Figure 6.21 Types of synovial joints. first metacarpal Ball-and-Socket carpals ...:::::::l!!:l'ti"'.... Pivot ...- Hinge Types ofSynovial Joints joint between the proximal ends of the radius and ulna, and the joint between the atlas and axis. Different types of freely movable joints are listed here and de- Hinge joint. The conve..x surface of one bone articulates with picted in Figure 6.2L the concave surface of another. Up-and-down motion in Saddle joint. Each bone is saddle-shaped and fits into the one plane is possible. Examples: the elbow and knee complementary regions of the other. A variety of joints. movements are possible. Example: the joint between the Gliding joint. Flat or slightly curved surfaces of bones carpal and metacarpal bones of the thumb. articulate. Sliding or twisting in various planes is Ball-and-socket joint. The ball-shaped head of one bone fits possible. Examples: the joints between the bones of the into the cup-shaped socket of another. Movement in all wrist and between the bones of the ankle. planes, as well as rotation, are possible. Examples: the Condyloid joint. The oval-shaped condyle of one bone fits shoulder and hip joints. into the elliptical cavity of another. Movement in Pivot joint. A small, cylindrical projection of one bone different planes is possible, but rotation is not. Examples: pivots within the ring formed of bone and ligament of the joints between the metacarpals and phalanges. another bone. Only Totation is possible. E;mmples: the 23 . Chapter 6 The Skeletal System .