Pain and injury in the shoulder can have a variety of causes. One of the most common issues we see is shoulder impingement. So what is shoulder impingement? Shoulder impingement refers to a condition where poor co-ordination causes certain structures within the shoulder to get squashed or compressed when moving. Everyone is different and there are several reasons why the shoulder may be moving poorly, including muscle tightness, nerve irritation or muscle weakness. Working out the main contributing factors for each person is key to establishing how to fix shoulder impingement.
What Is Shoulder Impingement?
Understanding shoulder anatomy helps explain what shoulder impingement is. What we think of as the shoulder is referred to as the glenohumeral joint. It is a ‘ball and socket’ joint made up of the humerus (upper arm bone and ‘ball’ component) and the glenoid fossa (the ‘socket’ component that is on the edge of the shoulder blade). A roof is formed at the top of this joint by the acromion (part of the shoulder blade) and the collar bone. The space between this roof and the humerus is called the subacromial space. Tendons for the muscles that create movement and stability in the shoulder as well as bursa (small fluid filled sacs) which help reduce friction sit in the subacromial space. During normal shoulder movement, the humerus glides downwards within the socket as the arm is raised to allow smooth and pain-free movement. When shoulder impingement is present, the humerus does not glide properly and ends up pushing up into the structures at the top of the joint. These include the bursa, acromion and tendons of the rotator cuff muscles. As the humerus ‘impinges’ on these structures the result is poor movement patterns, pain and weakness in the shoulder. Shoulder impingement is quite common, with some data suggesting it accounts for 50% of all shoulder pain.
What Is an Impingement in the Shoulder Caused By?
We understand that shoulder impingement is due to the humerus not gliding properly, but what causes this to occur in the first place? There are a number of causes of shoulder impingement. Muscle tightness in shoulder muscles – particularly the ones that run through the subacromial space – can contribute to shoulder impingement. Tightness in these muscles may occur due to poor posture or overuse, especially in overhead positions (such as swimming, throwing or repetitive overhead lifting). An imbalance in the strength of muscles around the shoulder may also contribute to poor movement patterns which in turn can cause shoulder impingement. Due to the hard bony surrounds of the subacromial space, swelling causes a reduction in space for the tendons and bursa and therefore cause shoulder impingement. Swelling might be due to another injury such as a labrum tear or bursitis caused from a traumatic event (such as a fall onto the shoulder). In a small percentage of cases, some people are predisposed to shoulder impingement due to slight variations in the shape of their bones, in particular the shape and angle of the acromion. Sometimes, repetitive activities can also contribute to the growth of bone spurs which also fill the space and contribute to impingement.
Shoulder Impingement Symptoms
Shoulder impingement can have a variety of symptoms. We can use symptoms to help determine what is shoulder impingement and what is a different shoulder condition. In most cases, knowing the symptoms alongside some physical tests with a physio is sufficient to establish if the problem is shoulder impingement. However sometimes imaging (such as an ultrasound or MRI) may also be used to help make a diagnosis. Key symptoms that may be experienced with shoulder impingement include:
- Pain – most people will experience pain either at the front of the shoulder or on the outer part of the upper arm. Pain can vary from a dull ache to a sharp, pinching type feeling. You may also get pain into the neck or upper back as well. Pain will usually be aggravated with particular movements of the shoulder – in particular overhead movement such as swimming, throwing or even washing/brushing your hair or reaching into a high cupboard. Reaching behind you, either into your back pocket or to do up your bra may also cause pain. Many people also find lying on the affected arm can also provoke pain and may find sleep is quite interrupted as a result.
- Restricted range of motion – often the aggravating movement mentioned (reaching overhead or behind you) will start to feel limited in range.
- Weakness – many people will find they feel weaker in the affected arm when they have shoulder impingement
Is Shoulder Impingement Permanent?
Given how painful and disruptive shoulder impingement can be, it is understandable to question whether it can be fixed. Knowing that often the cause is due to changeable factors such as overuse, muscle tightness or weakness helps us understand that it usually can be fixed. Some people may have more difficulty solving their impingement (for example if they have a predisposing acromion shape), but with a combination of physio, medication and activity modification most people should make a full recovery.
How to Fix Shoulder Impingement:
Treatment for shoulder impingement is usually centred around physiotherapy. Other modalities may be incorporated alongside physio treatment. Shoulder impingement treatment with a physio may include:
- Nerve treatment – its common for the nerves of the arm to also get irritated and treatment to the spine may be needed to help restore normal movement of the arm nerve
- Muscle releases or massage – as tight muscles can be the cause of shoulder impingement, hands on treatment to release the muscle tightness usually plays an important role in restoring normal shoulder movement and resolving impingement. Treatment for muscles can include trigger pointing, massage or even dry needling.
- Spinal joint mobilisation – full shoulder movement is also dependent on neck and thoracic spine movement. Stiffness in the neck/thoracic spine may be present with shoulder impingement so your physio may include treatment to the neck or upper back to ensure restoration of full movement and good mechanics
- Activity modification – in the early stages of treatment, your physio will likely advise you to avoid aggravating activities, such as swimming, throwing or overhead strength exercises. These adjustments should only be temporary to allow the inflammation to settle down and once your shoulder is moving better, your physio can help you gradually add these activities back in
- Postural advice – poor shoulder posture can contribute to the development of shoulder impingement or may occur as a result of compensation when the shoulder is painful. Either way, to reduce the chance of future shoulder problems your physio may give you advice about shoulder posture
- Muscle retraining – retraining the muscles in the shoulder is a key step in rehabilitating shoulder impingement. Your physio should give you specific exercises that focus on ensuring the muscles are co-ordinating and working together properly. Once good movement patterns have been established the focus can then shift to strengthening to help make your shoulder more resilient to future injury
Talk to a Physio Today About Shoulder Impingement Syndrome
Shoulder impingement is a very common cause of shoulder pain and dysfunction. While it can be very limiting and disruptive to daily life it is responsive to physiotherapy treatment so you don’t need to continue suffering. If you have shoulder pain or think you might have shoulder impingement, contact the team at Barefoot Physiotherapy today to discuss it further or book in so they can complete a thorough assessment and develop a personalised treatment plan for you.