Shoulder impingement, also called sub acromial impingement, is a broad term used to describe shoulder pain that occurs from soft tissue structures in the shoulder becoming “impinged” between the humeral head (ball of the shoulder joint) and the acromion (bony protrusion of the scapula that forms the AC joint).  There are 3 main structures that occupy this space these are the supraspinatus tendon which is one of the 4 rotator cuff muscles, the sub acromial bursa and the long head of biceps tendon.

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The actual pathology and diagnosis in shoulder impingement can be very different from one individual to the next but usually falls into one of the following groups:

• Rotator tendinopathy

• Rotator cuff tear (Partial or full thickness)

• Biceps tendinopathy

• Sub acromial bursitis

 

Causes

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Sub acromial impingement can usually be classified into one of 3 main categories, grouped by cause:

1. Acute or traumatic: onset after a specific event or activity (eg lifting something heavy overhead, throwing or a fall onto the arm)

2. Overuse: seen in people who are doing a lot of overhead activity (eg swimmers) or have recently increased the amount of load or demand on the shoulder

3. Degenerative: commonly seen in people aged 50+ and related to the degenerative changes of the shoulder bones (eg bony spurs) and the soft tissues (eg degenerative fraying or tearing of the tendons).

 

Signs & Symptoms

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• Pain when lifting the arm overhead. The pain is generally worse when the arm is out at the side at 90deg, getting better as it moves up or down. This is known as a painful arc and happens because the sub acromial space is smallest at this position.

• Pain when lying on the affected arm

• Pain when internally rotating the arm, usually seen when putting your hand behind your back (eg fastening a bra strap or scratching your back)

• Symptoms get progressively worse over time

• Some pain referring down the upper arm

• Muscle weakness

• Loss of movement

 

Physiotherapy Treatment

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Your Doctor may diagnose you to have shoulder impingement and it is still relatively common for their first recommendation to be rest, medication, then an ultrasound guided steroid injection. However; it is important to understand that the impingement is consequence, rather than the cause of your condition.

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In most cases sub acromial impingement is caused by muscle imbalance or sub-optimal biomechanics in the shoulder. The large range of motion at the shoulder is made possible by the gliding and moving of the shoulder blade (scapula) and the upper arm bone (humerus) known as scapulo-humeral rhythm. This complex pattern involves many different muscle actions that all have to be working properly to allow normal shoulder function. If there is a problem here that is not corrected then it is likely that the issue will return again at some point. This is why the latest research states that a structured rehabilitation program is the best way to manage sub acromial impingement and this should be the first treatment option before other modalities are considered. This approach has high success rates and most often prevents the need for further treatments such as injections or surgery.

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Physiotherapy Treatment

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The goals of physiotherapy treatment are to reduce the pain and inflammation, then restore range of movement and strength before a graded return to activity is commenced. Management may include:

• A thorough assessment to determine all factors contributing to the problem

• Advice and education re activity modification and required rest

• Soft tissue release techniques (Massage)

• Manual mobilisations of the shoulder joint, AC joint and cervical & thoracic vertebrae

• Targeted rehabilitation / exercise program including ROM stretches and strengthening of the scapular stabilisers, rotator cuff muscles, postural muscle and any other identified weaknesses

 

If you think your symptoms may be caused by shoulder impingement, then call today to book your physiotherapy assessment and get started on the road to recovery.