Muscles of hand and anatomical snuff box

1. Muscles of hand
movement of thumb
palmer apponeurosis
anatomical snuff box

2. Intrinsic Hand Muscles
• Has a origins and
insertions within the hand
• Produce weak but intricate
and precise movements of
the digits (Fine motor
skills)

3. Muscles of hand
• The intrinsic muscles of the hand are located in five compartments
1. Thenar muscles in the thenar compartment: abductor pollicis
brevis, flexor pollicis brevis, and opponens pollicis.
2. Adductor pollicis in the adductor compartment.
3. Hypothenar muscles in the hypothenar compartment: abductor
digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi.
4. Short muscles of the hand, the lumbricals, in the central
compartment with the long flexor tendons and palmaris brevis.
5. The interossei in separate interosseous compartments between the
metacarpals.

5. Thenar and adductor Muscles
• Thenar (lateral aspect of palm)
• Abductor pollicis brevis
• Opponens pollicis
• Flexor pollicis brevis
• Adductor pollicis
• Move the thumb (pollex)
• This 4 muscles form the thenar eminence, lateral rounded
contour on the palm. (ball of the thumb)

7. Abductor Pollicis Brevis
• Origin
– Flexor retinaculum
– Scaphoid
– Trapezium
• Insertion
– Lateral side of proximal phalanx
of thumb
• Action
– Abduct of thumb at CMC joint.
• Median Nerve

8. Opponens Pollicis
• Origin
• Flexor retinaculum
• Trapezium
• Insertion
• Lateral side of 1st metacarpal
(thumb)
• Action
• Opposition thumb at CMC joint.
• Median nerve

9. Flexor Pollicis Brevis
• Origin
– Flexor retinaculum
– Trapezoid
– Trapezium
– Capitate
• Insertion
– Lateral side of proximal phalanx of
thumb.
• Action
– Flexion thumb at CMC and MCP joint.
• Median and ulnar nerves

10. Adductor Pollicis
• Origin
– Oblique head – Capitate and 2nd and
3rd metacarpals
– Transverse head – 3rd metacarpal
• Insertion
– Medial side of proximal phalanx of
thumb
• Action – adduct thumb at CMC and MCP
• Ulnar Nerve

11. Hypothenar Muscles
• Medial aspect of palm
• Abductor digiti minimi
• Flexor digiti minimi brevis
• Opponens digiti minimi
• Move the digiti minimi
• This 3 muscles form the hypothenar
muscles (medial rounded contour in
the palm) – ball of the little finger

13. Abductor digiti minimi
• Origin
– Tendon flexor carpi ulnaris
– Pisiform
• Insertion
– Medial side of proximal phalanx of
little fingers.
• Action
– Abduction little finger at MCP
– Assist flexion little finger at MCP
• Ulnar nerve

14. Flexor digiti minimi brevis
• Origin
– Flexor retinaculum
– Hamate
• Insertion
– Medial side of proximal phalanx
of little fingers
• Action – flexion little finger at MCP,
assist opposition little finger at CMC
• Ulnar nerve

15. Opponens Digiti Minimi
• Origin
• Flexor retinaculum
• Hamate
• Insertion
• Medial side of entire length fifth
metacarpals (little finger)
• Action
• Opposition little finger at CMC
• Ulnar nerve

16. Intermediate Muscle
• Midpalmar / intermediate (11 muscles)
• Lumbricals
• Palmar interossei
• Dorsal interossei
• Acts on all the digits
• Important muscles for movements in skilled activities (playing
piano , writing, typing, precision handling etc)

17. Lumbricals
• Consists of 4 muscles
• Origin
– Lateral and adjacent side of tendons of flexor digitorum
profundus of each fingers (2nd – 5th)
• Insertion
– Lateral side of tendon of extensor digitorum on proximal
phalanges of each fingers (2nd – 5th)
• Action
– Flexion each finger at MCP and extend each finger at IP
• Median and ulnar nerve

18. Lumbricals
Flexor Digitorum
Profundus
1st lumbricals
Insertion to tendon of
Extensor digitorum
4th lumbricals

21. Palmar interossei
• 4 muscles
• Origin
• Sides of shafts of metacarpals of all
digits (except the middle one)
• Insertion
• Side of bases of proximal
phalanges of all digits (except the
middle finger)
• Action
• Adduction each finger at MCP
assists in Flexion each finger at
MCP
• Ulnar nerves

23. Dorsal Interossei
• 4 muscles
• Origin
• Adjacent side of metacarpals
• Insertion
• Proximal phalanx of each finger
• Action
• Abduction Finger 2-4 at MCP
• Assist Flexion Finger 2-4 at MCP and
extension at IP at the same finger
• Ulnar nerve

25. PALMAR APONEUROSIS
• Also called palmar fascia
• invests the muscles of
the palm
• consists of central,
lateral, and medial
portions.
•

26. • The central triangular portion
• Occupies the middle of the palm
• Has great strength and thickness.
• Its apex is continuous with distal border of flexor retinaculum and
receives the expanded tendon of the palmaris longus.
• Its base divides below into four slips, one for each finger
• Each slip gives off superficial fibers to the skin of the palm and finger
• The deeper part of each slip subdivides into two processes, which
are inserted into the fibrous sheaths of the flexor tendon

27. • The lateral and medial peripheral portions of palmar
aponeurosis
• Are thin& fibrous
• Cover on the radial side, the muscles of the ball of the thumb
• Cover on the ulnar side the muscles of the little finger
• They are continuous with the central portion and with the fascia
on the dorsum of the hand

29. • Functions of palmar aponeurosis
•
• Provides firm attachment to overlying skin
• Helps to form the ridges in the palm which in turn help to increase
friction so that we can grasp objects firmly.
• Protects underlying structures
• Provides attachment to muscles

30. ANATOMICAL SNUFFBOX
• The anatomical snuffbox is the concavity on radial side of wrist that appears
when thumb is fully extended
• It is bounded medially by extensor pollicis longus and laterally by extensor
pollicis brevis, and abductor pollicis longus.
• floor:scaphoid ,trapzium ,end of tendons of extensor carpii radials longus and
brevis
• Radial artery running in the floor of the snuffbox,
• Cutaneous branches ofradial nerve & cephalic vein lie in the facia forming
roof.
• Bony points palpable are : radial styloid, scaphoid trapezium, base of thumb
metacarpal
•

31. DUPUYTREN'S CONTRACTURE OR
PALMAR FIBROMATOSIS
• It is a fixed flexion contracture of the hand
where the fingers bend towards the palm and
cannot be fully extended .
• It is caused by underlying contractures of the
palmar fascia.
• The ring finger and little finger are commonly
affected. The middle finger may be affected in
advanced cases, but the index finger and the
thumb are nearly always spared.
• It progresses slowly and is usually painless.
• The tissues under the skin on the palm of the
hand thicken and shorten so that the tendons
connected to the fingers cannot move freely.

32. • MALLET FINGER
• It is an injury of the extensor
digitorum tendon of the fingers
at the distal interphalangeal
joint (DIP).
• It results from hyperflexion of
the extensor digitorum tendon,
• Usually occurs when a ball
(such as a softball, basketball,
or volleyball), while being
caught, hits an outstretched
finger and jams it (by rupturing
the extensor digitorum
tendon).

33. Thank You
For Your Unbelievable
Attention!!!

34. Movement of thumb
• Movement of the thumb is important for the precise activities of the
hand. The high degree of freedom of the movements results from the
1st metacarpal being independent, with mobile
• joints at both ends. Several muscles are required to control the
freedom of thumb movements
• Extension: extensor pollicis longus,
extensor pollicis brevis,
and abductor pollicis longus.
• Flexion: flexor pollicis longus
and flexor pollicis brevis.

35. • Abduction: abductor pollicis longus and abductor pollicis brevis.
• Adduction: adductor pollicis and 1st dorsal interosseous.
• Opposition: opponens pollicis. This movement occurs at the
carpometacarpal joint and results in a “cupping” of the palm. Bringing
the tip of the thumb into contact with the 5th finger, or any of the
other fingers, involves considerably more movement than can be
produced by the opponens pollicis alone.