muscles of hand

1. Hand

2. Hand
• Composed of
• Bones
• Muscles
• Ligaments
• To allow a large amount of
movements

3. Hand
• Has 2 surfaces
• Palmar
• Dorsal

4. Palm – Features
• Hollow
• Eminence
• Creases

5. Palm – Features
• Palmar surface
• Thick skin
• Devoid of
• Hairs & sebaceous glands
• Connected with deep fascia by
• Many fibrous septa
• Helps grip by restricting mobility of skin
• Has fat
• Act as cushion
• To withstand pressure

6. Palm - features
• Has
• Creases or lines
• 3 types
• Flexure lines
• Papillary ridges
• Langer lines

7. Creases - Flexure lines
• Visible marking
• Lies close to joints
• On medial 4 fingers
• 2 interphalangeal creases
• Proximal crease only marks joint
• Crease between palm & fingers
• Do not represent the metacarpo-
phalangeal joint
• Joint lies 2 cm proximal to crease
• Distal skin crease of wrist
• Represents proximal border of flexor
retinaculum
• At the midpoint
• Median nerve passes behind

8. Creases - Flexure lines
• Wrist
• Proximal
• Distal
• Palm
• Longitudinal
• Mid-palmar
• Radial
• Transverse
• Proximal
• Longitudinal
• Applied anatomy – Simian’s crease
• Phalanges
• Proximal
• Middle
• Distal

9. Creases – Papillary ridges
• Otherwise - Finger prints
• Peculiar over the flexor surface of
distal phalanges
• Corresponds to
• Pattern of underlying dermal papilla
• Ducts of sweat gland opens
• 3 types
• Whorl, loop & arch
• Helps in personal identity
• Dermatoglyphics
• Science of finger prints

10. Creases – Langer lines
• Produced by
• Bundles of collagen fibres of dermis
• On dorsum
• Transverse
• On palm
• Longitudinal

11. Hand - Dorsum
• Dorsal surface
• Thin skin
• Presence of
• Hair & sebaceous & sweat glands
• Beneath skin
• Dorsal digital nerves
• Dorsal venous plexus
• Drains not only
• Dorsal surface but also palm
• To avoid the pressure of grip

12. Superficial fascia
• Subcutaneous tissue
• Contains
• Fat
• Palmaris brevis
• Lies across the base of hypothenar
eminence
• Superficial transverse ligament of palm
• Across roots of medial 4 fingers

13. Palmaris brevis
• Lies across the base of hypothenar eminence
• Origin
• Flexor retinaculum & central part of palmar
aponeurosis
• Insertion
• Dermis of ulnar border of hand
• Nerve supply
• Superficial branch of ulnar nerve
• Action
• Improves the grip
• Morphology
• Remnant of Panniculus carnosus
•

14. Superficial transverse ligament of Palm
• Modification of superficial fascia
• Stretches across
• Free margin of the webs of medial four
fingers
• Structures passing deep to it
• Digital vessels & nerves

15. Cutaneous nerves
• Palmar cutaneous branch of
median– in lower part of
forearm – passes into hand
above flexor retinaculum –
supplying skin over thenar
eminence & middle of palm
• Palmar cutaneous of ulnar –
near lower forearm –supplies
skin of medial 1/3 of palm

16. Deep fascia
• Thickened at 3 sites
• Flexor retinaculum
• Palmar aponeurosis
• Fibrous flexor sheath

17. Palmar aponeurosis
• Triangular in shape
• Occupies the central area of the palm
• Has
• Apex
• Base
• Apex
• Blends with distal border of flexor
retinaculum
• Continuous with palmaris longus tendon
• Base
• Lies at bases of medial four fingers
• Divides into four digital slips
• Further each digital slip divided into
• Superficial & deep sets of fibres

18. Palmar aponeurosis – superficial & deep fibres
• Superficial fibres
• Joins with dermis
• Blend with superficial
transverse ligament of palm
• Deep fibres
• Divides into 2 bands
• Attaches to
• Deep transverse ligament of
palm
• Palmar ligament of
metacarpophalangeal joint
• Bases of proximal phalanges
• Fibrous flexor sheaths

19. Palmar aponeurosis – space between the slips
• Intervals between the four digital
slips
• Connected by transverse fibres
• Structures passing
• Digital vessels
• Digital nerves
• Lumbricals

20. Palmar aponeurosis – medial & lateral palmar septa
• Medial septum
• From medial margin
• To palmar surface of shaft of 5th
metacarpal
• Lateral septum
• From lateral margin
• To 1st metacarpal bone
• Septa subdivide the palm into
fascial spaces

21. Palmar aponeurosis – functions
• Powerful grip
• By firm attachment of overlying skin
• Prevents bow-stringing
• Of flexor tendons
• Protects
• Vessels & nerves
• Provides
• Origin to palmaris brevis
• Potential spaces
• Septa from aponeurosis forms
• Peculiarity from plantar aponeurosis
• Absence of digital slip to thumb
• Allows free movement of thumb
• Plantar aponeurosis
• Has 5 slips
• Morphology
• Degenerated part of palmaris longus tendon

22. Palmar aponeurosis
• Thickened deep fascia of the hand
• Triangular in shape
• Occupies the central area of the palm
• The apex is attached to the distal border
of flexor retinaculum and receives the
insertion of palmaris longus tendon.
• Base divides at the bases of the fingers
into four slips that pass into the fingers
• Functions
• Gives firm attachment to the overlying skin
and improves the grip.
• Protects the underlying tendons, vessels &
nerves

23. Palmar aponeurosis (Central part)
• Thickened deep fascia of the hand
• Triangular in shape
• Occupies the central area of the palm
• Apex is attached to the distal border of
flexor retinaculum and receives the
insertion of palmaris longus tendon.
• Base divides at the bases of the fingers
into four slips that pass into the fingers
• Functions:
• Gives firm attachment to the overlying skin
and improves the grip.
• Protects the underlying tendons, vessels &
nerves

24. Dupuytren’s contracture
• Hypertrophy of palmar
aponeurosis –progressive
fibrosis (ulnar side)
• Shortening & thickening of
fibrous bands from aponeurosis
to little and ring fingers

25. Intrinsic muscles of hand

26. Intrinsic muscles
• Thenar
• Hypothenar
• Lumbricals
• Interossei muscles

27. Intrinsic Muscles
• Situated totally within the hand
• Divided into 4 groups:-
• Lateral group
• Four thenar muscles
• Medial group
• Three hypothenar muscles
• Palmaris brevis
• Central group:
• Four lumbricals
• Four palmar interossei
• Four dorsal interossei
• All muscles are supplied by
• C 8 & T 1 spinal segments
• Through median & ulnar nerves

28. Lumbricals
• Earth worm
• 4 lumbricals
• Numbered from lateral to medial
• Arise from 4 tendons of FDP
• Inserted into extensor expansion
• Numbered from lateral to medial
• First & second are
• Unipennate
• Supplied by Median nerve
• Third & fourth are
• Bipennate
• Supplied by deep branch of ulnar
• Left Hand

29. Lumbricals - origin
• I lumbrical
• From radial side of tendon for index
finger
• II lumbrical
• From radial side of tendon of middle
finger
• III lumbrical
• From adjacent sides of the tendons for
middle & ring fingers
• IV lumbrical
• From adjacent sides of the tendons for
ring & little fingers
• Right Hand

30. Lumbricals
• Insertion
• All lumbricals pass backwards on radial side
of
• 2nd , 3rd , 4th & 5th metacarpo-phalangeal joints
respectively
• Insert on lateral angle of extensor expansion
• Action
• Flex the metacarpo-phalangeal joints
• Extend the interphalangeal joints

31. Thenar muscles
• Abductor pollicis brevis
• Flexor pollicis brevis
• Opponens pollicis
• Adductor pollicis

32. Abductor pollicis brevis
• Origin
• Tubercle of Scaphoid
• Crest of Trapezium
• Flexor retinaculum
• Insertion
• Lateral aspect of proximal phalanx of
thumb
• Near base
• Action
• Abduction & medial rotation
• At
• Metacarpophalangeal joint
• Carpometacarpal joint
• Right angle to the thumb
• Nerve supply
• Recurrent branch of Median (C 8 &
T1)

33. Flexor pollicis brevis
• Origin
• Superficial head
• Crest of Trapezium
• Flexor retinaculum
• Deep head
• Trapezoid
• Capitate
• Insertion
• Lateral aspect of proximal phalanx of
thumb
• Near base
• Action
• Flexion of carpometacarpal &
metacarpophalangeal joints
• Nerve supply
• Recurrent branch of Median (C 8 & T1)

34. Opponens pollicis
• Origin
• Tubercle of trapezium
• Flexor retinaculum
• Insertion
• I metacarpal
• Lateral margin & lateral
palmar aspect
• Action
• Opposition
• At carpo metacarpal joint
• Rotating & flexing the
metacarpal on trapezium

35. Thenar eminence
• Raised region between wrist & base of
thumb
• Muscles
• Abductor pollicis brevis(median)
• Opponens pollicis(median)
• Flexor pollicis brevis(median & ulnar)
• Adductor pollicis(ulnar)
Carpal tunnel syndrome

36. Adductor pollicis
• Origin
• Oblique head – capitate, trapezoid &
bases of 2nd & 3rd metacarpal bones
• Transverse head – distal 2/3rd of shaft
of 3rd metacarpal bone
• Insertion
• Ulnar side of base of proximal phalanx
of thumb
• Action
• Transverse head – adductor &flexor of
thumb
• Nerve supply – Ulnar nerve (deep)
C8 &T1

37. Interossei
• Deepest structure of hand
• Between the metacarpal bones
• 8 muscles present
• Arranged in 2 groups
• Palmar interossei (4)
• Dorsal interossei (4)

38. Palmar interossei
• Superficial than dorsal interossei
• Smaller ones
• Unipennate
• Adduct the fingers towards middle finger
• No adductors for middle finger
• Origin
• 1st & 2nd
• Medial side of shafts of 1st & 2nd metacarpals
• 3rd & 4th
• From radial side of shafts of 4th & 5th metacarpals
• Insertion
• Base of proximal phalanx of corresponding digit on
side of their origin
• Dorsal digital expansion
2
3
4

39. Dorsal interossei
• Deepest structure
• Fill up intermetacarpal spaces
• Bipennate
• Abductors
• Little & thumb have their own
abductors
• Middle finger require abduction on
both sides

40. Dorsal interossei
• Fills up all (4) intermetacarpal spaces
• Origin
• Contiguous sides of shafts of
metacarpals
• Leaves a gap in between their origin
• Space between first dorsal interossei
transmits
• Radial artery
• Gap between 2nd 3rd & 4th dorsal
interossei transmits
• Proximal perforating arteries

41. Dorsal interossei
• Insertion
• Proximal phalanges of 2nd, 3rd & 4th
• Middle finger gets insertion on both
sides
• 1st & 2nd
• Radial side of bases of proximal
phalanges of index & middle
• 3rd & 4th
• Ulnar side of bases of proximal
phalanges of middle & ring fingers
• Nerve supply
• Deep branch of ulnar

42. • Lateral & medial angles of dorsal digital expansion of
• Index, middle & ring fingers receives
• Interossei

43. Hypothenar muscles
• Abductor digiti minimi
• Flexor digiti minimi
• Opponens digiti minimi

44. Abductor digiti minimi
• Origin
• Pisiform, tendon of flexor carpi ulnaris
• Insertion
• Ulnar side of base of proximal phalanx
• Action
• Abductor of little finger
• Nerve supply
• Ulnar (deep) C8 & T1

45. Flexor digiti minimi brevis
• Origin
• Hook of hamate
• Flexor retinaculum
• Insertion
• Ulnar side of base of proximal phalanx
of little finger
• Action
• Flexor of proximal phalanx of little
finger
• Nerve supply
• Ulnar (deep) C8 & T1

46. Opponens digiti minimi
• Origin
• Hook of hamate
• Flexor retinaculum
• Insertion
• Ulnar border of 5th metacarpal
• Action
• Flexes 5th metacarpal
• Nerve supply
• Ulnar (deep) C8 & T1

47. Deep branch of ulnar nerve
• Course
• Passes between abductor digiti
minimi & flexor digiti minimi
• Accompanied by deep branch of ulnar
artery
• Perforates opponens digiti minimi
• Follow deep palmar arch

48. Branches
• Muscular
• Abductor digiti minimi
• Flexor digiti minimi brevis
• Opponens digiti minimi
• 3rd & 4th lumbricals
• Adductor pollicis
• Flexor pollicis brevis
• Interossei
• Articular
• Intercarpal, carpometacarpal joints
• Blood vessels – ulnar & palmar arteries

49. Median nerve contd…
• Muscular branches to Thenar muscles
– Abductor pollicis brevis
– Flexor pollicis brevis
– Opponens pollicis
• Branches from digital nerves supply
– 1st & 2nd lumbricals