Alongside back pain, shoulder impingement is one of the most common presenting problems in physiotherapy. A patient will present with a clicking/grinding type sensation during specific movements of their shoulder. Typically, these movements are overhead activities, especially during movements around shoulder height. Common sports prone to such issues include swimming, tennis and regular gym goers, and can occur at all ages. This is called a painful arc presentation, whereby pain does not commence until a certain degree of elevation, and also clears above a certain degree of elevation. This causes an “impingement” of the two joint surfaces that make up your shoulder joint. This is the humeral head and the glenoid fossa of the scapula. During elevation based movements around shoulder height, a large bony prominence of the humeral head has to pass under the socket made up by the glenoid fossa. This is called the greater tuberosity. If it doesn’t do so correctly, a catching type sensation is felt as the bone forces itself under the socket, eventually clearing and removing symptoms again.
Strictly speaking, impingement is a symptom and not a diagnosis. Multiple abnormalities can cause this problem. Impingement can result from either an internal or external cause. Internal is the result of an issue within the joint itself, such as bone abnormalities or degeneration. External impingements are far more common and include issues such as muscle weakness or scapulothoracic dysfunction. Further categorisation can be made between primary and secondary impingements. Primary refers to structural abnormalities such as the shape of your joint surfaces or
osteoarthritic changes. Secondary, the more common of the two, refers to dynamic dysfunctions such as muscular imbalances and postural changes. As you can see, impingement is a very complicated symptom requiring specific testing to identify the true cause of the problem.
Impingement can be from an acute injury or more commonly an insidious onset which builds over a period of weeks and months. An acute injury could be a tear of a muscle in the region resulting from heavy lifting. Longer build up is very commonly from weight lifting or other exercise which places the identified region under stress for a prolonged period. This continually irritates structures found within the area of risk, resulting in inflammation and pain during aggravating movements. This area is called your sub-acromial space, containing a bursa and rotator cuff tendons in particular.
Treatment will focus on the underlying cause of your impingement. Usually this is a rotator cuff tendinopathy or partial tear of such muscle. Once acute symptoms have been settled using manual therapy, rehabilitation exercises to strengthen your rotator cuff are a key element to long term prevention. This is due to the stabilising effect and downward force it applies to the humeral head, increasing the space between the two joint surfaces, therefore stopping the irritation at source. In more chronic cases, a steroidal injection can be required to reduce the inflammation within the joint. Further still, if an MRI scan finds significant damage to either the joint or surrounding tendons, arthroscopic surgery can be required.
To conclude, assessment is crucial in impingement based shoulder problems to identify the cause of this symptom, which will then determine the appropriate cause of treatment. Usually such conditions resolve with a degree of rest and appropriate rehab in around 1-2 months. More chronic issues can take longer dependent upon the extent of the underlying injury and what management they require. Either way, it is not an injury that will just pass if you ignore it, they will nag you until you do something about it! It is far better to nip such injuries in the bud early on before getting to the chronic stage. Seek a physiotherapy assessment and this process can begin straight away.