To understand a rotator cuff tendon tear and it’s causes, it is necessary to appreciate the function of a rotator cuff tendon. The cuff tendons are a group of four muscles, the individual tendons of which, work together as the “rotator cuff.”
Essentially, the cuff is a single unit but it is made up of the tendons of four muscles.
- teres minor
The cuff has two basic functions – arm movement and shoulder stability.
Movement– The cuff muscles are comparatively small muscles whose principal role is to get the arm moving. Once in motion other larger, surrounding muscles such as the deltoid take over.
Stability– The tendons work collectively to stabilise the shoulder. They hold the humeral head of the upper arm bone and maintain it tight to the scapula (shoulder blade).
Classifications of a rotator cuff tendon tear
A tear is most often referred to by cause and size.
Size can be
- full thickness tear – tendon torn through its whole width
- partial tear – tendon frayed but not torn completely through
- large tear
- small tear
Cause can be classified as
- Chronic – overuse injury or a gradual loss of muscle strength
- Acute – single identifiable incident
- Mix of both – chronic degeneration followed by an acute injury
Why does a rotator cuff tendon tear?
The vast majority who suffer a tear in rotator cuff tendons are over 40 years of age. The tendons simply lose function with age. We also become less active and they weaken as a consequence of being underused.
The human body, with advancing age, becomes less capable at repairing damage on a molecular level. Tendinopathy type injuries are often the result. This weakening related injury transforms into a sequence of steady decay that leads to more and more problems.
This alone, may be enough to cause a tear in the tendons but there is often another factor to be considered. The cuff weakens so it fails to provide the stability required by the shoulder. The Humerus can move excessively and “ride up” from the scapula. This will cause the tendons to become compressed. They begin to rub against the clavicle above and over time tear as a result.
A complete tear is frequently linked with a combination the process outlined above and an acute incident. This process more often results in a partial rotator cuff tendon tear. Join me to discover more.