Joints are present at every point in the body where two bones come together, and are instrumental in providing flexibility and producing movement in the body. In addition to flexibility, joints are responsible for creating stability and maintaining an appropriate range of motion during certain activities. Because they are the focus of all musculoskeletal movements, joints are prone to pain and stiffness as occurs in arthritis.
Different types of joints are involved in various movements, and thus are more or less likely to develop joint pain from arthritis. For instance:
- The bones of the skull come together at fixed joints that are incapable of producing movement. So while they are technically joints, these articulations do not develop joint pain related to movement.
- The bones of the upper back (thoracic spine), where the ribs are attached to the thoracic vertebrae, provide strength to the skeleton and are less important in movement. Thus, these joints are less often the source of pain.
- The bones of the shoulders, hips, knees, and smaller joints in the neck and lower back (cervical and lumbar spine, respectively) are all comprised of highly flexible joints that are responsible for regular movements such as walking, running, standing, sitting, and moving the arms. These are the joints that are most likely to generate pain.
Joints that bear more body weight are more likely to develop osteoarthritis. Due to their location, the hips and knees are responsible for bearing much of the body’s weight, in addition to their high degree of flexibility. In general, joints that are flexible and weight bearing are the most likely to develop joint pain due to osteoarthritis.