SHOULDER IMPINGEMENT SYNDROME OVERVIEW

Impingement syndrome occurs when tendons of the rotator cuff and the subacromial bursa (a fluid-filled sac that separates the bones of the shoulder joint) are compressed between the bones of the shoulder.

Doing work with the arms outstretched overhead can cause shoulder soreness but does not necessarily cause impingement; shoulder impingement syndrome is only diagnosed when symptoms persist and interfere with normal daily activity. Chronic impingement may lead to bursitis, rotator cuff tendinopathy, and, if left untreated, thinning or tearing of the rotator cuff tendons. (See "Patient information: Rotator cuff tendinitis and tear (Beyond the Basics)" and "Patient information: Bursitis (Beyond the Basics)".)

The goals of treatment for this condition include:

• Reducing the degree of impingement by increasing the size of the subacromial space
• Preventing injury to the rotator cuff tendons

Treatment typically includes stretching and strengthening exercises and limiting overhead reaching and positioning. The chances of recovering from shoulder impingement are excellent when these treatments are used.

LIMIT ACTIVITY

Eliminate lifting and restrict over-the-shoulder positions and reaching until your symptoms have resolved. Avoid overhead reaching, reaching across the chest, lifting, leaning on the elbows, and sleeping directly on the shoulder.

• Lift objects close to the body
• Only lift light weights below shoulder level
• Do sidestroke or breaststroke when swimming
• Throw balls underhand or sidearm
• Do not serve overhand in tennis or volleyball
• Maintain good posture with writing, assembly work, etc.

Do not use an arm sling to limit activity; this may lead to the development of a frozen shoulder (stiff shoulder joint) (see "Patient information: Frozen shoulder (Beyond the Basics)").

SHOULDER IMPINGEMENT SYNDROME PAIN RELIEF

Ice can be used to reduce the inflammation that often occurs in shoulder impingement. Ice can be applied for 15 minutes every four to six hours as needed.

If needed, a non-prescription pain medication such as acetaminophen (Tylenol®), ibuprofen (eg, Advil®, Motrin®) or naproxen (eg, Aleve®) can be taken. (See "Patient information: Nonsteroidal antiinflammatory drugs (NSAIDs) (Beyond the Basics)".) No more than 4000 mg of acetaminophen is recommended per day. Anyone with liver disease or who drinks alcohol regularly should speak with his or her healthcare provider before taking acetaminophen.

SHOULDER IMPINGEMENT SYNDROME STRETCHING EXERCISES

Stretching (range-of-motion) exercises are recommended early in the recovery period. These exercises are intended to help maintain joint mobility and flexibility of the muscles and tendons in the shoulder. You should not feel more than mild pain with any range-of-motion/flexibility exercise. If you feel sharp or tearing pain while stretching, stop exercising immediately and consult a healthcare provider.

Weighted pendulum stretch — The weighted pendulum stretching exercise performs two functions:

• Gently stretches the space in which the tendons pass to relieve pressure on the tendons
• Prevents the development of a frozen (stiff) shoulder

This exercise can be started almost immediately after a shoulder injury, or after receiving a steroid injection into the shoulder joint. This exercise should be performed after heating for five minutes once or twice per day. The exercise is performed as follows (figure 1):

• Relax your shoulder muscles
• While standing or sitting, keep your arm vertical and close to your body (bending over too far may pinch the rotator cuff tendons)
• Allow your arm to swing forward to back, then side to side, then in small circles in each direction (no greater than 1 foot in any direction). Only minimal pain should be felt.
• Stretch the arm only (without added weight) for three to seven days. Progress this exercise by adding 1 to 2 pounds (0.5 to 1 kg) each week and gradually increasing the diameter of the movements (not to exceed 18 to 24 inches or 45 to 60 cm )
• After a few weeks this exercise should be supplemented or replaced by other exercises to target specific areas of tightness/restriction. The pendulum stretch may be recommended as a warm up for more localized flexibility exercises and/or strengthening exercises.

When performed correctly the pendulum exercise should not result in more than mild discomfort. If more pain is felt, consult a healthcare provider for instructions.

Muscle-strengthening exercises — Muscle-strengthening exercises are necessary to improve shoulder muscle strength and help to prevent further injury. These exercises can often be started approximately one to two weeks after beginning the pendulum stretch exercises, once any acute inflammation has resolved, or after having a steroid injection into the shoulder joint. Consult with your provider or physical therapist to determine when to begin strengthening exercises.

As pain improves, the level of difficulty of these exercises should be increased. Increased resistance is necessary to improve muscle strength to a degree that reduces the risk of re-injury. Mild soreness is expected with these exercises, although pain should not continue for more than 24 hours. Sharp or severe pain during or after exercising may indicate a flare of the underlying problem; stop these exercises for a few days if this occurs.

Preparing for strengthening exercises — The joint should always be heated for five minutes and stretched with range-of-motion exercises before beginning strengthening exercises (see 'Shoulder impingement syndrome stretching exercises' above).

Rest after stretching for two or three minutes, then perform 15 to 20 repetitions of each exercise slowly, holding for one to two seconds during each exercise. Flexible rubber tubing, a bungee cord, or a large rubber band can be used for each exercise (figure 2).

Scapular squeezes — Lie on your back with your knees bent and feet flat (picture 1). Your arms should be straight out, 6 to 12 inches (15 to 30 cm) away from the side of your body, with palms facing upward. Keeping your low back flat against the ground, squeeze your shoulder blades downward and towards each other, towards the spine. Make a conscious effort not to shrug your shoulders and keep the neck relaxed. You should feel the lower muscles between your shoulder blades contracting. Hold for five seconds and repeat 20 times. Do this exercise two to three times per day.

The difficulty can be increased by performing the exercise while sitting and then by holding a piece of tubing in each handing and pulling the hands apart while squeezing the shoulder blades together, as described above.

Outward rotation exercise — Hold your elbows at 90 degrees, close to your sides; holding a towel between your torso and the inside of your elbow will cue you to keep your elbow by your side. Hold one end of a rubber band in each hand and rotate the affected forearm outward 2 or 3 inches, holding for five seconds (picture 2).

Perform the exercise through all available pain-free ranges of motion. Keep the shoulder blades squeezed down and back while performing this exercise.

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient information: Shoulder impingement (The Basics)
Patient information: Rotator cuff injury (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient information: Rotator cuff tendinitis and tear (Beyond the Basics)
Patient information: Bursitis (Beyond the Basics)
Patient information: Frozen shoulder (Beyond the Basics)
Patient information: Nonsteroidal antiinflammatory drugs (NSAIDs) (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Evaluation of the patient with shoulder complaints
Radiologic evaluation of the painful shoulder
Rotator cuff tendinopathy
Shoulder impingement syndrome

The following organizations also provide reliable health information.

• National Library of Medicine

      (www.nlm.nih.gov/medlineplus/healthtopics.html)

• American Physical Therapy Association

      (www.apta.org)

• American Academy of Orthopedic Surgeons

      (www.aaos.org)