What is Shoulder Impingement Syndrome?

What is shoulder impingement syndrome?

Impingement syndrome is a common condition affecting the shoulder and is most often seen in aging adults and athletes.  This condition is closely related to shoulder bursitis and rotator cuff tendonitis.  These conditions may occur alone or in combination.  Impingement syndrome is primarily caused by overuse of the shoulder, or from an old shoulder injury, acromioclavicular joint arthritis, a calcified coracoacromial ligament, structural abnormalities of the acromion, and weakness of the rotator cuff muscles. 

The rotator cuff muscle tendons pass through a narrow space between the acromion process of the scapula and the head of the humerus.  Anything which causes further narrowing of this space can result in impingement syndrome.  Inflammation and subsequent thickening of the subacromial bursa may also cause impingement.  Structural abnormalities of the acromion can also cause impingement.

CAUSES

• Increased subacromial loading
• Acromial morphology
• Acromioclavicular arthrosis (inferior osteophytes)
• Coracoacromial ligament hypertrophy
• Eccentric muscle overload
• Subacromial bursal thickening and fibrosis
• Trauma (direct or repetitive)
• Overhead activities (athletic or non-athletic)
• Rotator cuff overload
• Muscle imbalance

SYMPTOMS

• Weakness of shoulder muscles
• Sharp pain with abduction at 70-120 degrees
• Pain with external rotation at 20-30 degrees
• Pain with internal rotation greater than 30 degrees
• Painful arc movement during anterior elevation
• Pain at night, especially when sleeping on the affected shoulder
• Difficulty/pain reaching behind the back
• Pain when a downward force is applied to the acromion
• Superior migration of the humerus due to loss of strength or tear in the rotator cuff

TREATMENT

• Reduce pain and inflammation
• Rest
• Cryotherapy
• Ultrasound
• NSAIDs - anti-inflammatory medication
• Guided rehabilitation
• Surgery, cortical steroids, and injections may be performed if necessary

Whatever is required depends on the degree of shoulder impingement presented, and that is why it is important to have a team of doctors that is able to identify the root injury.  At BBC Health in Lewisville, Texas, we know how to identify, treat, or refer in the proper direction for shoulder impingement injuries. 

Author

Dr. Matthew Gilbert