Transcript Muscles of the Wrist and Hand

Myology
Myology of the
Wrist and Hand
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Anatomical Review Distal Ulna and
Radius (Notes in Lecture 3)
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Carpals, Metacarpals, and Phalanges
• Wrist:
– Consists of eight small bones called carpals
– Two rows
• Proximal row: Scaphoid, Lunate, Triquetrum, and
Pisiform
• Distal row: Trapezium, Trapezoid, Capitate, Hamate
• Palm:
– Consists of the Metacarpals
– Five metacarpals numbered I through V with number I being
the thumb
– Each metacarpal has a base, shaft, and a head
• The base articulates with the carpals while the head
articulates with the phalanges.
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• Fingers:
– 14 phalanges in each hand (singular is phalanx)
– Each phalanx also consists of a base, shaft, and head
– The thumb only contains two phalanges, a proximal and
distal one
– The remaining fingers each contain three phalanges
(proximal, middle, and distal)
– Joints formed between phalanges:
• Proximal interphalangeal joint (PIP)
– Joint formed between proximal and middle
phalanges
• Distal interphalangeal joint (DIP)
– Joint formed between middle and distal phalanges
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Anatomical Review of the Hand
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Articular Anatomy of the Wrist
The Wrist and hand are composed of 29 bones forming more than
20 joints. This allows us to perform fine delicate motor skills to
forceful activity
2 joints make up the wrist:
Radiocarpal: elliptical joint formed by the concavity of
the radius and the convexity formed by the scaphoid and lunate.
Ulnarcarpal joint: not a true articulation between the ulna and
triquetrum. This articulation gives stability to the wrist.
Movement within this joint has not been clearly defined.
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Articular Anatomy of the Hand
Four joints make up the hand:
1. Midcarpal joints: Gliding joints between carpal bones
2. Carpometacarpal joints:
a. Carpometacarpal joint I: Rotated 90 degrees from metacarpal II.
A Saddle joint allows for flexion/extension and abduction and
adduction.
b. Carpometacarpal joints II through IV: Gliding joints allowing
slight sliding and flexion/extension.
3. Metocarpophalangeal joints: Ellipsoidal joints between the
metacarpals and the proximal phalanges allowing for
flexion/extension and abduction/adduction.
4. Interphalangeal joints: Hinge joints between the phalanges
allowing for flexion and extension
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Soft Tissue of the Wrist and Hand
Radiocarpal Ligament: Connects the styloid process of the radius and
distal aspect of the ulna to the scaphoid bone.
Ulnar Collateral Ligament: attaches the styloid process of the ulna to
the pisiform
Radial Collateral Ligament: Attaches the styloid process of the radius
to the radial side of the scaphoid and trapezium
Flexor retinaculum: Wide thick ligament connecting the pisiform and
hamate to the scaphoid and trapezium
Palmar aponeurosis: formed from the deep fascia of the anterior hand,
extending from the flexor retinaculum to the four fingers.
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Ranges of Motion of the Wrist
Each student should be able to describe and
demonstrate the following movements:
1.
2.
3.
4.
5.
Wrist flexion
Wrist extension
Abduction (Radial Deviation)
Adduction (Ulnar Deviation)
Wrist Circumduction
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Ranges of Motion of the Fingers
Each student should be able to describe and
demonstrate the following movements:
1.
2.
3.
4.
5.
Finger flexion
Finger extension
Finger abduction
Finger adduction
Finger circumduction
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Ranges of Motion of the Thumb
Each student should be able to describe and
demonstrate the following movements:
1.
2.
3.
4.
5.
Thumb flexion
Thumb extension
Thumb abduction
Thumb adduction
Thumb circumduction
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Palpation of the wrist and
fingers
Carpals: Sitting; Locate the ulnar and radial styloid processes, slide your fingers distally, and then
passively move the wrist in all directions and feel the carpals shift around a bit.
Pisiform: Sitting; Locate the anterior wrist crease, move your fingers toward the pinky side, feel for
the rounded shaped pisiform under the tissue of the palm.
Hook of the Hamate: Sitting; Locate the pisiform again, draw an imaginary line from the pisiform to
the index finger. Slide off the pisiform toward the index finger, about 3/4 of an inch from the pisiform
feel for a small raised area.
Metacarpals: Sitting; Palpate the bones of the palm both on the anterior and posterior surfaces.
Feel the bases at the carpometacarpal joints, the shafts, and the enlarged heads at the
metacarpophalangeal joints.
Phalanges: Sitting; Locate the distal metacarpals again, then move distal palpating all three
phalanges of the fingers (proximal, middle, and distal). Feel for the base, shafts, and heads of each
phalange.
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Anterior extrinsic muscles that move the
wrist & hand
Flexor Carpi Radialis
Palmaris Longus
Superficial layer
Flexor Carpi Ulnaris
Flexor Digitorum Superficialis Intermediate layer
Flexor Digitorum Profundus
Deep
layer
Flexor Pollicus Longus
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Flexor Carpi Radialis
O: Medial epicondyle (via common flexor
tendon) of the humerus
I: Base of the anterior aspect of the
2nd and 3rd metacarpals
A: Flexion and radial deviation of the wrist.
Assists in flexion and pronation of the
forearm
N: Median nerve
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Palmaris Longus
O: Medial epicondyle (via
common flexor tendon) of
the humerus
I: Palmar aponeurosis of the
hand
A: Flexes the wrist. Assists in
flexion of the elbow
N: Median nerve
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Flexor Carpi Ulnaris
O: Humeral Head: Medial
epicondyle (via common flexor
tendon) of the humerus.
Ulnar Head: olecranon process
of the ulna
I: Base of the 5th metacarpal,
pisiform, and hook of hamate
A: Flexion and ulnar deviation of
the wrist. Assists in flexion of 3
the elbow.
N: Ulnar
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Flexor Digitorum Superficialis
O: Humeroulnar Head: Medial
epicondyle (via common flexor
tendon) of the humerus.
Radial Head: Anterior aspect of the
mid-shaft of the radius
I: Anterior surfaces of the middle
phalanges of the 2nd through 5th digits
at the PIP and MP’s. Assists in flexion
of the elbow
A: Flexion of the wrist and flexion of the 2nd
through 5th digits
N: Median nerve
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Flexor Digitorum Profundus
O: Mid shaft of the ulna and
interosseous membrane
I: anterior surface of the distal
phalanges of 2nd through 5th digits
A: Flexion of the wrist and flexion of
the 2nd through 5th digits at the DIP.
Assists in flexion of the wrist
N.
Median and Ulnar nerves
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Flexor Pollicus Longus
O: Anterior aspect of the mid-shaft
of the radius
I: Distal phalanx of the thumb
A: Flexes the wrist and flexion of
the thumb
N: Median nerve
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Posterior extrinsic muscles that
move the wrist and hand
Extensor Carpi Radialis Longus
Extensor Carpi Radialis Brevis
Extensor Carpi Ulnaris
Extensor Digitorum Communis
Extensor Digiti Minimi
Abductor Pollicis Longus
Superficial Muscles
Extensor Pollicis Brevis
Extensor Pollicis Longus
Extensor Indicis
Deep Muscles
Extensor Carpi Radialis Longus
O: Lateral supracondylar ridge
of the humerus
I: Base of the posterior aspect
of
the 2nd metacarpal
A: Extension and radial
deviation of the wrist
N: Radial nerve
Extensor Carpi Radialis Brevis
O: Lateral epicondyle of the
humerus (via the
common extensor
tendon)
I: Base of the posterior
aspect of the 3rd
metacarpal
A: Extension and radial
deviation of the wrist
N: Radial nerve
Extensor Carpi Ulnaris
O: Lateral epicondyle of the
humerus (via the common
extensor tendon)
I: Base of the posterior
aspect of the 5th metacarpal
A: Extension and ulnar deviation of
the wrist
N: Radial nerve
Extensor Digitorum Communis
O: Lateral epicondyle of the humerus
(via the common extensor
tendon)
I: Phalanges of 2nd through the
5th digits
A: Extension of the wrist and
extension of the 2nd – 5th digits
N: Radial nerve
Extensor Digiti Minimi
O: Lateral epicondyle of the
humerus (via the common
extensor tendon)
I: Phalanx of the 5th digit
A: Extension of the pinky
N: Radial nerve
Abductor Pollicis Longus
O: Posterior radius and ulna
I: Base of the first metacarpal
A: Abduction of the thumb
N: Radial nerve
Extensor Pollicis Brevis
O: Posterior radius and
Interosseous membrane
I: Base of the phalanx of the
thumb
A: Extension of the thumb
N: Radial nerve
Extensor Pollicis Longus
O: Posterior ulna and
Interosseous membrane
I: Distal phalanx of the thumb
A: Extension of the thumb
N: Radial nerve
Extensor Indicis
O: Posterior ulna and
Interosseous membrane
I: Index finger
A: Extension of the index finger
N: Radial nerve
Intrinsic Muscles of the Hand:
Thenar Group
Abductor pollicis brevis
Opponens pollicis
Flexor pollicis brevis
Adductor pollicis
All thenar muscles originate on carpal bones and insert into the
thumb, hence they are agonists to thumb movement.
All thenar muscles are innervated by the median nerve, with the
exception of the adductor pollicis which innervated by the ulnar
nerve.
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Abductor pollicis brevis
O: Scaphoid and trapezium
I: Proximal phalanx of the
thumb
A: Abduction of the thumb
N: Median nerve
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Opponens pollicis
O: Trapezium
I: Lateral shaft of the 1st
metacarpal
A: Opposition of the thumb
(flexion at MCP and
phalangeal joint)
N: Median nerve
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Flexor pollicis brevis
O: Trapezium
I: Proximal phalanx of the
thumb
A: Flexion of the thumb
N: Median nerve
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Adductor pollicis
O: Transverse Head: shaft of the 3rd
metacarpal
Oblique Head: carpals adjacent to
the bases of the 2nd and 3rd
metacarpals
I: Base of the proximal phalanx of
the thumb
A: Adduction of the thumb
N: Ulnar nerve
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Intrinsic Muscles of the Hand:
Hypothenar Group
Palmaris Brevis
Abductor Digiti Minimi
Flexor Digiti Minimi
Opponens Digiti Minimi
All hypothenar muscles originate on the carpal bones and
insert into the pinky
All hypothenar muscles are innervated by the ulnar nerve
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Palmaris Brevis
: Palmar aponeurosis
O
I: Skin of the ulnar aspect of
the hand
A: Wrinkles skin of the palm
N: Ulnar nerve
Note: Palmaris brevis overlies the three other hypothenar muscles and is
relatively unimportant, except that it covers and protects the ulnar nerve
and artery
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Abductor Digiti Minimi Manus
O: Pisiform
I: Proximal phalanx of the pinky
A: Abducts the pinky
N: Ulnar nerve
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Flexor Digiti Minimi Manus
O: Hook of hamate
I: Proximal phalanx of the pinky
A: Flexion of the pinky
N: Ulnar nerve
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Opponens Digiti Minimi
O: Hook of hamate
I: Ulnar border of the 5th
metacarpal
A: Opposition of the pinky
N: Ulnar nerve
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Intrinsic Muscles of the Hand:
Mid-Palmar Group
Lumbricales Manus
Dorsal Interossei Manus
Palmar Interossei Manus
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Lumbricales Manus
O: Distal tendons of the flexor digitorum
profundus
I: Extensor expansion of the 2nd through
5th fingers at proximal phalanges
A: Flexion of the fingers at MCP joints
and extension of the PIP and DIP’s
N: Median nerve: 1st and 2nd lumbricales
Ulnar nerve: 3rd and 4th lumbricales
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Dorsal Interossei Manus
O: Dorsal aspect of the metacarpals of
the 2nd, 3rd, and 4th fingers
I: Base of the proximal
phalanges to extensor
expansion of 2nd, 3rd, and
4th fingers
A: Abduction of 2nd, 3rd, and 4th fingers
(DAB).
Dorsal interossei also assist
Lumbricales in MCP flexion and
PIP/DIP extension
N: Ulnar nerve
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Palmar Interossei Manus
O: Palmar aspect of the 2nd, 4th, and 5th
metacarpals
I: Base of the proximal
phalanges to extensor expansion of 2nd, 4th,
and 5th fingers
A: Adduction of 2nd, 4th, and 5th fingers
(PAD).
Palmar interossei also assist Lumbricales
in MCP flexion and PIP/DIP extension
N: Ulnar nerve
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