3) Limitation of movements
The range of motion is severely affected in patients with arthritis. As a part of their condition, the articular surface is damaged by inflammation, the tendons and joints are swelling, and the supporting structures are changing due to chronic disease. In some cases, there is also joint effusion, or an accumulation of liquid inside the joint. Together, these features trigger a reduced range of motion of the affected joint.
Moreover, in some cases, patients have fibrosis of the muscles or tendons, which results in flexion contractures. Thus, there are different mechanical factors through which patients reduce their mobility, and pain is another factor since it triggers avoidance behaviors.