Hinge

Hinge is a mechanical bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. In the context of human anatomy, a hinge joint (also known as a ginglymus) is a joint between bones that allows motion in one plane only. The hinge joint is simple in overall concept, but the details of its anatomy and its physical capabilities make it a crucial component of the body's mobility.

Anatomy of a Hinge Joint

The hinge joint is so named because it functions much like the hinge of a door, allowing movement in one direction and preventing movement in the opposite direction. This type of joint includes the elbow, knee, ankle, and the interphalangeal joints between the phalanx bones of the fingers and toes.

The hinge joint is a synovial joint, meaning it is filled with synovia, a lubricating fluid that reduces friction between the bones. The ends of the bones in a hinge joint are covered with a layer of hyaline cartilage, which also helps to reduce friction and absorb shock.

Function of a Hinge Joint

The primary function of a hinge joint is to allow movement in a single plane, which is known as monaxial movement. This type of movement includes flexion (bending) and extension (straightening). In the case of the elbow, for example, the hinge joint allows the arm to bend and straighten but prevents side-to-side motion.

Disorders and Injuries

Like all joints, hinge joints can be affected by various disorders and injuries. These can include arthritis, bursitis, and sprains. Treatment for these conditions can range from rest and physical therapy to medication and surgery.

See Also

• Joint
• Synovial joint
• Arthritis
• Bursitis
• Sprain

References

Hinge Resources
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