Tendons are the things that attach your muscles onto your bones. They are generally quite tough and very smooth. They need to be able to move easily so that they can pull on the joint as your muscles contract.
Tendonitis means inflammation of the tendon. The damage is usually caused by overloading the area too much or to suddenly.
Tendonosis is degeneration of the tendon’s collagen. It is usually caused by long term overuse. And lack of rest.
Tenosynovitis – this is inflammation of the tendon sheath. This usually starts with irritation of the tendon itself.
The terms tendonitis and tendonosis are often misused. If you want to know more about the differences between the two have a look at this research paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3312643/
Tendonosis, tendonosis and tenosynovitis can be a symptom of another problem; of poor mechanics elsewhere that are causing unusual pressures and strains on the tendon.
For example: tennis elbow will give you pain in the tendon itself, but is sometimes caused by poor movement in the shoulder.
If you’ve got tendonitis think hard about what activities you are doing that might be aggravating the problem.
Treatment usually involves ice and rest to reduce the inflammation and allow the area to repair, plus soft tissue treatment to the area. A manual therapist will also look to find the underlying cause and might treat problems away from the injury to help prevent the pain from coming back.
Remember that tendinitis means the tendon is inflamed and probably needs ice on it. Jay Sheridan (Sports Therapist)