W11 L8
Lecture 8 - Intrinsic muscles & structures of the
hand and the neuromusculoskeletal movement
of the superior appendicular skeleton
CHI108 W11 L8 flashcards
Learning objectives
1. Review the palmar and dorsal, extrinsic and intrinsic muscular attachments.
2. Review and determine the palmar aponeurosis and the arrangement of the specialised
reinforcing ligamentous structures of the hand.
3. Determine and investigate the palmar and dorsal intrinsic muscles of the hand.
4. Determine and investigate the intrinsic muscles of the hand.
5. Begin to develop an initial understanding of how various muscles generate the unique
movements observed within the joints of the hands.
6. Describe the motion and muscle functions of primary joints of the upper appendicular skeleton.
__________________________________________________________________________________
Bones of the wrist and hand - extrinsic attachments
Palmar surface
Palmar and dorsal surfaces of the hand and
extensor tendons
• 1: Proximal, middle and distal phalanges
• 2: Metacarpals
Distal row
• 3: Hamate
• 7: Capitate
• 9: Trapezoid
• 10: Trapezium
Proximal row
• 8: Scaphoid
• 6: Lunate
• 4: Triquetral
• 5: Pisiform Palmar and dorsal - extrinsic and intrinsic
muscular attachments
Dorsal surface
• 1: Proximal, middle and distal phalanges
• 2: Metacarpals
Distal row
• 3: Hamate
• 6: Capitate
• 8: Trapezoid
• 9: trapezium
Proximal row
• 7: Scaphoid
• 5: Lunate
• 4:Triquetral, pisiform not visible dorsally
Extensor tendons
• 1: Extensor pollicis longus
• 2: Extensor pollicis brevis
• 3: Abductor pollicis longus
• 4: Extensor carpi radialis longus and brevis
• 5: Extensor carpi ulnaris
• 6: Extensor digiti minimi Palmar aponeurosis
• 7: Extensor indicis
• 8: Tendons of extensor digitorum
Palmar and dorsal - extrinsic and intrinsic muscular attachments
• Thenar muscles (median n.)
○ Flexor pollicis brevis (NB: deep part - ulnar n.)
○ Abductor pollicis brevis
○ Opponens pollicis
• Hypothenar muscles (ulnar n.)
○ Flexor digiti minimi
○ Abductor digiti minimi
○ Opponens digiti minimi
CHI108 Page 1
, ○ Opponens pollicis
• Hypothenar muscles (ulnar n.)
○ Flexor digiti minimi
○ Abductor digiti minimi
○ Opponens digiti minimi
• Adductor pollicis (ulnar n.) (transverse and oblique heads)
• Palmar interossei (3) (ulnar n. ("PAD"))
• Dorsal interossei (4) ("DAB"))
• Lumbricals (4)
Palmar aponeurosis
• The muscular fascia of the palm is thickened by firm connective tissue to form the palmar
aponeurosis
• The palmar aponeurosis separates the palm from the subcutaneous fat and protect the deeper
soft tissues
• It is composed mainly of longitudinal fibre bundles which give it a fan-shaped arrangement
• The longitudinal fascicles are held together by transverse (fascicles) fibre bundles superficially to
the metacarpal bones
• At the level of the metacarpophalangeal joints the longitudinal (fascicles) are held together by the
superficial transverse metacarpal ligament.
• The palmaris longus and the smaller palmaris brevis keep the palmar aponeurosis tense
Palmar carpal and digital tendon sheaths
Palmar carpal and digital tendon sheaths
• The palmar aponeurosis has been removed
• The tendons of the flexor pollicis longus, flexor digitorum superficialis, and flexor digitorum
profundus run from the distal forearm through a fibro-osseous canal (carpal tunnel) to the palm,
accompanied by the median nerve
• These structures are in the carpal tunnel are protected by the palmar carpal tendon sheaths
• The carpal tendon sheath of the flexor pollicis longus is consistently continuous with the digital
tendon sheath of the thumb
• The digital tendon sheaths of the remaining fingers show variable communication with the carpal
tendon sheaths
Superficial layer of the muscles
• The antebrachial (forearm) fascia, palmar aponeurosis and palmaris brevis and longus
muscles, palmar carpal and digital tendon sheaths tendon sheaths have been removed
• Removed is the fibrous digital sheath which encloses all digits
• Once the fibrous digital sheath is removed the annular (5) and cruciate (3) (pulleys) ligaments are
seen supporting the digital tendon sheaths and enclosed tendons, digits 2 to 5
• Known as the “flexor pulley system”, the pollex displays oblique and annular (pulleys) ligaments
• Thenar muscles (median n.)
○ Flexor pollicis brevis (superficial head) (NB: deep part= Ulnar n)
○ Abductor pollicis brevis
○ Opponens pollicis
• Adductor pollicis: (ulnar n.) Superficial layer of the muscles
○ Transverse head
○ Oblique head
• Lumbricals (4) (median and ulnar)
• Hypothenar muscles (ulnar n.)
○ Flexor digiti minimi brevis
○ Abductor digiti minimi
○ Opponens digiti minim
Intermediate layer of the muscles
• The flexor digitorum superficialis muscle has been removed, and the four tendons have been
sectioned at the level of the metacarpophalangeal joints
• The first to third annular ligaments have been cut open to reveal flexor tendons of the fingers
• The flexor retinaculum has been partially removed to open the carpal tunnel
• Of the thenar muscles, portions of the abductor pollicis brevis and flexor pollicis brevis (superficial
head) have been removed
• Part of the abductor digiti minimi has been resected on the hypothenar side
• Lumbricals: flexion of MCPJ and extension of DIP/PIP 2-5
○ 1st and 2nd proximal attachment is the lateral two tendons of the flexor digitorum
profundus as unipennate muscles
○ 3rd and 4th proximal attachment is the medial three tendons of the flexor digitorum
profundus as bipennate muscles
○ “1 2 me, 3 4 u” median and ulnar nerve
Intermediate layer of the muscles
Intermediate to deep layers of the muscles
• The flexor digitorum profundus muscle has been removed, and the four tendons have been
sectioned at the level of the proximal aspect of the metacarpophalangeal joints
• The lumbricals arising from them have been sectioned at the same level as the flexor digitorum
profundus
• The flexor pollicis longus and flexor digiti minimi muscles have also been removed
• Adductor pollicis
○ Transverse head
○ Oblique head
• Palmar interossei (3)
• Dorsal interossei (4)
○ “PAD” & “DAB”
○ Ulnar nerve
CHI108 Page 2
Lecture 8 - Intrinsic muscles & structures of the
hand and the neuromusculoskeletal movement
of the superior appendicular skeleton
CHI108 W11 L8 flashcards
Learning objectives
1. Review the palmar and dorsal, extrinsic and intrinsic muscular attachments.
2. Review and determine the palmar aponeurosis and the arrangement of the specialised
reinforcing ligamentous structures of the hand.
3. Determine and investigate the palmar and dorsal intrinsic muscles of the hand.
4. Determine and investigate the intrinsic muscles of the hand.
5. Begin to develop an initial understanding of how various muscles generate the unique
movements observed within the joints of the hands.
6. Describe the motion and muscle functions of primary joints of the upper appendicular skeleton.
__________________________________________________________________________________
Bones of the wrist and hand - extrinsic attachments
Palmar surface
Palmar and dorsal surfaces of the hand and
extensor tendons
• 1: Proximal, middle and distal phalanges
• 2: Metacarpals
Distal row
• 3: Hamate
• 7: Capitate
• 9: Trapezoid
• 10: Trapezium
Proximal row
• 8: Scaphoid
• 6: Lunate
• 4: Triquetral
• 5: Pisiform Palmar and dorsal - extrinsic and intrinsic
muscular attachments
Dorsal surface
• 1: Proximal, middle and distal phalanges
• 2: Metacarpals
Distal row
• 3: Hamate
• 6: Capitate
• 8: Trapezoid
• 9: trapezium
Proximal row
• 7: Scaphoid
• 5: Lunate
• 4:Triquetral, pisiform not visible dorsally
Extensor tendons
• 1: Extensor pollicis longus
• 2: Extensor pollicis brevis
• 3: Abductor pollicis longus
• 4: Extensor carpi radialis longus and brevis
• 5: Extensor carpi ulnaris
• 6: Extensor digiti minimi Palmar aponeurosis
• 7: Extensor indicis
• 8: Tendons of extensor digitorum
Palmar and dorsal - extrinsic and intrinsic muscular attachments
• Thenar muscles (median n.)
○ Flexor pollicis brevis (NB: deep part - ulnar n.)
○ Abductor pollicis brevis
○ Opponens pollicis
• Hypothenar muscles (ulnar n.)
○ Flexor digiti minimi
○ Abductor digiti minimi
○ Opponens digiti minimi
CHI108 Page 1
, ○ Opponens pollicis
• Hypothenar muscles (ulnar n.)
○ Flexor digiti minimi
○ Abductor digiti minimi
○ Opponens digiti minimi
• Adductor pollicis (ulnar n.) (transverse and oblique heads)
• Palmar interossei (3) (ulnar n. ("PAD"))
• Dorsal interossei (4) ("DAB"))
• Lumbricals (4)
Palmar aponeurosis
• The muscular fascia of the palm is thickened by firm connective tissue to form the palmar
aponeurosis
• The palmar aponeurosis separates the palm from the subcutaneous fat and protect the deeper
soft tissues
• It is composed mainly of longitudinal fibre bundles which give it a fan-shaped arrangement
• The longitudinal fascicles are held together by transverse (fascicles) fibre bundles superficially to
the metacarpal bones
• At the level of the metacarpophalangeal joints the longitudinal (fascicles) are held together by the
superficial transverse metacarpal ligament.
• The palmaris longus and the smaller palmaris brevis keep the palmar aponeurosis tense
Palmar carpal and digital tendon sheaths
Palmar carpal and digital tendon sheaths
• The palmar aponeurosis has been removed
• The tendons of the flexor pollicis longus, flexor digitorum superficialis, and flexor digitorum
profundus run from the distal forearm through a fibro-osseous canal (carpal tunnel) to the palm,
accompanied by the median nerve
• These structures are in the carpal tunnel are protected by the palmar carpal tendon sheaths
• The carpal tendon sheath of the flexor pollicis longus is consistently continuous with the digital
tendon sheath of the thumb
• The digital tendon sheaths of the remaining fingers show variable communication with the carpal
tendon sheaths
Superficial layer of the muscles
• The antebrachial (forearm) fascia, palmar aponeurosis and palmaris brevis and longus
muscles, palmar carpal and digital tendon sheaths tendon sheaths have been removed
• Removed is the fibrous digital sheath which encloses all digits
• Once the fibrous digital sheath is removed the annular (5) and cruciate (3) (pulleys) ligaments are
seen supporting the digital tendon sheaths and enclosed tendons, digits 2 to 5
• Known as the “flexor pulley system”, the pollex displays oblique and annular (pulleys) ligaments
• Thenar muscles (median n.)
○ Flexor pollicis brevis (superficial head) (NB: deep part= Ulnar n)
○ Abductor pollicis brevis
○ Opponens pollicis
• Adductor pollicis: (ulnar n.) Superficial layer of the muscles
○ Transverse head
○ Oblique head
• Lumbricals (4) (median and ulnar)
• Hypothenar muscles (ulnar n.)
○ Flexor digiti minimi brevis
○ Abductor digiti minimi
○ Opponens digiti minim
Intermediate layer of the muscles
• The flexor digitorum superficialis muscle has been removed, and the four tendons have been
sectioned at the level of the metacarpophalangeal joints
• The first to third annular ligaments have been cut open to reveal flexor tendons of the fingers
• The flexor retinaculum has been partially removed to open the carpal tunnel
• Of the thenar muscles, portions of the abductor pollicis brevis and flexor pollicis brevis (superficial
head) have been removed
• Part of the abductor digiti minimi has been resected on the hypothenar side
• Lumbricals: flexion of MCPJ and extension of DIP/PIP 2-5
○ 1st and 2nd proximal attachment is the lateral two tendons of the flexor digitorum
profundus as unipennate muscles
○ 3rd and 4th proximal attachment is the medial three tendons of the flexor digitorum
profundus as bipennate muscles
○ “1 2 me, 3 4 u” median and ulnar nerve
Intermediate layer of the muscles
Intermediate to deep layers of the muscles
• The flexor digitorum profundus muscle has been removed, and the four tendons have been
sectioned at the level of the proximal aspect of the metacarpophalangeal joints
• The lumbricals arising from them have been sectioned at the same level as the flexor digitorum
profundus
• The flexor pollicis longus and flexor digiti minimi muscles have also been removed
• Adductor pollicis
○ Transverse head
○ Oblique head
• Palmar interossei (3)
• Dorsal interossei (4)
○ “PAD” & “DAB”
○ Ulnar nerve
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