Stiffness is the feeling that the motion of a joint is limited or difficult. The feeling is not caused by weakness or reluctance to move the joint due to pain. Some people with stiffness are capable of moving the joint through its full range of motion, but this movement can require force. Joint stiffness caused by inflammation usually occurs or is worse immediately after awakening or after prolonged resting or immobility. Stiffness is common with arthritis. Morning stiffness commonly occurs with rheumatoid arthritis and other types of inflammatory arthritis and gradually lessens with activity after an hour or longer. Stiffness that gets worse as the day progresses is usually not caused by inflammation.
Doctors can sometimes diagnose the cause of stiffness by the person's other symptoms and the results of a physical examination. Different types of arthritis may affect different joints. How long stiffness lasts can also be a clue. For example, if stiffness lasts for less than 15 minutes, the joint is probably not inflamed. The person is examined to make sure that the problem is not due to pain with motion or weakness. Doctors examine the muscles as well as the joints to make sure that the problem is not muscle rigidity as occurs in Parkinson disease or muscle spasticity that occurs in strokes and spinal cord disorders. Because inflammatory arthritis is often the cause of joint stiffness, blood tests (for example, to look for levels of rheumatoid factor) and x-rays or ultrasonography may be done.
Stiffness is relieved by treating the disorder causing it. Stretching, physical therapy, and taking a hot shower after waking may relieve stiffness and improve the ability to do activities.
In trigger finger, a finger becomes locked in a bent position. The finger locks when one of the tendons that flex the finger becomes inflamed and swollen. Trigger finger is caused by which of the following?