In the human body, joints are the crucial skeletal elements that allow movement to take place. Joints are located at the site where two bones meet. The types of joints in the human body are classified by the level of movement they enable and include fibrous, cartilaginous or synovial joints.
Fibrous Joints
Fibrous joints are a type of joint that is classified as immovable, according to Minnesota State University. Joints of this type occur when the bones are separated by a very thin layer of connective tissue. These types of joints are also called synarthrodial or immoveable joints due to the nature of their action. Fibrous joints, such as those that occur between the sutures of the skull bones, do not allow very much movement to occur between the bones and act to hold them together.
Cartilaginous Joints
Cartilaginous joints allow limited movement between bones to occur, according to the National Institute of Standards and Technology. Joints of this type, which are also called ampthiarthrodial or partially moveable joints, occur where bones are connected by fibro cartilage (hyaline cartilage). Cartilaginous joints, such as those that occur between the ribs and the sternum, allow some flexibility of movement while providing strong support. The joints between the vertebrae of the spinal column are also an example of a cartilaginous joint.
Synovial Joints
Synovial joints allow free movement to occur between bones. These types of joints---also called diarthrodial joints--are filled with synovial fluid, which lubricates the joints and helps them to move easily. The University of Minnesota notes that there are six different types of synovial joints within the body: ball-and-socket, condyloid, saddle, pivot, hinge and gliding. The ball-and-socket synovial joint allows for the greatest range of rotational motion and includes the joints of the shoulder and hip. The condyloid synovial joint allows for angular movement, but not rotation. Examples of condyloid joints include the joints of the fingers, toes, hands and feet. The saddle synovial joint occurs between bones that are complementary to each other in shape and allow for a large range of motion, such as the joints of the thumb. The pivot synovial joint allows for rotating or twisting motion to occur and includes the joints of the neck. The hinge synovial joint allows movement to occur in one plane, such as flexion or extension, and includes the joint of the elbows. The gliding synovial joint allows bones to slide or twist, but do not allow circular motion. The carpals of the wrist and the tarsals of the ankle are examples of gliding synovial joints.
