Intrinsic muscles of the hand thenar hypo thenar lumbricals palmar and dorsal interossei median nerve ulnar nerve

1. Hand
(INTRINSIC MUSCLES OF HAND)
Dr. Amaan

2. INTRINSIC MUSCLES OF HAND
Features
Serve the function of:
• Adjusting the hand during gripping and
• Carrying out fine skilled movements.
• The origin and insertion of these muscles is within the territory of
the hand.

3. INTRINSIC MUSCLES OF HAND
Situated totally within the hand:
 Divided into 4 groups:-
1. Thenar
2. Hypothenar
3. Lumbricals
4. Interossei muscles
 There are 20 muscles in the hand

4. The planes of movements of the fingers

6. 1. a. Three muscles of thenar eminence
i. Abductor pollicis brevis
ii. Flexor pollicis brevis
iii. Opponens pollicis
• b. One adductor of thumb: Adductor pollicis

7. Thenar Muscles
a. Abductor pollicis brevis
b. Flexor pollicis brevis
c. Opponens pollicis
d. Adductor pollicis

8. 1. ABDUCTOR POLLICIS BREVIS
Origin: flexor retinaculam,
Scaphoid &Trapezium
Insertion:
Lateral side of base of proximal
phalanx of thumb
Action:
Abducts thumb
Innervation
median nerve

9. 2. FLEXOR POLLICIS BREVIS
Origin: flexor retinaculam,
Trapezium, capitate
Insertion:
Lateral side of base of proximal
phalanx of thumb
Action:
Flexes thumb
Innervation
median nerve

10. 3. OPPONENS POLLICIS
Origin: flexor retinaculam,
Trapezium
Insertion:
Lateral side of 1st metacarpal
Action:
pulls thumb medially &forward
across the palm (opposes
thumb towards the fingers)
Innervation
median nerve

11. 4. ADDUCTOR POLLICIS
Origin:
oblique head:-
2nd,3rd metacarpals
transverse head:
3rd metacarpal
Insertion:
medial side of base of proximal
phalanx of thumb
Action:
Adducts thumb
Innervation
ulnar nerve

12. 2. Four hypothenar muscles
i. Palmaris brevis.
ii. Abductor digiti minimi.
iii. Flexor digiti minimi.
iv. Opponens digiti minimi.
Muscles (ii) to (iv) are muscles of hypothenar eminence.

13. 2. Hypothenar Muscles

14. 1. PALMAR BREVIS
Origin: flexor
retinaculam,
Insertion:
Skin on the medial
side of the palm
Action:
Wrinkles the skin
on the medial side
of the palm
Innervation
superficial branch of
ulnar nerve

15. 2. ABDUCTOR DIGITI MINIMI
The most superficial of the
hypothenar muscles forming
the hypothenar eminence
Origin: Pisiform bone
Insertion:
proximal phalanx of 5th digit
(little finger)
Action:
abducts little finger
Innervation
deep branch of ulnar nerve

16. 3. FLEXOR DIGITI MINIMI
Origin: Hook of
hamate and flexor
retinaculum
Insertion:
proximal phalanx of 5th
digit (little finger)
Action:
flexes little finger
Innervation
deep branch of ulnar nerve

17. 4. OPPONENS DIGITI MINIMI
Origin: flexor
retinaculum
Insertion:
Medial border of 5th
metacarpal
Action:
Brings little finger (5th
digit) into opposition
with thumb
Innervation
deep branch of ulnar nerve

18. 3. Four lumbricals.
4. Four palmar interossei.
5. Four dorsal interossei.

19. 3. LUMBRICAL MUSCLES (four)
They are named as such
because of their elongated
wormlike form
1. Lumbricals 1 and 2
Origin: lateral 2 tendons of flexor
digitorum profundus
2. Lumbricals 3 and 4
Origin: medial 3 tendons of flexor
digitorum profundus
Insertion: lateral sides of extensor
expansions of digits 2 to 5
Action: To flex digits at MCP joints
and extend IP joints

22. (a) The dorsal interossei muscles, and (b) palmar interossei
muscles

25. The origin of the lumbrical muscles from tendons of flexor digitorum
profundus (Layer 2 of palm)

27. (a) The dorsal interossei muscles, and (b) palmar interossei
muscles

28. Test for palmar
interossei
Testing adductor pollicis

29. Thenar, midpalmar, dorsal subcutaneous and dorsal
subaponeurotic spaces. I, II, III, IV—dorsal interossei and 1, 2, 3,

30. Thank you