Impingement syndrome is characterized by pain in the shoulder due to irritation or inflammation of the rotator cuff tendons or the subacromial bursa sitting between the rotator cuff and the bony roof of the shoulder (coracoacromial arch).
As a result of injury, overuse, or relative weakness of the rotator cuff or scapular muscles, the humeral head may not stay well centered when the arm is raised. This can result in contact with the overlying coracoacromial arch, causing pain and inflammation. Repetitive contact over time can result in a rotator cuff tear.
What Is Shoulder Impingement?
The rotator cuff is a series of four muscles—supraspinatus, subscapularis, infraspinatus, and teres minor—which run along the shoulder blade (scapula) and around the shoulder socket (glenoid), surrounding and attaching to the ball of the shoulder (humeral head) by their tendons. The rotator cuff muscles work to keep the humeral head centered in the socket as the arm moves.
Injury, overuse, or relative weakness of the rotator cuff or scapular muscles can cause the humeral head to not stay well centered when the arm is raised. This can result in contact with the overlying coracoacromial arch (bony ligamentous roof), subacromial bursa, and the rotator cuff muscles in between. This contact can cause pain and inflammation, resulting in further rotator cuff weakness and poor shoulder muscular control and creating a cycle of pain with repeated use.
Causes and Risk Factors
Causes and risk factors for shoulder impingement can include:
- Dramatic changes in shoulder activity
- Inactivity and rotator cuff or scapular muscle weakness
- Repetitive use, such as swimming, painting, throwing, or weight lifting
- Age-related narrowing of the space between the roof of the shoulder (coracoacromial arch) and the rotator cuff
- Overhead sports, such as baseball, tennis, swimming, or volleyball
- Weightlifting and bodybuilding that focus on only certain muscle groups, creating muscle imbalances
- Repetitive overhead labor or work
- Previous injury to the rotator cuff, including impingement
- Poor physical conditioning, including strength and flexibility
- Inadequate warm-up or pre-season conditioning before practice or play
Symptoms
Frequent signs and symptoms of shoulder impingement include:
- Pain around the shoulder, often along the front and side of the upper arm
- Pain that is worse when reaching away from the body or overhead
- Occasional aching when not using the arm
- Pain that often awakens you at night
- Occasional loss of strength or difficulty raising the arm
- Occasional crepitation (a crackling sound) when moving the arm
- Biceps pain and inflammation in the front of the upper arm
Diagnosis
If a proper course of conservative treatment does not relieve symptoms, an MRI may be ordered to rule out a rotator cuff tear. MRI is limited and sometimes may miss smaller or partial-thickness tears.
If a patient has failed therapy or has a negative MRI but a history suspicious for a tear, arthroscopic surgery may be recommended to potentially discover and address a rotator cuff tear.
Treatment
Initial treatment consists of therapeutic exercises to restore rotator cuff and scapular muscle strength, endurance, and mechanics to allow proper, non-painful motion of the shoulder. Avoiding activities that aggravate symptoms will also help relieve inflammation and pain. Supervision by an experienced physical therapist is strongly recommended.
A steroid injection to the inflamed area around the tendon (within the bursa) is sometimes recommended for patients who are extremely limited by pain.
If a proper course of conservative treatment does not relieve symptoms, arthroscopic surgery may be recommended to potentially discover and address a rotator cuff tear or perform a subacromial decompression to open the space between the rotator cuff and roof of the shoulder (coracoacromial arch) and alleviate impingement contact and pain.
Recovery and Outcomes
The prognosis for shoulder impingement is usually excellent. A full recovery can usually be expected within six to eight weeks by eliminating aggravating activities and performing therapeutic exercises for the rotator cuff and scapular muscles.
Supervision by an experienced physical therapist or athletic trainer is strongly recommended because it is easy to perform the exercises incorrectly and make the condition worse.
Return to full activity is usually possible in six weeks following therapy alone but may take anywhere from three to six months if surgery is performed.
When to See Dr. Chudik
If shoulder pain persists or worsens, particularly with reaching or overhead activity, or symptoms continue despite conservative treatment, contact Dr. Chudik’s office for an evaluation.
Call 630-324-0402, email contactus@chudikmd.com, or request an appointment online.