Biaxial joint

Biaxial Joint

A Biaxial joint is a type of synovial joint that allows for movement along two axes. This type of joint is characterized by its ability to move in two directions or planes. The two types of biaxial joints are the condyloid joint and the saddle joint.

Structure

Biaxial joints are composed of two bones that are connected by a flexible ligament. The ends of the bones are covered with a layer of cartilage that helps to reduce friction and absorb shock. The joint is surrounded by a joint capsule that contains synovial fluid, which lubricates the joint and provides nutrients to the cartilage.

Condyloid Joint

A condyloid joint (also known as an ellipsoidal joint) is a type of biaxial joint that allows for movement in two planes: flexion and extension, and abduction and adduction. Examples of condyloid joints include the wrist joint and the metacarpophalangeal joint (the joint at the base of the fingers).

Saddle Joint

A saddle joint is another type of biaxial joint that also allows for movement in two planes. However, the movement is more complex than in a condyloid joint because the bone surfaces that articulate are both concave and convex. The only example of a saddle joint in the human body is the thumb joint (the carpometacarpal joint of the thumb).

Function

Biaxial joints allow for a greater range of motion than uniaxial joints, which only allow for movement in one plane. This increased mobility allows for more complex movements and contributes to the overall flexibility and dexterity of the body.

Clinical Significance

Damage or disease affecting biaxial joints can significantly impact a person's ability to move and perform daily activities. Conditions such as osteoarthritis, rheumatoid arthritis, and gout can cause pain and inflammation in these joints, leading to decreased mobility and function.

See Also

• Uniaxial joint
• Multiaxial joint
• Synovial joint
• Joint