Definition: Human joints are formed when the ends of two bones come together. The joints hold the bones together and allow for movement of the skeleton.
All of the bones, except the hyoid bone in the neck, form a joint. Joints are often categorized by the amount of motion they allow. Some of the joints are fixed, like those in the skull, allow for no movement. Other joints, like those between the vertebrae of the spine, allow for some movement. Most of the joints are free moving synovial joints. Arthritis can affect any type of joint, but these joints are the most affected.
Some of the common joints affected by arthritis and joint pain are:
Saddle Joint: This type of joint allows for back and forth and side to side motion but limited rotation. There is a saddle joint in the thumb.
Also Known As: articulation
Common Misspellings: joynts, jionts
Examples: The hip is a ball-and-socket joint.
Joint Index, Wheeless' Textbook of Orthopaedics