Shoulder Impingement

What is Shoulder Impingement?

Shoulder impingement, also known as rotator cuff impingement, occurs when the subacromial space between the top of the shoulder (the acromion), and the rotator cuff narrows. This narrowing causes the soft tissues in the shoulder — particularly the bursa and rotator cuff tendons — to become compressed and irritated during movement, especially when lifting the arm overhead.

Bone spurs, inflammation, swelling, repetitive stress, poor posture, and age-related deterioration can all contribute to the narrowing of the subacromial space, resulting in shoulder impingement.

Shoulder impingement is typically painful, often causing sharp pain with overhead motion and a dull ache at rest. The pain may radiate down the front of the shoulder, and the joint may be tender to the touch. Many people find that shoulder pain makes it difficult to sleep. The symptoms of shoulder impingement are collectively referred to as shoulder impingement syndrome.

Causes of Shoulder Impingement Syndrome

Shoulder impingement syndrome is caused by structural or mechanical changes in the shoulder joint. These changes may occur suddenly due to injury or develop gradually in response to repetitive stress or age-related degeneration of the joint.

The following types of joint damage can contribute to shoulder impingement:

• Shoulder joint trauma
• Shoulder bursitis, or inflammation of the fluid-filled sacs on the shoulder joint
• Deformation of the acromion, the bony top of the shoulder blade
• Bone spurs
• Degeneration of the rotator cuff due to aging
• Arthritis in the acromioclavicular joint

Anyone can experience joint damage, but certain sports and occupations increase the risk of developing shoulder impingement by placing repeated strain on the shoulder joint.

Athletes who participate in the following sports are at a higher risk for this condition:

• Baseball
• Discus or other sports involving throwing
• Fly fishing
• Football
• Golf
• Gymnastics
• Swimming
• Tennis
• Volleyball
• Weightlifting

Those working in the following occupations are also at an increased risk of shoulder impingement:

• Carpenters
• Construction workers
• Factory workers
• Painters
• Warehouse workers
• Mechanics

In addition to the repetitive stress of sports or certain occupations, poor posture can contribute to shoulder impingement over time. In some cases, shoulder impingement develops without a clear cause. This is known as idiopathic shoulder impingement.

Symptoms of Rotator Cuff Impingement

Shoulder pain is the primary symptom associated with rotator cuff impingement, more commonly referred to as shoulder impingement. You may experience a dull ache from the pinched tendons and bursa, even when the joint is at rest. That ache may radiate down your arm, and the joint may be stiff or tender to the touch. Lifting your arm overhead typically sharpens the pain.

Other rotator cuff impingement symptoms include:

• Weakness when raising arms above your head or away from the affected side of the body
• Tenderness in the shoulder
• A grinding or catching sensation when using or raising your arm
• Pain that worsens at night, making sleep difficult
• Shoulder stiffness
• Loss of strength and range of motion
• Popping sounds when moving the shoulder

Moderate to severe symptoms of shoulder impingement can do more than keep you off the field or prevent you from working. The pain and stiffness can make simple tasks — like showering or brushing your hair — uncomfortable or even impossible.

Treatment Options for Shoulder Impingement

There are several options for shoulder impingement treatment. In many cases, your doctor may recommend starting with conservative shoulder care for eight to 12 weeks to see if your symptoms improve.

Mild cases of shoulder impingement can be successfully treated at home using the standard approach to soft tissue injuries — RICE therapy (Rest, Ice, Compression, Elevation). Rest by taking a break from the activity that exacerbates the condition. Apply ice for 20 minutes at a time every few hours to reduce inflammation. Compression and elevation are less workable with an injured shoulder than rest and ice.

Over-the-counter anti-inflammatory medications can also help relieve pain. If symptoms of shoulder impingement syndrome persist, your doctor may recommend physical therapy to restore mobility and strengthen the rotator cuff muscles.

In moderate cases, conservative treatment may still provide relief, though it may take weeks or months to recover fully.

Conservative treatment for moderate shoulder impingement includes:

• Icing: Regularly icing the affected shoulder can reduce pain.
• Over-the-counter pain medications: Non-steroidal anti-inflammatories (NSAIDs) such as ibuprofen or naproxen can temporarily relieve pain and swelling.
• Physical therapy: A physical therapist may recommend specific stretching and strengthening exercises to improve shoulder mobility and support the joint.
• Steroid injections: Corticosteroid injections delivered directly into the shoulder joint can help relieve pain and improve your range of motion.

If conservative shoulder impingement treatment options fail to work, or if imaging shows that the subacromial space has grown too narrow, the rotator cuff is badly damaged, or there is severe functional loss, shoulder surgery may prove necessary. That may involve an arthroscopic shoulder decompression, also known as a subacromial decompression (SAD). The goal of the procedure is to create more space for the rotator cuff tendons to move freely without irritation. During this minimally invasive procedure, bone spurs, inflamed bursa, or other structures causing impingement are modified or removed to provide the needed space, thereby relieving pressure on the tendons. This is typically an outpatient procedure performed under general anesthesia.

How Arthroscopic Shoulder Impingement Surgery Works

Arthroscopic shoulder decompression is performed through a few small incisions around the shoulder. The surgeon inserts an arthroscope, a thin tube with a tiny camera, to see inside the shoulder via video transmitted onto a monitor. The surgeon carefully reshapes or clears tissue within the subacromial space using tiny instruments inserted through a small cannula or tube. This gives the rotator cuff tendons more room to move, diminishing pain and restoring normal function.

The small incisions mean less risk of bleeding and a faster recovery. Expect to have your arm in a sling for a specific period post-surgery. Physical therapy should begin shortly after surgery. Most patients can resume normal activities within a few weeks, depending on the severity of their shoulder impingement symptoms.