Download MUSCLES OF HAND MOVEMENTS OF THUMB PALMAR

MUSCLES OF HAND
MOVEMENTS OF THUMB
PALMAR APONEUROSIS
ANATOMICAL SNUFFBOX
LEARNING OBJECTIVES
At the end of lecture student should be able to:
•Recall the structure and functions of palmar aponeurosis
•Recall the attachments, nerve supply & actions of muscles of hand
•Correlate the movements of thumb with hand anatomy
• Identify the anatomical snuffbox
•Relate applied with gross anatomy of few structures of hand
Deep fascia of wrist is thickened to form flexor retinaculum and palmar
aponeurosis
•
•
•
PALMAR APONEUROSIS
Also called palmar fascia
Invests the muscles of the palm
Consists of central, lateral, and medial portions.



THE CENTRAL TRIANGULAR PORTION
Occupies the middle of the palm
Has great strength and thickness
Apex is continuous with the distal border of flexor retinaculum and
receives the expanded tendon of the palmaris longus



•
•
•
•
•
•
•
•
THE CENTRAL TRIANGULAR PORTION
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 tendons
THE LATERAL AND MEDIAL PERIPHERAL PORTIONS OF PALMAR
APONEUROSIS
Are thin& fibrous
Cover on the radial side by the muscles of the ball of the thumb
Cover on the ulnar side by the muscles of the little finger
Continuous with the central portion and with the fascia on the dorsum
of the hand
FUNCTIONS OF PALMAR APONEUROSIS
Provides firm attachment to overlying skin
Helps to form the ridges in the palm which helps to grasp objects firmly
Protects underlying structures
Provides attachment to muscles
DEEP MUSCLES OF PALM
After removing skin palmar aponeurosis and flexor
retinaculum structures seen are:
 The tendons of the flexor digitorum superficialis
Medial to the tendons a group of muscles acting on
the little finger, the hypothenar muscles
Lateral to the tendons a group of muscles acting on
the thumb (pollux), the thenar muscles
THENAR & HYPOTHENAR MUSCLES


•
•
•

•
THENAR MUSCLES
Comprise the intrinsic musculature of the thumb
Include the
Abductor pollicis brevis
Flexor pollicis brevis
Opponens pollicis
Other than thenar muscles thumb also has
Adductor pollicis
THENAR MUSCLES
ABDUCTOR POLLICIS BREVIS
•ORIGON.: Flexor retinaculum of wrist , scaphoid &
trapezium
•INSERTION.: Base of proximal phalanx of thumb
•NERVE SUPPLY: Median
•ACTION: Abducts the thumb at metacarpophalangeal
joint
(M.P.J)
THENAR MUSCLES
FLEXOR POLLICIS BREVIS
•ORI.: Flexor retinaculum
trapezium
•INS: Base of proximal phalanx of thumb
•N.S:Median
• ACT: Flexes the thumb at M.P.J
THENAR MUSCLES
OPPONENS POLLICIS
•ORI.: Trapezium & flexor retinaculum
•INS: Lateral border of shaft of 1st metacarpal
•N.S.: Median
•ACT.: Opposes thumb to other digits
MUSCLE OF THUMB
(not included in thenar group)
ADDUCTOR POLLICIS
•ORI: Obliquehead: capitate, 2nd & 3rd metacarpals
Transverse head: shaft of 3rd metacarpal
•INS: proximal phalanx of thumb
•N.S: deep branch of ulnar
•ACT: adducts the thumb
HYPOTHENAR MUSCLES
•
Group of three muscles
•
Control the motion of the little finger.
•
The three muscles are:
•
Abductor digiti minimi
• Flexor digiti minimi
• Opponens digitiminimi
HYPOTHENAR MUSCLES
ABDUCTOR DIGITI MINIMI
•ORI.:Pisiform
•INS.: Base of proximal phalanx of little
•N.S: Deep br. of ulnar
•ACT: Abducts little finger at M.P.J
finger
HYPOTHENAR MUSCLES
FLEXOR DIGITI MINIMI
•ORI.: Flexor retinaculum
hook of hamate
•INS.: Base of proximal phalanx of little finger
•N.S: Deep br. of ulnar
•ACT: Flexes little finger at M.P.J
HYPOTHENAR MUSCLES
OPPONENS DIGITI MINIMI
•ORI.Flexor retinaculum
hook of hamate
•INS.: Medial border of shaft of 5th metacarpal
•N.S: Deep br. of Ulnar
•ACT: Opposes little finger to other digits
LUMBRICALS
I, II,III & IV
(from lateral to medial)
•
ORI:tendons of flexor digitorum profundus
•
INS:lateral aspect of corresponding extensor expansion
•
I, II by Median & III, IV by ulnar
•
Flex the M.P.J, extend the interphalangeal joints
•
PALMAR INTEROSSEI(I,2,3)
st
1
ORI: Medial side of2ndmetacarpal,
INS: Medial side of base of proximal phalanx of index finger
2nd
ORI: lateral side of 4th metacarpal,
INS:Lateral side of base of proximal phalanx of ring finger
3rd
ORI: lateral side of 5th metacarpal,
INS:Medial side of base of proximal phalanx of little finger
•
•
DORSAL INTEROSSEI(1,2,3,4)
ORI.: All 4 arise by two heads , one from each matacarpal bone
bounding the interosseous space
INS: 1&2, lateral side of base of proximal phalanx of index & middle
fingers resp.
3&4 lateral side of base of proximal phalanx of index & middle fingers
resp.( all into corresponding ext. expansion also)
PALMAR & DORSAL INTEROSSEI
Nerve supply
• All interossei supplied by deep branch of ulnar nerve
Actions
•Palmar interossoi. Adducts the fingers towards center of middle finger
•Dorsal interossi. Abducts the fingers towards center of middle finger
•All flexes M.P.J & extends interphalangeal joints
MOVEMENTS OF THUMB
MOVEMENTS OF THUMB
EXTENSION
•
Extensor
pollicislongus,
•
Extensor pollicis brevis
FLEXION
•
Flexor pollicis longus,
•
Flexor pollicis brevis
MOVEMENTS OF THUMB
ADDUCTION
•
Adductor pollicis
ABDUCTION
•
Abductor pollicis longus
•
Abductor pollicis brevis
MOVEMENTS OF THUMB
OPPOSITION
•Movement of thumb across the palm so that its tip comes in contact with
tip of any other finger
•Produced by opponens pollicis
ANATOMICAL SNUFFBOX
•Concavity on radial side of wrist that appears when thumb is fully extended
Boundaries
• Medial:
Extensor pollicis longus
•Laterally:
Extensor pollicis brevis
Abductor pollicis longus
•
ANATOMICAL SNUFFBOX
Radial artery running in the floor of the
snuffbox
•
Cutaneous branches of radial nerve &
cephalic vein lie in the fascia forming roof.
•
Bony points palpable are: radial styloid,
scaphoid trapezium, base of thumb
metacarpal
•
•
•
•
•
•
•
•
•
DUPUYTREN'S CONTRACTURE OR
PALMAR FIBROMATOSIS
Fixed flexion contracture of the hand
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.
Progresses slowly and is usually painless
MALLET FINGER
An injury of the extensor digitorum tendon of the fingers at the distal
interphalangeal joint (DIP)
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)
•
•
•
•
•
REFERENCES
Clinically oriented anatomy
6th edition
Keith L. Moore
Ch. 6 Upper Limb
Pgs. # 771-793
-------------------------------------------------------------------------------------------------------------------------------