Metacarpophalangeal joints

From Ganfyd

Jump to: navigation, search

The metacarpophalangeal joints (MCP joints) are condyloid synovial joints that articulate between the metacarpal bones and proximal phalanges of the hand.

Contents

Structure

The joints are formed by the articulation of the heads of the metacarpal bones with the bases of the proximal phalanges. Both bones have oval articular surfaces.

A fibrous capsule encloses each metacarpophalangeal joint. The synovial membrane lines the capsule of each joint, attaching to the margins of the articular surfaces.

Movements

The metacarpophalangeal joints are capable of a number of movements:

  • Flexion
  • Extension
  • Abduction
  • Adduction
  • Circumduction.

Note that the thumb metacarpophalangeal joint is only capable of flexion and extension - adding to the evidence that the thumb metacarpal may be a modified phalanx.

Muscles acting at the joint

Flexion

Extension

Abduction

Adduction

Ligaments

  • A triangular collateral ligament strengthens the joint capsule on each side
  • Palmar ligaments are thick plates, strongly attached to the proximal phalanx but only loosely attached to the metacarpal
  • Transverse metacarpal ligaments hold the heads of the index, middle, ring and little metacarpals together.

See also

Personal tools