Tendonitis is considered an overuse injury caused by repetitive loading of a tendon exceeding the ability of the tendon to handle the load. Repetitive loading of a tendon can breakdown otherwise normal tissue resulting in pain, swelling, and decreased functional ability of the associated joint.
Common causes of tendonitis include the following:
• Excessive increases in training load, distances, and speed
• Mechanical errors from improper technique
• Structural abnormalities
• Inappropriate equipment, play or work conditions
• Training surfaces (surfaces that do not give)
• Muscle imbalances
• Inadequate time for tendon recovery
What happens to the structure of the tendon when it is overloaded?
The initial response of the tendon is inflammation. In fact, when you break down the word tendonitis, “itis” means inflammation. Add “itis” to tendon and you have inflammation of a tendon.
Initially, the tendon becomes painful to the touch and begins to weaken. If the tendon is continuously overloaded, the tissue begins to break down.
A number of structural changes can occur during this process including thickening of the synovial sheath surrounding the tendon, areas of abnormal tissue known as fibrosis are laid down within the tendon, thickening of connective tissue, and adhesions (scar tissue laid down in and around the tendon). The longer the condition goes untreated, the more structural changes occur.