CLASSIFICATION OF JOINTS
A. IMMOVABLE JOINT; THEY ARE OFTEN CALLED FIXED JOINTS, AND ALLOW NO MOVEMENT BETWEEN BONES. These joints are interlocked and held together by Connective Tissue, or they are fused together. The places where the bones of the SKULL meet (SUTURE) meet are examples of immovable joints.
B. SLIGHTLY MOVABLE JOINT (SEMI MOVABLE JOINTS) These joints permit a small amount of movement. These bones are farther apart from each other than immovable joint bones. The joints between the two bones of the lower leg (TIBIA and FIBULA) and the joints of the vertebrae are examples of slightly movable joints.
C. FREELY MOVABLE JOINT.Ê MOST OF THE JOINTS OF THE BODY ARE FREELY MOVABLE JOINTS. In Freely Movable Joints, the ends of the bones are covered with a layer of Cartilage that provides a smooth surface at the joint.
TYPES OF FREELY MOVABLE JOINTS
A. BALL AND SOCKET JOINT - Permits circular movement - the widest range of movement.Ê THE SHOULDER Joint, which enables you to move your arm up, down, forward and backward, as well as to rotate it in a complete circle.
B. HINGED JOINT - Permits a back-and-forth motion.Ê The Knee enables your leg to flex and extend. The Elbow, which allows you to move your forearm forward and backward.
C. PIVOT JOINT - Permits rotation of one bone around another.Ê The elbow enables your hand to turn over. It also allows you to turn your head from side to side.
D. GLIDING JOINT - Permits a sliding motion of one bone over another.Ê Found at the ends of the collarbones, between wrist bones, and between anklebones.
E. SADDLE JOINT - Permits movement in two planes.Ê This type of joint is found at the base of the thumb.
F. ELLIPSOID JOINT - Allows for a hinge type movement in two directions.Ê The joints that connect fingers with the palm and toes with the soles of feet are examples. Ê
The Human Skeleton is homologous to skeletons of other animals. Once you learn the bones in a human, you can identify the bones in other animals.