PT Tip of the Month Archive

Impingement Syndrome

Within the body, each joint provides an optimal amount of motion and stability to be successful in functional situations. When a joint allows a large range of motion, it always loses stability. This is often the case for the shoulder joint. In order to perform any type of motion - ranging from simply reaching overhead all the way to throwing a baseball - there must be a large range of motion available.

However, in a situation where there is an increase in motion available combined with any type of dysfunction and/or overuse, a very painful injury called shoulder impingement syndrome can occur.


The shoulder joint is made up of the humerus, the scapula and the clavicle. These three bones form 2 joints within the shoulder. The first joint is the acromioclavicular joint (AC joint) between the acromion of the scapula and the end of the clavicle. The other joint is the glenohumeral joint or the main shoulder joint. The supraspinatus muscle and subacromial bursae (or fluid filled sac) lie between these two joints. The space between the two joints, called the subacromial space, is very limited. When the rotator cuff muscles are irritated, they become inflamed and that space becomes even more limited. This can lead to the rotator cuff muscle becoming pinned against the roof of the subacromial space. When the muscle is forced to the roof of the space, motion is limited. Increased swelling within the muscle will also decrease blood flow to the muscle further decreasing it's functional abilities.


There are many causes of shoulder impingement and injury. These can be classified by either overuse or biomechanical flaws. The majority of shoulder impingement cases are created by overuse. This happens very frequently from overhead work or excessive throwing, both which create an abundance of strain on the shoulder. Shoulder impingement can also be caused by biomechanical factors such as bone spurs and anatomical dysfunctions like having a hook-shaped acromion. Both of these biomechanical flaws can predispose a person to shoulder impingement even with small shoulder tasks.


Symptoms of shoulder impingement syndrome include pain when reaching behind the back or reaching overhead, pain at night especially when lying on the shoulder and pain with any throwing activity. Range of motion and strength are also typically lost as result of the impingement. If the injury becomes chronic, it may develop into a rotator cuff tear or biceps muscle tear, which would decrease the functional abilities of the shoulder.

Diagnosis & Treatment

Initial medical treatment will involve a regimen of anti-inflammatory medications. Anti-inflammatory medications can be helpful with decreasing the acute pain symptoms, but will not ultimately fix the underlying condition. Diagnostic testing may be ordered by your physician to rule out arthritis, or more importantly, partial or full thickness rotator cuff tears.

Surgery can be performed to decompress the area by reshaping the acromion, removing any bone spurs or by performing a resection arthroplasty, which involves removing a portion of the clavicle (collar bone).

Physical Therapy

Whether taking a conservative approach or a surgical approach to treat shoulder impingement, Physical Therapy can be indicated. For conservative, non-surgical, treatment Physical Therapy can help decrease pain and swelling and increase range of motion and strength in the affected shoulder. Since most injuries occur as a result of overuse, treatment will focus on patient education to avoid re-injury and steps to protect the shoulder. Ergonomics can be applied to work practices to also help restore shoulder function and avoid re-injury.

If a surgical approach is chosen to improve your shoulder function, Physical Therapy can help with post-surgical symptoms. Since these surgeries tend to decrease a patient's range of motion and strength in the affected shoulder, Physical Therapy can be indicated post-surgically to minimize your pain and restore the shoulder's functional range and strength.

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