Joints and their Movements

Protraction

Moving a part forward (thrusting the chin forward).

Circumduction

Moving a part so that its end follows a circular path (moving the finger in a circular motion without moving the hand).

Adduction

Moving a part toward the midline (returning the lower or upper limb from the horizontal position to the side of the body).

Elevation

Raising a part (shrugging the shoulders).

Extension

Straightening parts at a joint so that the angle between them *increases* and the parts *move farther apart* (straightening the lower limb at the knee).

cartilaginous joints

allow only slight movement and consist of bones connected entirely by cartilage

synovial joints

freely movable joints

Fibrous joints

immovable Examples: bones on skulls (sutures), teeth sockets, and distal joint between the tibia and fibula

Flexion

Bending parts at a joint so that the angle between them *decreases* and the parts come *closer together* (bending the lower limb at the knee).

Dorsiflexion

Bending the foot at the ankle toward the shin (bending the foot upward).

Plantar flexion

Bending the foot at the ankle toward the sole (bending the foot downward).

Ball & Socket Joint

Consists of a bone with a globular or slightly egg-shaped head that articulates with the cup-shaped cavity of another bone. Such a joint allows a wider range of motion than does any other kind, permitting movements in all planes, as well as rotational movement around a central axis. Example: Shoulder & Hip Movement: Flexion/Extension/Adduction/ Abduction/Internal & External Rotation

Hyperextension

Excess extension of the parts at a joint, beyond the anatomical position (bending the head back beyond the upright position).

Saddle Joint

Forms between bones whose articulating surfaces have both concave and convex regions. The surface of one bone fits the complementary surface of the other. This physical relationship permits a variety of movements, mainly in two planes. Example: Joint of the thumb Movement: Flexion/Extension/Adduction/ Abduction/Circumduction

Depression

Lowering a part (drooping the shoulders).

Rotation

Moving a part around an axis (twisting the head from side to side). Medial rotation involves movement toward the midline, whereas lateral rotation involves movement in the opposite direction.

Abduction

Moving a part away from the midline (lifting the lower or upper limb horizontally to form a right angle with he side of the body).

Retraction

Moving a part backward (pulling the chin backward).

Planar (gliding) joint

The articulating surfaces are nearly flat or slightly curved. These joints allow sliding or back-and-forth motion and twisting movements. Example: Most of the joints within the wrist and ankle (Intercarpal joints) The sacroiliac joints and the joints formed by ribs 2 though 7 connecting with the sternum are also gliding joints. Movement: Gliding movements

Hinge Joint

The convex surface of one bone fits into the concave surface of another. Such a joint resembles the hinge of a door in that it permits movement in one plane only. Example: Elbow & knee Movement: Flexion/Extension

Pivot Joint

The cylindrical surface of one bone rotates within a ring formed of bone and fibrous tissue of a ligament. Movement at such a joint is limited to rotation around a central axis. Example: Top of neck (atlas and axis bones) Elbow (proximal ends of the radius and the ulna) Movement: Rotation of one bone around another

Condyloid joint

The ovoid condyle of one bone fits into the elliptical cavity of another bone. This type of joint permits a variety of movements in different planes; rotational movement, however, is not possible. Example: Wrist/MCP & MTP joints. Joints between the metacarpals (bones of the palm) and phalanges (bones of the fingers and toes). Movement: Flexion/Extension/Adduction/ Abduction/Circumduction

Eversion

Turning the foot so the sole faces laterally.

Inversion

Turning the foot so the sole faces medially.

Pronation

Turning the hand so the palm is downward or facing posteriorly (in anatomical position).

Supination

Turning the hand so the palm is upward or facing anteriorly (in anatomical position).