Expert diagnosis and management of common upper limb conditions

The Shoulder

How it Works

The shoulder has the largest range of movement of any joint in the body.  The shoulder blade moves on the chest wall.  The humerus (arm bone) forms a ball and socket joint with the shoulder blade. The ball, or head of the humerus, is quite large and the socket relatively small and shallow.  The head is stabilised in the socket by the rotator cuff.  The rotator cuff is made up of the tendons of four muscles which are attached deep on the shoulder blade.  The muscle that rests on top of the humeral head and shoulder blade is known as the supraspinatus.  It is most at risk of wear against the point of bone on the shoulder blade known as the acromion.  This wear will occur when the muscles of the rotator cuff do not control the head of the humerus in the socket well enough with  use of the arm away from the body.


Postural Control

The shoulder blade floats freely in a sling of muscle from the chest wall, apart from the strut of the collarbone which comes off the sternum anteriorly.  Minor or major injury can upset the brain’s automatic control of the shoulder blade on the chest wall.  A longstanding focus of irritability in the shoulder in particular can prevent the brain from providing the normal support for the postural muscles.  We see this frequently as a difference in position of the shoulder blade on the chest wall when compared to the normal side.  Correcting the source of irritation and then re-establishing the normal postural control of the shoulder girdle can be challenging.


Injury or fatigue of the rotator cuff muscles can lead to poor control of the humeral head and wear of the supraspinatus against the acromion.  This is appreciated as pain over the outside of the shoulder through an arc when the arm is loaded away from the body.  Repetitive use of the arm at and above chest height is a common cause.

The cornerstone of treatment of this condition is to understand the mechanics and avoid loading the arm with the elbow away from the body.  The irritation to the tendon will settle with time but may require a cortisone injection.  At this stage, it will be possible to build control of the shoulder blade on the chest wall and then strengthen the short muscles of the rotator cuff selectively through a carefully supervised program of exercises.  Whilst this sounds simple, if the exercises are performed inexpertly, they may aggravate your condition.  Your physiotherapist will tailor a specific program for you individually.

Occasionally it is not possible to restore good control to the ball and socket.  In this case, surgery may be appropriate.  Your surgeon may recommend an arthroscopic acromioplasty.


Rotator Cuff Tear

Injury or fatigue of the rotator cuff muscles can lead to poor control of the humeral head and wear of the supraspinatus against the acromion.  This is appreciated as pain over the outside of the shoulder through an arc when the arm is loaded away from the body.  Repetitive use of the arm at and above chest height is a common cause.

Where this wear of the rotator cuff is ongoing, pain tends to wax and wane in proportion to load.  Eventually it is possible to wear a hole in the tendon. This is known as a rotator cuff tear. Less commonly, a violent injury may cause a rotator cuff tear in a normal tendon but usually a less violent injury aggravates an existing tear.

The pain from a rotator cuff tear and impingement syndrome are similar.  Where the tear becomes very large, there may be a specific weakness, however typically the presentation is with a painful arc and night pain.

The conservative management of rotator cuff tear is possible because usually a large proportion of the rotator cuff remains intact and this may compensate for the loss of the torn segment.  Therefore, selective strengthening of those remaining fibres may allow the shoulder to re-gain control and restore good function.  With the passage of time however, the rotator cuff tear will increase in size.

If your pain or poor function is severe, your surgeon may recommend surgery.



There are many types of arthritis.  The three most common are osteoarthritis, post traumatic arthritis and cuff tear arthropathy:

Primary osteoarthritis of the shoulder results from slow degenerative change in the shoulder joint and is related to the ageing process.  Over time, cartilage on the joint surface becomes roughened and loses its lubrication properties.  This can often result in stiffness and pain in the shoulder region.

Post-traumatic arthritis results from trauma to the shoulder region.  This may involve a fracture or damage to the joint surface of the shoulder at the time of injury.  Recurrent dislocations of the shoulder can also cause shoulder damage and destruction.

Cuff Tear Arthropathy (arthritis)

This is a combination of:

  1. An ineffective and torn rotator cuff

  2. Loss of central position of the shoulder joint with migration of the head of the humerus upwards

  3. Degenerative changes in the shoulder joint, resulting from 1 and 2 above.

Not all people who have a rotator cuff tear will develop arthritis.  It is only a certain portion of the population who have shoulders which are unable to function correctly after a tear in the rotator cuff who will develop this problem.


Frozen Shoulder

Frozen shoulder is a common condition which can occur in middle age.  Its cause is unknown but interestingly it is more common in diabetics.  It causes the normally loose bag that holds the ball in the socket to become inflamed and thickened.  This results in severe pain as the bag is stretched with movement towards the end of range.  The process leads to progressive stiffening of the shoulder followed by a gradual easing of discomfort and then eventually resolution to a normal shoulder.  Diagnosis early before restriction of movement can be difficult.  Paradoxically, the more the patient fights the “freezing”, the quicker this condition will resolve.  It can however take up to two years.

Before commencing a program of treatment for frozen shoulder, it is crucial that the diagnosis is confirmed, but then we encourage activity and formal stretching exercises with reliably good results.  Not infrequently, an injection of cortisone into the joint can be of dramatic assistance.  Review from your therapist every few weeks can make a big difference to your experience.

Very rarely your surgeon may recommend surgical intervention.



Shoulder Trauma is a common occurrence in young people who participate in an active sporting lifestyle, as well as during everyday life as the result of accidental injury.  A broad spectrum of injury patterns can occur.  These may be minor, in which case simple pain relief and physiotherapy can be of great benefit, or they can be major and require surgery to get the best result.

The two links below provide very helpful information about a range of shoulder injuries: