Types of Joints

Uniaxial joints

• Hinge

• Pivot

Hinge Joint

• Ex. IP (fingers), elbow, and knees

• Perform motions of flexion and extension (saggital)

• Uni-axial

Pivot Joint

• Ex. Radioulnar joint

• Performs supination and pronation (transverse)

• Uni-axial

Biaxial Joints

• Condyloid

• Ellipsoid

• Saddle

Condyloid Joint

Spherical convex surface with a concave surface

• Ex. MCP in hands and MTP in feet

• Performs flexion/extension and abduction/adduction

• Bi-axial

Ellipsoid Joint

Flattened convex surface with deep concave surface

• Ex. Radiocarpal joint

• Permits flexion/extension and abduction/adduction

• Bi-axial

Saddle Joint

Concave and convex surface oriented perpendicular to each other

• Ex. CMC of the thumb

• Bi-axial

Triaxial

only Ball & Socket

• Ex. Hips and Glenohumeral Joint

• Flexion/Extension, abduction/adduction, rotation

Spherical covex surface with a concave surface

Condyloid

Flattened convex surface with deep concave surface

Ellipsoid

Concave and convex surface oriented perpendicular to each other

Saddle

• CMC of the thumb

Synarthrodial Joints

• Skull sutures, for example

• No movement

• fibrous structure offers stability

• fit between bony segments (very tight, very congruent)

Amphiarthrodial Joints

• Intervertebral (spine) joints, for example

• Slight movement

• provides great stability and limited mobility

• fibrous and hyaline (articular) cartilage

Diarthrodial (synovial) Joints

• Shoulder, Hip, Knee, for example

• Free movement

• most common joint in body

• Stratus fibrosum (thicker)

• Stratum synovium (produces synovial fluid)

• either ovoid (egg) or sellar shaped (saddle)

Rolling joint motion

Rotary or angular motion

Sliding (gliding)

Translatory or linear motion amongst parallel surface

Spinning

rotary/angular motion where 1 point of contact remains constant

Distraction

pulling apart at joint

Compression

joints coming together

Closed-packed Position

• The joint surfaces are maximally fitted together and the surrounding tissues are tight

• maximum stability, which is useful during activities such as weight-bearing.

Open-packed position (or loose-packed)

• The joint is in a position where the capsule and ligaments are relatively relaxed, allowing more joint play.

• typically used for joint mobilizations