Impingement Syndrome

Impingement means ‘catching’ or ‘rubbing’. In this case the impingement of the tendons of the rotator cuff against other structures within the shoulder, such as the subacromial space, under the arch of the acromion (shoulder blade). 

Normally, the ample space between the acromion and the rotator cuff allows the tendons to move easily underneath the acromion when raising the arm.

Impingement Syndrome is a clinical sign, and not a diagnosis in itself. There are several different conditions that may cause impingement syndrome. e.g. supraspinatis tendinitis, subacromial bursitis, labral tear.

Each time the arm is raised, there will be some degree of impingement on the tendons and the bursa as the humerus is being forced against the edge of the acromion. It is only with prolonged or intensive activity involving raising the arm, that impingement can damage or irritate the rotator cuff tendons and the bursa, causing a problem.

Impingement may get worse if another condition decreases the space between the acromion and the rotator cuff tendons. Bone spurs (osteophytes) caused by ageing or overuse of the acromioclavular joint (ACJ) can reduce this space, as this joint is directly above the rotator cuff tendons and bursa.

Impingement syndrome is quite a common condition, most often seen in ageing adults. Impingement may occur in combination with subacromial bursitis and rotator cuff tendinitis, both of which are closely related conditions.

Symptoms

Symptoms of impingement will usually include pain and weakness in the shoulder muscles, especially when lifting the arm over the head, out to the side or reaching up behind the back.

Impingement may make sleeping difficult, especially when rolling on to the shoulder. The joint may start to feel stiffer over time. Severe versions of these symptoms can stem from a rotator cuff tear.

Pain may be experienced at the front/side of the shoulder during overhead activities such as swimming and throwing or at the back/front of the shoulder when holding the arm out to the side and turning outwards.

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