Joints, HBS 4.1.1 and 4.2.1

Saddle Joint

One bone is a "saddle", the other is the "rider", provides movement and stability. Examples include the carpometacarpal joint of the thumb.

Ball and Socket Joint

Partially spherical joint head lies within a socket, allowing movement and rotation. Examples include the hip joint.

What is ROM?

Range of motion

Freely movable joints are...?

Synovial

Plane Joint

Also called planar or gliding, two bones meet at a flat surface and glide over each other in any direction. Examples include the metacarpals and metatarsals.

What is synovial fluid?

A liquid found in the cavities of joints that is the consistency of egg whites. It lubricates bones to prevent friction and increase mobility.

What is cartilage?

A smooth, resilient tissue that joins joints. This material also forms growth regions in the body, and offers less movement than synovial fluid.

Condyloid Joint

Allows movement in two planes by a joint head fitting into an elliptical cavity. Examples include the base of the index finger, or the connection of the radius and carpal bones.

Pivot Joint

Allows movement via pivoting around a single axis. Examples include the joint between the first and second vertebrae.

Where are freely movable joints found?

Appendicular skeleton, for movement and flexibility

Where are immovable/partially movable joints found?

Axial skeleton, for protection and stability

Partially movable joints are...?

Cartilaginous

ROM: Circumduction

Circular movement while limb remains facing stationary

What are ligaments?

Connects bone to bone to stabilize connection points, prevents movement that could damage bones.

What are tendons?

Connects muscle and bone, made of collagen, withstands tension. Regulates forces between muscle tissues to maintain stability.

ROM: Flexion

Decreases angle between body parts

ROM: Adduction

Movement towards the body's midline

ROM: Depression

Downwards movement

Immovable joints are...?

Fibrous

What tool is ROM measured with?

Goniometer

ROM: Extension

Increases angle between body parts

What role do joints play?

Joints are places where two bones meet. They allow flexibility and movement as well as provide support to the skeleton.

ROM: Abduction

Movement away from the body's midline

ROM: Dorsiflexion

Movement of the foot that brings toes away from the sole

ROM: Plantar flexion

Movement of the foot that brings toes to the sole

Classification of joints via function

This type of classification denotes how much movement a joint allows. These include immovable, partially movable, and freely movable.

Classification of joints via structure

This type of classification denotes what the joints are made out of. This includes fibrous joints, cartilaginous joints, and synovial joints.

ROM: Rotation

Turning around an axis

Hinge Joint

Two or more bones can flex or extend along a single axis. Examples include the ankle, knee, or elbow.

ROM: Elevation

Upwards movement