Tendonitis is an inflammatory (swelling) disease of the tendons. Tendons are tough but flexible bands of fibrous tissue that connect the muscles to the bones. If the tendon becomes swollen, it will become irritated by the action of the muscles and movement will be painful.
Types of tendonitis
Tendon inflammation can occur in any tendon in the body, especially in the ankle (Achilles or posterior tibia tendon), wrist, kneecap, elbow or shoulder. Here are the most common types of tendonitis:
- Achilles tendonitis – Common in runners, Achilles tendonitis is often caused by overuse of the tendon that connects the calf muscles to the heel bone. Symptoms of this condition include heel pain and heel tenderness.
- Peroneal tendonitis – Inflammation of the peroneal tendons is usually caused by repetitive ankle motion. Common symptoms of peroneal tendonitis include pain at the back of your ankle, pain that worsens during activity and lessens during rest, pain when rotating the foot, swelling at the back of the ankle, and unstable ankle when carrying objects
- Patellar tendonitis – Also known as jumper's knee, this condition refers to the inflammation of the patellar tendon, which connects the patella or kneecap to the tibia or shin bone. This is caused by overuse of the knee joint. Repeated stress can cause the tendons to be inflamed. Symptoms include pain and tenderness around the patellar tendon, swelling, pain when jumping, running, walking, bending or straightening the leg.
- Posterior tibial tendonitis – This condition affects the tendon that connects the back of the shinbone to the bones of your foot. Common symptoms of posterior tibial tendonitis are pain on your foot, difficulty in pointing toes inward, tendon swelling, and the inability to stand on tiptoes. If left untreated, this can lead to flatfoot in the long run.
- Rotator cuff tendonitis – This affects the tendons that help move the shoulder joint. This can result from engaging in activities that involve repetitive lifting of the arm over your head. Rotator cuff tendonitis can also occur when you keep your shoulder in one position for a long period or when you frequently sleep on your shoulder at night.
- Tennis elbow – This tendon inflammation causes pain around the outside of the elbow. It is often a result of overuse of the forearm muscles and tendons.
- Wrist tendonitis – The inflammation of one or more tendons in the wrist causes symptoms like stiffness, pain, swelling or warmth in the wrist. The wrist tendon can be inflamed due to small tears that resulted from sudden or repetitive injury.