the goals are to reduce pain, restore motion, and strengthen the surrounding muscles. Dry needling may help relieve upper trapezius or deltoid tension secondary to guarding.
Key strategies include:
Manual therapy for shoulder and thoracic mobility
Dry needling for upper trap or deltoid tension
Targeted strengthening of the rotator cuff and scapular stabilizers
Activity modification to protect the joint during recovery
Gradual return-to-sport progression for overhead and contact athletes
Expected Outcomes
Most mild-to-moderate AC joint injuries recover well with rehab, usually within weeks to a few months. Severe separations may require surgical evaluation, but therapy is still essential for restoring mobility and function.