Types of Joints and Their Movements

Front

SYNARTHROSIS

Back

No movement. The sutures in Xochitl’s skull keep her brain protected by firmly joining the bones together preventing movement.

Front

AMPHIARTHROSIS

Back

Some movement. When Jason bends slightly forward to pick up a ball, the intervertebral discs between their vertebrae allow limited bending and twisting motions.

Front

DIARTHROSIS

Back

Freely movable. Jaslyn’s shoulder moves freely in many directions to pitch a softball with power and accuracy.

Front

PIVOT JOINT

Back

Rotation around a single axis. When Chinaza shakes her head 'no,' the joint between her first 2 cervical vertebrae allows her head to rotate smoothly side-to-side.

Front

HINGE JOINT

Back

Bending and straightening in one plane. When throwing a fastball, Alex’s elbow bends and straightens like a door hinge to generate force.

Front

CONDYLOID JOINT

Back

Movement in two planes: flex/extend and abduct/adduct. When Rachel spreads her fingers apart and then closes them around a tennis ball, her knuckles move in two directions to grip effectively.

Front

SADDLE JOINT

Back

Both articulating bone surfaces have complementary shapes: curved inward (concave) along one axis and curved outward (convex) along the perpendicular axis. When Amir grips the uneven bars, the base of his thumb moves in multiple directions—curving and rotating—to provide a strong, flexible hold essential for swinging and supporting body weight.

Front

PLANE JOINT

Back

Sliding or gliding motions. When Drew swings a bat during a baseball game, his wrist bones slide past each other smoothly to control the bat’s motion.

Front

BALL-AND-SOCKET JOINT

Back

Movement in all directions including rotation. During a soccer match, Aurora’s hip joint rotates and moves forward, backward, and sideways, allowing her to sprint and change direction quickly on the field.