Shoulder impingement

What is shoulder impingement?

Shoulder impingement is a term that we use that describes the compression and irritation of one or more of the rotator cuff muscles in the shoulder. There are a couple of reasons why this can happen. When assessing this type of condition, we need to determine whether the impingement is due to some of trauma, repetitive injury, a structural/ mechanical problem within the shoulder or a postural problem.

What is the rotator cuff?

The rotator cuff is the group name for 4 muscles which initiate lifting and turning movements in the shoulder. These muscles originate from the shoulder blade and attach via tendons into the upper arm around the ball/ socket joint of the shoulder.

Symptoms of shoulder impingement include:

• Sharp, catching pain which makes it difficult to pick up the arm. If there is significant weakness, one or more of the rotator cuff tendons could have a tear.
• Localised pain to the front/ outer part of the shoulder
• There might be a painful arc of pain especially when lifting the arm out to the side.
• Pain when sleeping on the painful side
• Difficulty when doing activities like taking off your shirt, where your arm needs to lifted up or taken behind the back

Shoulder impingement due to trauma:

One or more rotator cuff muscles could get injured during a fall onto the shoulder. Trauma could also occur in a sport where the arm could be forced out and back e.g. in a rugby tackle attempt. Attempting to lift a weight that is too heavy could also put too much pressure on the rotator cuff and cause damage.

Shoulder impingement due to repetitive movements:

During certain repetitive movements, such as overhead painting or lifting or in sports where repetitive throwing is required e.g. baseball, excessive strain could be put on the rotator cuff.

Shoulder impingement due to a structural/ mechanical problem in the shoulder:

In some cases, a person can have structural changes which can develop within the shoulder e.g. bone spurs (which are like small growths of bone), which can affect the movement of the rotator cuff and cause pain in the shoulder. Calcium deposits can also develop within the rotator cuff tendons themselves which can also affect movement of the rotator cuff and cause a lot of pain.

Shoulder impingement due to a postural problem:

Muscles around the back, neck and shoulder can all have an effect on how the rotator cuff muscles work.

For example, in people who do a lot of computer work, certain neck muscles can become quite tight. This will have an effect on the position of the shoulder blade. As the rotator cuff muscles originate from the shoulder blade, this will affect how the rotator cuff muscles contract. The rotator cuff tendons pass through a space between the top of the shoulder blade and the ball joint, so if this space becomes smaller, they could become impinged as they contract.

In an initial physiotherapy treatment, it will be important to determine what the cause of the rotator cuff problem is. In cases of trauma or a structural problem, it may be helpful to get an ultrasound or x-ray to see if there are bony issues or tears within the muscle we need to diagnose. In cases with significant bony issues or rotator cuff tears, surgery may be required.

In cases due to repetitive or postural related causes, if the correct contributing factors/ muscles are identified, we will need to work on either releasing/ loosening the tight structures and/ or strengthening the weaker muscles.

Once the cause of the rotator cuff impingement is diagnosed, physiotherapy treatment can include includes: soft tissue release, rotator cuff strengthening, postural stabilisation and strapping.