Muscles And Fasciae Of The Upper Limb part 3 Flashcards
SUPERFICIAL LAYER (POSTERIOR COMPARTMENT) All extend as tendons into the hand except:
- Brachioradialis
* Anconeus
BRACHIORADIALIS Origin:
proximal part of the supraepicondylar ridge of the humerus
BRACHIORADIALIS Insertion:
lateral side of the distal end of the radius just proximal to the radial styloid process
BRACHIORADIALIS Innervation::
radial nerve
BRACHIORADIALIS Origin:
accessory flexor of elbow joint
forms the lateral boundary of the cubital fossa.
BRACHIORADIALIS
EXTENSOR CARPI RADIALIS LONGUS
Origin:
o distal part of the supraepicondylar ridge
o lateral epicondyle of the humerus
EXTENSOR CARPI RADIALIS LONGUS
Insertion:
dorsal surface of the base of metacarpal II
EXTENSOR CARPI RADIALIS LONGUS
Innervation:
deep branch of the radial nerve
EXTENSOR CARPI RADIALIS LONGUS
Action:
extends and abducts the wrist
EXTENSOR CARPI RADIALIS BREVIS Origin:
lateral epicondyle of the humerus
EXTENSOR CARPI RADIALIS BREVIS Insertion:
adjacent dorsal surfaces of the bases of metacarpals II and III
EXTENSOR CARPI RADIALIS BREVIS Innervation:
deep branch of the radial nerve
EXTENSOR CARPI RADIALIS BREVIS Action:
extends and abducts the wrist
EXTENSOR DIGITORUM Origin:
lateral epicondyle of the humerus
EXTENSOR DIGITORUM Insertion:
via the triangular-shaped connective tissue aponeurosis (extensor hood) into the base of the dorsal surfaces of the middle and distal phalanges
EXTENSOR DIGITORUM Innervation:
posterior interosseous nerve
EXTENSOR DIGITORUM Action:
Major extensor of the 4 fingers (index, middle, ring, and little fingers
EXTENSOR DIGITORUM
o It results from the distal interphalangeal joint suddenly being forced into extreme flexion
o Sudden severe tension on a long extensor tendon, avulse attachment to the phalanx
o Treatment: use of finger splint to approximate the edges of the torn tendon
Mallet or baseball finger:
EXTENSOR DIGITI MINIMI Origin:
medial to extensor digitorum in the forearm arising from lateral epicondyle of the humerus
EXTENSOR DIGITI MINIMI Insertion:
together with the tendon of extensor digitorum into the dorsal digital expansion of the little finger
EXTENSOR DIGITI MINIMI Innervation:
posterior interosseous nerve
EXTENSOR DIGITI MINIMI Action:
accessory extensor of the small finger
EXTENSOR CARPI ULNARIS Location:
medial to the extensor digiti minimi
EXTENSOR CARPI ULNARIS Location:
lateral epicondyle of the humerus
EXTENSOR CARPI ULNARIS Origin:
medial
side of the base of
metacarpal V
EXTENSOR CARPI ULNARIS Insertion:
posterior interosseous nerve
EXTENSOR CARPI ULNARIS Innervation:
extends and adducts the wrist
ANCONEUS Location:
most medial
of the superficial extensors
ANCONEUS Shape:
triangular
ANCONEUS Origin:
lateral
epicondyle of the humerus
ANCONEUS Insertion:
o Posterolateral surface
of the olecranon
o Posterior surface of the ulna
ANCONEUS Innervation:
branch of the radial nerve
ANCONEUS Action:
abducts the ulna during pronation & accessory extensor of the elbow joint
5 muscles in the DEEP LAYER (POSTERIOR COMPARTMENT)
o Supinator o Abductor pollicis longus o Extensor pollicis brevis o Extensor pollicis longus o Extensor indicis
All deep layer muscles originate from the posterior surfaces of the radius, ulna, interosseous membrane, and pass into the thumb & fingers except: __
supinator muscle
3 muscles that emerge from between extensor digitorum and extensor carpi radialis brevis tendons of the superficial layer and pass into the thumb:
o Abductor pollicis longus
o Extensor pollicis brevis
o Extensor pollicis longus
2 of the three outcropping muscles that form a distinct muscular bulge in the distal posterolateral surface of the forearm:
o Abductor pollicis longus
o Extensor pollicis brevis
All muscles of the deep layer are innervated by the __ (continuation of radial nerve deep branch)
posterior interosseous nerve
SUPINATOR
Has 2 heads of origin:
o Superficial humeral head
o Deep ulnar head
SUPINATOR Insertion:
proximal aspect of radius
SUPINATOR Innervation:
posterior interosseous nerve that innervates the medial head of the triceps brachii
SUPINATOR Action:
supinates forearm
ABDUCTOR POLLICIS LONGUS Origin:
o Proximal posterior surfaces of the radius & ulna
o Interosseous membrane
ABDUCTOR POLLICIS LONGUS Insertion:
lateral side of the base of metacarpal I
ABDUCTOR POLLICIS LONGUS Innervation:
posterior interosseous nerve (C7 and C8)
ABDUCTOR POLLICIS LONGUS Action:
abduct the thumb at the joint between metacarpal I and trapezium bones
It contributes to the lateral border of the anatomical snuffbox
Abductor pollicis longus tendon
EXTENSOR POLLICIS BREVIS Origin:
distal to the origin of abductor pollicis longus from the posterior surface of the radius and interosseous membrane
EXTENSOR POLLICIS BREVIS Insertion:
dorsal surface of the base of the proximal phalanx
EXTENSOR POLLICIS BREVIS Innervation:
Posterior interosseous nerve
EXTENSOR POLLICIS BREVIS Action:
extends the MCP and carpometacarpal joints of the thumb
contributes as well to the lateral border of the anatomical snuffbox
Extensor pollicis brevis tendon
- Occurs when the tendons around the base of thumb (APL and EPB) are irritated or constricted
- Noticeable when forming a fist; grasping; gripping; turning the wrist
- Characterized by tendon swelling and causes pain and tenderness along the thumb side of the wrist
De Quervain’s Tenosynovitis
De Quervain’s Tenosynovitis
Dx: placing thumb against your hand. Making a fist with your fingers closed over your thumb and then bending wrist toward little finger
Finkelstein test
EXTENSOR POLLICIS LONGUS Origin:
posterior surface of the ulna & adjacent interosseous membrane
EXTENSOR POLLICIS LONGUS Insertion:
long tendon into the dorsal surface of distal phalanx of the thumb
EXTENSOR POLLICIS LONGUS Action:
Extension of all joints of the thumb
EXTENSOR POLLICIS LONGUS Innervation:
posterior interosseous nerve (C7 and C8)
Extensor pollicis longus (EPL) and Extensor pollicis brevis (EPB) tendon
Extensor pollicis longus (EPL) and Extensor pollicis brevis (EPB) tendon
EXTENSOR INDICIS Origin:
adjacent interosseous membrane & distal to extensor pollicis longus from the posterior surface of the ulna
EXTENSOR INDICIS Insertion:
extensor hood of the index finger with the tendon of extensor digitorum
EXTENSOR INDICIS Innervation:
posterior interosseous nerve (C7 and C8)
EXTENSOR INDICIS Action:
accessory extensor of the index finger
SURFACE ANATOMY OF THE FOREARM
▪ Medial part: flexor muscles
▪ Lateral part: extensor muscles
FUNCTIONAL POSITIONS OF THE HAND
Power Grip Hook Grip Precision Handling Grip Pinching Position of Rest
▪ forcible motions of the digits acting against the palm.
▪ the fingers are wrapped around an object with counter pressure from the thumb like when grasping a cylindrical structure.
▪ it involves the:
• long flexors of the fingers
• intrinsic muscles in the palm
• extensors of the wrist.
Power Grip
▪ posture of the hand used when carrying a briefcase.
▪ consumes less energy, involving mainly the long flexors of the fingers, which are flexed to a varying degree, depending on the size of the object that is grasped.
Hook Grip
▪ involves a change in the position of a handled object that requires fine control of the movements of the fingers and thumb
▪ for example: holding a pencil, manipulating a coin, threading a needle, buttoning a shirt.
▪ Wrist and fingers are held firmly by the long flexor and extensor muscles, and the intrinsic hand muscles perform fine movements of the digits.
Precision Handling Grip
▪ compression of something between the thumb and the index finger
▪ for example, handling a teacup or holding a coin on edge.
Pinching
is assumed by an inactive hand
▪ for example, when the forearm and hand are laid on the table.
▪ is often used when it is necessary to immobilize the wrist and hand in a cast to stabilize a fracture.
Position of Rest
are located entirely in the hand and mainly execute precision movements (‘precision grip’) with the fingers and thumb.
INTRINSIC MUSCLES OF THE HAND
The intrinsic muscles are the:
- Palmaris brevis
- Interossei (Dorsal and Palmar)
- Adductor pollicis
- Thenar muscles
- Hypothenar muscles
- Lumbrical muscles
All of the intrinsic muscles of the hand are innervated by the
deep branch of the ulnar nerve
All of the intrinsic muscles of the hand are innervated by the deep branch of the ulnar nerve except:
3 thenar and 2 lateral lumbrical muscles
3 thenar and 2 lateral lumbrical muscles which are innervated by the
median nerve.
PALMARIS BREVIS Origin:
tendinous fasciculi from the transverse carpal ligament and palmar aponeurosis.
PALMARIS BREVIS Insertion:
skin on the ulnar border of the palm of the hand, occasionally on the pisiform
PALMARIS BREVIS Actions:
tenses the skin of the palm on the ulnar side during a grip action, deepens the hollow of the palm
PALMARIS BREVIS Innervation:
only
muscle innervated by the superficial branch of the ulnar nerve (C8, T1)
INTEROSSEI MUSCLES Divided into two groups
- dorsal interossei,
* palmar interossei
are muscles between and attached to the metacarpals.
INTEROSSEI MUSCLES
INTEROSSEI MUSCLES Insertion:
proximal phalanx of each digit and into the extensor hood.
INTEROSSEI MUSCLES Innervation:
All are innervated by the deep branch of the ulnar nerve
INTEROSSEI MUSCLES actions
o abduct and adduct the digits
o contribute to the complex flexion and extension movements generated by the extensor hoods.
They are unipennate muscles originating from the metacarpals of the digits with which is associated.
Palmar Interossei
o Origin: medial side of the palmar surface of metacarpal I
o Insertion: base of the proximal phalanx of the thumb, extensor hood
First palmar interosseous muscle
o Origin: medial side of metacarpal II
o Insertion: medial side of the dorsal expansion of the index finger
Second palmar interosseous muscle
o Origin: lateral surfaces of metacarpals IV and V
o Insertion: lateral sides of the respective dorsal hoods
o actions:
• adduct the thumb, index, ring, and little fingers
• flexion of the MCP joints
• extension of the PIP & DIP joints of the fingers through their attachments to the dorsal hoods
Fourth & Fifth palmar of interosseous muscle
LUMBRICAL MUSCLES Origin:
tendons of flexor digitorum profundus
The 1st and 2nd lumbricals are __ muscles associated with index and middle fingers.
unipennate
The 3rd and 4th lumbricals are __ associated with the ring and little fingers.
bipennate
1st and 2nd lumbricals Insertions:
digital branches of the median nerve
3rd and 4th lumbricals Insertions:
deep branch of the ulnar nerve
Large triangular muscle anterior to the plane of the interossei that crosses the palm
ADDUCTOR POLLICIS
ADDUCTOR POLLICIS Origins:
o Transverse head – anterior aspect of the shaft of metacarpal III
o Oblique head – capitate, bases of metacarpals II and III
ADDUCTOR POLLICIS Insertions:
o medial side of the base of the proximal phalanx of the thumb
o extensor hood
ADDUCTOR POLLICIS Actions
o powerful adductor of the thumb and opposes the thumb to the rest of the digits in gripping
THUMB MOVEMENTS
▪ rotated 90 degrees to the other digits.
▪ Abduction and adduction occur in a sagittal plane
▪ Flexion and Extension occur in a coronal plane
▪ Opposition is the most complex movement.
Responsible for the prominent swelling on the lateral side of the palm at the base of the thumb.
(thenar eminence)
▪ Largest of the thenar muscles
OPPONENS POLLICIS
▪ Distal to the abductor policis brevis
FLEXOR POLLICIS BREVIS
▪ There are 3 hypothenar muscles:
o Opponens digiti minimi
o Abductor digiti minimi
o Flexor digiti minimi brevis
lies deep to the other two hypothenar muscles.
OPPONENS DIGITI MINIMI
overlies the opponens digiti minimi.
ABDUCTOR DIGITI MINIMI
Fascia deep surface, which occasionally serves to extend the surface area available for muscular origin, is attached directly or via __
intermuscular septa to the enclosed bones.
Deep fascia which forms the floor of the axilla
AXILLARY FASCIA
Deep fascia which forms a tubular investment of the arm
BRACHIAL FASCIA
BRACHIAL FASCIA Attached to the __ via medial and lateral intermuscular septae
humerus
Deep fascia which form a tubular investment of the forearm muscles
ANTEBRACHIAL FASCIA
ANTEBRACHIAL FASCIA Attached to the __ via the lateral intermuscular septum
radius
divides the forearm into volar and dorsal muscular compartments.
Intermuscular septum together with the radius
o formed by the carpal arch and the flexor retinaculum
o a rigid and confining space that contains the long flexor tendons of the fingers and the thumb and the median nerve
Carpal tunnel
The median nerve is the most sensitive structure in the carpal tunnel and therefore is the most affected.
Carpal Tunnel Syndrome
Carpal Tunnel Syndrome has 2 terminal sensory branches that supply the skin of the hand
- paresthesia (tingling)
* hyposthesia (diminished sensation)
Carpal Tunnel Syndrome may occur in the
lateral 3 ½ digits
Individuals with carpal tunnel syndrome are unable to
oppose the thumb and have difficulty buttoning shirt or blouse as well as gripping things such as a comb.
refers to a deformity in which thumb movements are limited to flexion and extension of the thumb in the plane of the palm
• caused by the inability to oppose and by limited abduction of the thumb
Ape hand
To relieve both the compression and the resulting symptoms, complete surgical division of the flexor retinaculum, a procedure called
carpal tunnel release,
The incision for carpal tunnel release is made toward the medial side of the wrist and flexor retinaculum to avoid possible injury to the
recurrent branch of the median nerve
o thickening of the deep fascia covering the palm of the hand
o composed of very dense connective tissue that extends out into each of the fingers
Palmar Aponeurosis
Dapuytren’s Contracture
o a disease of the palmar fascia resulting in progressive shortening, thickening, and fibrosis of the palmar fascia and aponeurosis
Dapuytren’s Contracture
Dapuytren’s Contracture cause
fibrous degeneration of the longitudinal bands of the palmar aponeurosis
stenosing tenosynovitis
Trigger Finger
a condition in which one of your fingers gets stuck in a bent position.
Trigger Finger
▪ covering the thenar muscle group
▪ blends with the palmar aponeurosis and attaches to the third metacarpal bone as the lateral fibrous septum
▪ defines the thenar compartment of the hand
THENAR FASCIA
▪ covers the hypothenar muscle group
▪ blends with the palmar aponeurosis and attaches to the fifth metacarpal bone as the medial fibrous septum
▪ defines the hypothenar compartment of the hand
HYPOTHENAR FASCIA
CENTRAL COMPARTMENT
In between thenar and hypothenar compartments are:
o Flexor tendons and sheaths
o Lumbricals
o Superficial palmar arterial arch
o Digital vessels and nerves
ADDUCTOR COMPARTMENT
▪ Deepest muscular plane of the palm
▪ Contains:
adductor pollicis
o is responsible for the smooth contour
of the lateral side of the neck and
over the superior aspect of the
shoulder.
Trapezius
o forms much of the muscle mass
underlying the posterior axillary fold
extending obliquely upward from the
trunk to the arm.
Latissimus dorsi
o passes from the inferior angle of the
scapula to the upper humerus and
contributes to the fold laterally.
Teres major
The rounded curve of the shoulder is formed
by the thick __, which is a
frequent site for intramuscular injections.
deltoid muscle
The __ forms the fleshy anterior
axillary fold, which acts as the anterior border
of the axilla.
pectoralis major
The __ and __
form the fleshy posterior axillary fold, which
is the posterior border of the axilla.
latissimus dorsi and teres major muscles
becomes prominent
when the elbow is flexed.
Biceps brachii muscle
Cubital fossa
o biceps brachii tendon
o brachial artery
o median nerve
It is a depression within which the median cubital vein connects the basilic and cephalic veins. ▪ is a common site for venipuncture.
Cubital fossa
formed by the bulk of
the posterior surface of the brachium.
Triceps brachii muscles
The __ is a
rounded lateral projection at the distal end of the
humerus.
lateral epicondyle of the humerus
The __ is palpated easily
along the posterior aspect of the elbow.
olecranon of the ulna
located
approximately at the junction between the
lateral and middle thirds of an imaginary line
drawn transversely across the distal forearm.
tendon of flexor carpi radialis
immediately lateral to this
tendon and this site is used for taking a radial
pulse.
radial artery