Muscles of the upper limb

Muscles of the forearm

Flexor

• Superficial compartment
  • Flexor Carpi Radialis
  • Flexor Carpi Ulnaris
  • Palmaris Longus
  • Pronator Teres
• Intermediate compartment
  • Flexor Digitorum Superficialis
• Deep compartment
  • Flexor Digitorum Profundus
  • Flexor Pollicis Longus
  • Pronator Quadratus

Superficial compartment

• All originate from a common tendon, which arises from the medial epicondyle of the humerus

• All supplied by Median Nerve apart from Flexor Carpi Ulnaris which is supplied by Ulnar Nerve

• Flexor Carpi Radialis

• Flexor Carpi Ulnaris

• Palmaris Longus

• Pronator Teres

Intermediate compartment

• Flexor Digitorum Superficialis
• Median and ulnar nerve pass between its two heads
• Innervated by the median nerve
• Actions: Flexes the metacarpophalangeal joints and proximal interphalangeal joints at the 4 fingers, and flexes at the wrist.

Deep compartment

• Flexor Digitorum Profundus
  • Origin
    • Ulnar and interosseous membrane
  • Action
    • Flex distal interphalangeal jionts
  • Inervation
    • Medial half - Ulnar nerve
    • Lateral half - Median nerve
• Flexor Pollicis Longus
• Pronator Quadratus

Muscles of the hand

• Extrinsic - in the forearm but produce action in the hand
• Intrinsic - located in the hand, responsible for fine motor function

Thenar muscles

• Supplied by Median Nerve
• Opponens pollicis
• Abductor pollicis brevis
• Flexor pollicis brevis

Hypothenar muscles

• Supplied by the Ulnar Nerve
• Opponens digiti minimi
• Abductor digiti minimi
• Flexor digiti minimi brevis

Lumbricals

• Innervation
  • Lateral two - median nerve
  • Median two - ulnar nerve

Interossei

• Dorsal interossei
  • Ulnar nerve
• Palmer interossei
  • Ulnar nerve

Other muscles in the palm

• Palmaris brevis
• Adductor pollicis

Palmar aponeurosis