To function appropriately the shoulder joint relies heavily on a group of muscles called the rotator cuff. The rotator cuff comprises four individual muscles:
- Teres minor
When worked individually, these muscles have specific functions. The supraspinatus works to initiate movement of the arm away from the side. The infraspinatus and teres minor work to externally rotate the shoulder. Subscapularis works to internally rotate the shoulder.
The subscapularis attaches to the front of the shoulder blade and the other muscles of the rotator cuff to the top and front of the shoulder blade. This anatomy provides a sling system around the shoulder joint. When all of the muscles of the rotator cuff are contracted together this provides additional stability.
In addition to their regular workload, additionally, it is thought that the bony roof to the shoulder joint formed by the collar bone and acromion of the shoulder blade may compress and shear the tendons of the rotator cuff during certain overhead movements.
The combination of heavy workload and this possible sub acromial impingement during overhead movements make this group of muscles and tendons susceptible to tears and persistent tendinopathy. With it’s location directly under the roof of the shoulder, the supraspinatus tendon has a particular vulnerability.
The tendons of the rotator cuff may suffer tears which can be a significant problem for some individuals. Shockwave therapy will not be considered in these cases as the mechanical energy has the ability to weaken the tendon tear further.
The majority of rotator cuff related shoulder pain is caused by what doctors and physiotherapists term a tendinopathy. Evidence currently points to a tendinopathy developing due to a failing healing response within the body of a tendon and several anatomical changes may develop as a result. The first is an increase in blood vessels known as neovascularisation. The second is a disorganisation of the fibres in the tendon known as collagen. The third is the deposition of ground substance, or calcific deposits within the tendon.
It is currently thought that shockwave therapy is best reserved for cases of persistent tendinopathy with significant calcific deposition.
Shockwave therapy, sometimes referred to as extracorporeal shockwave therapy, is a treatment which has seen a rapid growth in recent years within musculoskeletal and orthopaedic clinical practice.
Mechanical energy delivered to tissues for diagnostic purposes or to deliver therapeutic doses have been utilised for decades in healthcare. Most of these procedures are known as ultrasound diagnostic or therapy by members of the public. Ultrasound is essentially acoustic waves beyond the frequency which the human ear can detect and when delivered to tissues will generally not be felt by the patient.
Shockwave therapy uses the same principle of delivering mechanical energy to tissues but a shock wave is a far stronger wave form than ultrasound. The aim of shockwave therapy is two fold when targeting the shoulder’s rotator cuff tendons.
Firstly, the shockwave is designed to cause micro-inflammation in the targeted area of the rotator cuff tendon. It is thought that this is able to reset the full healing process. Following the inflammatory phase the rotator cuff tendon will then be able to regenerate new tendon tissue and organise it’s fibres in an appropriate orientation.
Secondly, the mechanical waves may be used to break down calcific ground substance deposits within the rotator cuff tendon which may be the source of pain for many individuals.
Prior to commencing any treatment our expert orthopaedic shoulder consultant or physiotherapist will discuss the intended benefits versus potential complications in your individual circumstance. Full details of possible side effects and precautions to undergoing shoulder shock wave therapy are best read here
Following this discussion, a shoulder shockwave therapy treatment plan will be devised. This may involve three to five sessions of shock wave treatment. Each session will be spaced appropriately according to symptoms and any post treatment discomfort to allow the rotator cuff tendons to settle in preparation for the next session.
The procedure itself lasts approximately five to ten minutes. Your consultant or physiotherapist will scan the shoulder to reassess the structure of the rotator cuff tendon. This information and your clinical examination will determine the precise area of the tendon to target and angle of approach with the shock wave probe. Normally, calcific deposits are located within the body of the supraspinatus tendon but the probe may be placed on on the back, side or front of the shoulder region according to the targeted region and clinical preference of the treating clinician. Once the probe has been positioned, your clinician will deliver the treatment after checking you are comfortable and ready.