Shoulder ‘Impingement’ – What you need to know

‘Shoulder Impingement’ also often referred to as rotator cuff tendonitis, throwers shoulder, subacromial bursitis, subacromial impingement, swimmers shoulder. Regardless of which term you use the anatomy & often underlying biomechanical cause is similar across many of the above diagnosis.

Let’s quickly re-visit the anatomy of the shoulder; a ball and socket joint. Likened to a golf ball sitting on a tee which highlights the ‘unstable’ nature of the joint having a big head (humerus) sitting in a small socket (glenoid). The socket is deepened by a rim of cartilage called the labrum which along with the capsule formed by thick bands of ligaments adds a little bit of stability to the joint.  The next layer is the rotator cuff. The Cuff is a group of 4 muscles; supraspinatus, infraspinatus, subscapularis and teres minor. Their role is exceptionally important, forming a ‘cloak’ around the head of the humerus, depressing it down and essentially helping to hold the shoulder snugly in its socket.

Movement of the shoulder joint requires a balance of stability & mobility not only at this ball and socket joint but also co-ordination of movement of the shoulder blade (scapula) as it rotates around the rib cage and adequate mobility of the thoracic spine. Slight dysfunction in one of the above can result in a breakdown of the correct movement pattern of the shoulder which eventually can cause pain.

Patients present with a deep ache in their shoulder that can sometimes be hard to actually pinpoint. Often day to day activities that take place below the level of the shoulder are symptom free, while movements overhead or positions that require rotation can cause pain. For women this can be doing up their bra or for men reaching into their back pocket. Sleeping on the affected side is painful. The severity can vary from a background niggle to those that can barely lift their arm above shoulder height.

Pain in these clients is often attributed to a pinching or impingement of the supraspinatus tendon. This is one of the 4 rotator cuff muscles mentioned above. It passes through the subacromial space which sits between the acromion and head of the humerus (see picture). When our shoulder complex is functioning efficiently the tendon passes through this narrow tunnel with no problems. Problems arise when changes in our biomechanics, due to weakness, stiffness or trauma causes this space to narrow slightly compressing the tendon resulting in inflammation & pain.

A skilled physiotherapist will usually be able to diagnose ‘shoulder impingement’ based on your history & clinical presentation. Further investigation such as ultrasound or MRI may be required if conservative management doesn’t give relief or to explore other possible injuries.

The most important reason why you need should get your physio involved is to look for the underlying cause of your shoulder pain. Is it related to bad posture? Stiffness in the mid to upper back or a forward shoulder position can predispose you to poor shoulder movement patterns. Repetitive overuse with bad
biomechanics is a recipe for injury and we tend to see this in alot of our clients. A slightly rounded shoulder, forward neck position and weakness in the mid back places the shoulder in a sub-optimal position before movement has even started.

Or was there a trauma? A fall onto the point of the shoulder, a big hit in footy?

Finding the cause will guide the direction of treatment & appropriate management.

Treatment will often involve a combination of hands on techniques including soft tissue releases & dry needling to address tight overactive muscles along with joint mobilisations to target stiffness in the neck and upper back. A rehabilitation program can include mobility exercises using a trigger ball and/or foam roller along with a variety of rotator cuff activation & strengthening exercises to restore efficient movement patterns. Postural education and advice regarding activity modification can also play an important role in the recovery process.

There are some cases where conservative management can fail. DON’T PANIC. There are some more aggressive and invasive options that can be considered such as cortisone or platelet injections or as a worst case scenario surgery. Your physio will guide you in this process if need be.

Shoulder “Impingement’ can be a very debilitating problem. When it’s chronic it’s a frustrating condition to suffer but also a frustrating one to treat as it can be stubborn & slow. Don’t ignore that background niggle for too long, the sooner you address it the better!