This is a very common condition and one that is oftan misdiagnosed.
Who gets it? 1. sports people that overuse the shoulder or in which their sport overdevelops a muscle group – which then causes an imbalance in the muscles and leads to the joint developing a poor position in which the SST tendon is being nipped and the bursa becomes swollen or hardened and therefore nips the tendon instead of cushioning it as you raise your arm. Once the bursa becomes inflammed this is known as a BURSITIS and then a vicious circle develops when every time you lift your arm you are squeezing the bursa and nipping the tendon even more…. known as an IMPINGEMENT – in many cases the tendon can’t cope with the nipping and becomes badly damaged – tendonitis or a tearing will develop.
2. non sports people also get this – some for no reason at all – we see a lot of women mid 40’s onwards who have no reason for developing this and perhaps poor posture and lack of exercise has contributed with the age-ing process thinning the tendon.
3. someone who not used to it then embarks on a DIY or project working overhead – such as painting ceilings, cutting hedges etc
a similar cause is someone who goes back to exercise and does too much
4. someone who has a trauma – from a simple slip or fall where they either land badly or use the arm to grab for something to save themselves.