A tendon is a tough band of fibrous connective tissue that binds a muscle to the bone and is meant to withstand tension. The source of pain from tendinosis is controversial. At first doctors believed it was a chronic tendon injury and used the term "tendinitis" to describe it. However, recent discoveries have not found inflammation in the tendon and doctors have switched to the term "tendinosis."
Over Use
According to Caring Medical, tendinosis is most often a result of the repetitive use of a joint or tendon over time. For instance, you can develop tendinosis from a repetitive motion at your job, such a typing or working the same machinery all day. You may develop the symptoms from a recreational sport, such as tennis or golf, in which the tendon is aggravated by combining repeated motion with force. If you work a piece of machinery that vibrates all day, this also causes repetitive motion and can cause a tendinosis. Sports that can commonly cause this problem are baseball, basketball, bowling, golf, running, swimming and tennis.
Poorly Fitting Equipment
Athletes who suffer from tendinosis may be using poorly fitting equipment that doesn't support the action required and pushes the athlete to use the limb in an awkward position. According to the Athletic Advisor, these subtle biomechanical changes can be caused from poorly fitting shoes, improper racquets or poorly developed training regimens. If you participate in any sporting activity, ensure your future health and ability to continue to play by using sports equipment that is properly measured and fitted to your size.
Infection and Joint Disease
Occasionally, an infection along the sheath that covers the tendon will cause tendinosis, after an initial inflammation from the bacteria. This tendon sheath can also be affected by other chronic diseases in the body, such as rheumatoid arthritis, gout, scleroderma, Reiter's syndrome, thyroid disease or diabetes. In rare cases, a cut or puncture wound on the skin over the tendon leads to infection. In other cases, the infection can spread from other parts of the body and infect the sheath that surrounds the tendon.
Sudden Injury
When a tendon is injured or the tendon or collagen begins to degenerate, it no longer is able to offer dynamic support of the joint. Another cause for tendinosis is damage to the ligament system. Ligaments are fibrous tissues that bind bone to bone to help form a joint. When the ligaments are weakened, the joint becomes unstable and places more stress on the tendons. Sudden injuries that cause tendinosis can be the result of a sports injury or even a trip down the stairs.
Genetic Predisposition
A genetic predisposition isn't a direct cause of tendinosis but a contributing cause for a specific group of individuals. According to Tendinosis.org, your genetics can make the tendons more prone to injury. If you have a higher than normal Type III/Type I collagen ratio in the tendons, you are more prone to tendon overuse problems and have a more difficult time healing.
