Shoulder impingement is a common diagnosis for shoulder pain, however, it is considered by many physiotherapists as a symptom of shoulder pain rather than a diagnosis in itself.
What causes impingement?
Shoulder impingement occurs when either the rotator cuff tendons or the subacromial bursa (fluid filled sac to cushion tendon to bone within the shoulder) become inflamed and get irritated as the arm is moved into certain positions. In certain positions the subacromial space in the shoulder is reduced and therefore any inflamed tissue within it gets irritated.
The rotator cuff tendons attach the rotator cuff muscles (group of four muscles essential for shoulder movement and stability) to the bony surfaces.
Often impingement will come on gradually over time as a result of repetitive movements with the arm, but it can also be a sudden onset following a direct trauma to the shoulder i.e. over reaching or falling and landing on the shoulder with the arm outstretched.
What are the symptoms?
The main symptom of shoulder impingement is pain in the shoulder itself and often it can also be painful in the upper arm/deltoid area. This pain may be intermittent only with certain movements, particularly movements involving lifting the arm out to side and up above the head, or reaching behind your back. In some instances, pain may constantly be present as an aching pain, with intermittent sharper pain or catching with movement. It is common to have pain at night with shoulder impingement , particularly laying on your affected side, but also on the other side if the affected arm is then stretched across you. You may also notice some weakness of the shoulder.
How is it diagnosed?
Often shoulder impingement is diagnosed by a physiotherapist without the need for any imaging. A good history of how the symptoms started and the way the symptoms behave, along with a physical examination of your shoulder movement indicates the presence of impingement. There are also some special tests that can be performed which add to the diagnosis.
Considering impingement as a symptom and not a diagnosis in itself, the physiotherapist will also assess scapulohumeral rhythm; which is the way in which the scapula (shoulder blade) and the humerus (upper arm bone) move in relation to each other, as this often has an impact on the volume for soft tissues such as the bursa and the rotator cuff tendons within the subacromial space.
Ultrasound imaging can also be helpful in identifying an inflamed bursa, or any other changes within the rotator cuff tendons which may be contributing to pain.
How is is treated?
There are several ways to manage shoulder pain arising from impingement:
- Applying ice for 10-15 minutes regularly to help reduce inflammation
- Resting the shoulder from aggravating tasks such as repetitive reaching above head height, heavy lifting and carrying
- Physiotherapy helps with symptomatic relief with soft tissue therapy, manual therapy to mobilise the shoulder and rehabilitation to include a strengthening programme for the rotator cuff muscles to increase their tolerance to load and improve their strength and support for the shoulder joint
-In some instances where the pain is too irritable to tolerate physiotherapy treatment, it may be necessary to receive a local steroid injection to settle the inflammation before continuing treatment with the physiotherapy
-Surgical treatment for impingement is considered appropriate in a small number of cases where the pain hasn't been resolved with more conservative measures such as physiotherapy and injection therapy