The Hand

carpometacarpal dorsal interossei hand hypothenar eminence intermetacarpal joints interphalangeal joints lumbricals metacarpophalangeal joints palmar interossei thenar eminence

anatomy of the hand Physiotherapy Solihull Simon Evans

The Hand

  • Anatomically comparable to the foot
    • Bones divided into structural and functional divisions
    • Muscles controlling can be found extrinsically and intrinsically
    • Foot adapted for weight bearing, hand adapted for prehension

Joints of the Hand - Carpometacarpal & Intermetacarpal Joints

  • Carpometacarpal and intermetacarpal joints are a series of synovial plane joints (except 1st) 
  • Articular surfaces are covered in hyaline cartilage and surrounded by a capsule and synovial membrane - reinforced by palmar, dorsal and interosseous ligaments
  • Functionally important to allow gliding during hand and wrist movements

1st Carpometacarpal Joint

  • Syonivial saddle joint (typical synovial joint)
  • Reinforced by radial collateral (trapezium to MC),  anterior oblique (covers joint obliquely anteriorly) and posterior oblique (covers posterior joint obliquely) ligaments
  • Functionally oblique ligaments produce a conjunct rotation of the MCP joint

Metacarpophalangeal (MCP) Joints

  • Synovial condyloid joints between rounded head of metacarpals and concave bases of proximal phalanges
  • Typical synovial joints - note extended area for articulation on the anterior aspect of metacarpal heads
  • Ligaments pass from lateral tubercles to palmar aspect of proximal phalanx - taut in flexion and therefore limit abd/adduction in this position
  • Note also volar (plate) and transverse ligaments

Interphalangeal (IP) Joints

  • Proximal (PIP) and distal (DIP) joints - uniaxial synovial hinge joints
  • Between distal rounded ends of phalanges with proximal concave ends of adjacent phalanx
  • Typical synovial joints reinforced by strong collateral ligaments 

Intrinsic muscles of the hand

  • Muscles which have proximal and distal attachments within the anatomical boundaries of the hand
  • Anatomically distinct areas
    • Thenar eminence
    • Hypothenar eminence
    • Interossei/lumbricals

Thenar Eminence

  • Include
  • Superficial
    • Flexor pollicis brevis
    • Abductor pollicis brevis
  • Deep
    • Adductor pollicis - 2 heads (transverse and oblique)
    • Opponens pollicis
  • NS: Median nerve except adductor pollicis that is supplied by the ulnar nerve (C8,T1) 

Hypothenar Eminence

  • Also divided into deep and superficial muscles
  • Superficial
    • Flexor digiti minimi
    • Abductor digiti minimi
  • Deep
    • Opponens digiti minimi
  • NS: Ulnar nerve C8,T1

Palmar Interossei

  • Between adjacent metacarpals - unipennate
  • Attach to the bases of proximal phalanges (medial 2 to 4th 5th digits, lateral 1 to 2nd digit)
  • Adductors of the MCP joints of index, ring and little fingers
  • NS: Ulnar nerve C8,T1

Dorsal Interossei

  • Bipennate - from adjacent metacarpals
  • To bases of proximal phalanges - 1st and 2nd to lateral side of index and middle, 3rd and 4th to medial side of middle and ring fingers 
  • Abduction of MCP of index, middle and ring fingers
  • NS: Ulnar nerve C8,T1

Lumbricals

  • 4 muscle attaching the long flexor tendons (FDP) with the dorsal digital expansion of ED - 1st pair unipennate and 2nd pair bipennate
  • A: flexion of MCP and extension of IP joints
  • NS: medial pair via ulnar nerve, lateral pair via median nerve (C8,T1)

See More Articles on the Human Anatomy - Click Hereanatomy of the hand Physiotherapy Solihull Simon Evans



Older Post Newer Post