The rotator cuff is comprised of four small muscles deep within in the shoulder that hold your arm bone in the shoulder socket. These muscles also contribute to the inward and outward rotation of your arm.

Your Achilles tendon is the tendon that connects your calf muscle to your heel bone. Its function is to raise your heel off the ground to assist with walking, running or jumping.

Facet joints are located between each vertebrae in your spine. They function to connect the vertebrae, as well as allow you to bend and twist your spine. Sometimes, the joint can become irritated, inflamed and painful. Pain that originates in your facet joint is known as facet joint syndrome.

Learn about the various diseases that affect the tendons, including tendinosis, tenosynovitis, and enthesopathy. Understand their symptoms, diagnosis, and treatment options to manage tendon pain effectively.

Lumbar fusion is surgery in which your surgeon fuses two vertebrae in the lumbar region -- the lower back. If you have a spinal misalignment, tumors or weakness that is causing pain or discomfort, your doctor might recommend a lumbar fusion to treat the problem.

Tennis elbow, or lateral epicondylitis, is a type of tendonitis that affects the tendons that join the outside of the elbow with the muscles of the forearm. It typically develops in response to overuse of the elbow and may cause significant pain, explains the American Academy of Orthopaedic Surgeons.

Injuries from exercise can happen instantly or slowly. You don’t have to have a sudden traumatic injury to tear your rotator cuff; you can gradually develop a rotator cuff tear as a result of overuse or wear and tear.

Although the wear-and-tear type of arthritis, or osteoarthritis, is much more common than rheumatoid arthritis, both frequently affect the hands.

Thumb tendinitis can make daily tasks that are normally taken for granted difficult. You may have pain while writing, typing or texting on your phone. Thumb tendinitis is typically caused by overuse of the muscles that move your thumb.

Hammer toes are caused when the tendons on the top and the bottom of the toe contract or become rigid. Typically, the second toe is most likely to be bent and to suffer from hammer toe syndrome.

There are two common reasons that may explain why your left Achilles tendon hurts first thing in the morning -- injury or positioning. If you participate in sports or are physically very active, you may have an overuse tendinopathy -- a condition that causes micro-tearing of fibers in the tendon.

Arthritis is the leading cause of disability in the United States, states the American Academy of Orthopedic Surgeons (AAOS). Exercising your arthritic ankle will protect your joint health. Exercises will help keep your ankle joint lubricated, increase your blood circulation and improve your muscle functioning.