anatomy joints

Gliding (Plane) Joint

→ Flat bone surfaces slide over each other; side-to-side or back-and-forth movement

→ Example: wrist (intercarpal), ankle (intertarsal)

Hinge Joint

→ Allows movement in one direction (flexion and extension)

→ Example: elbow, fingers

Pivot Joint

→ Allows rotation around an axis

→ Example: radius and ulna at the elbow, neck

Condylar (Ellipsoid) Joint

→ Allows flexion, extension, abduction, and adduction

→ Example: wrist

Saddle Joint

→ Allows flexion, extension, abduction, adduction, and opposition

→ Example: thumb

Ball-and-Socket Joint

→ Allows rotation, flexion, extension, abduction, and adduction

→ Example: shoulder, hip

Isotonic Contraction

→ Muscle changes length and causes movement

→ Example: lifting a box, push-ups

Isometric Contraction

→ Muscle does not change length; no movement occurs

→ Example: plank, holding posture

Synarthroses

→ Non-moving joints

→ Example: skull

Amphiarthroses

→ Slightly movable joints

→ Example: pubic symphysis

Diarthroses

→ Freely movable joints

→ Example: knee, elbow

Fibrous Joints

→ Bones connected by dense connective tissue; mostly immovable

→ Example: sutures, syndesmoses, gomphoses

Cartilaginous Joints

→ Bones connected by cartilage; slightly movable or rigid

→ Example: intervertebral discs, sternum to rib

Synovial Joints

→ Bones connected by capsule and fluid-filled cavity; freely movable

→ Example: shoulder, hip

Flexion

Decreases the angle between two bones

Extension

Increases the angle between two bones

Abduction

Movement away from the midline

Adduction

Movement toward the midline

Rotation

Turning a bone around its axis

Circumduction

Moving a limb in a circular motion

Elevation

Lifting a body part upward

Depression

Lowering a body part

Protraction

Moving a body part forward

Retraction

Moving a body part backward

Dorsiflexion

Lifting the foot upward at the ankle

Plantarflexion

Pointing the foot downward

Inversion

Turning the foot toward the midline

Eversion

Turning the foot away from the midline