Lecture 8 Flashcards
What is the innervation of all posterior forearm compartment muscles?
Radial nerve
What is the origin and insertion of brachioradialis?
origin: proximal 2/3 of lateral supracondylar ridge of humerus
insertion: lateral surface of distal end of radius proximal to styloid process
Where do majority (not all) posterior forearm compartment muscles originate?
common extensor tendon on lateral epicondyle
What is the action of brachioradialis?
flexion of forearm (mid-pronation)
What is the innervation of brachioradialis ?
radial nerve
What is the origin and insertion of extensor carpi radialis longus?
Ori: Distal 1/3 of lateral supracondylar ridge of humerus
Ins: Base of 2nd metacarpal bone
What is one of the only muscles of the superficial layer of the posterior compartment of the forearm that does not go to the common extensor tendon?
extensor carpi radialis longus
What is the function of extensor carpi radialis longus?
Extension of hand at wrist
Radial deviation (abduction) of wrist
Extension of elbow (weak)
What is the innervation of extensor carpi radialis longus?
radial nerve
What is the origin and insertion of extensor carpi radialis brevis?
Ori: Lateral epicondyle of humerus (via common extensor tendon)
Ins: Base of 3rd metacarpal bone
What is the function of extensor carpi radialis brevis?
Extension of hand at wrist
Radial deviation (abduction) of wrist
What is the innervation of extensor carpi radialis brevis?
radial nerve
Who composes the Mobile Was of 3?
brachioradialis, extensor carpi radialis longus and brevis
What is the origin and insertion of extensor digitorum?
Ori: Lateral epicondyle of humerus (via common extensor tendon)
Ins: Distal and middle phalanges of fingers #2 – 5
(via its dorsal digital expansion)
What is the function of extensor digitorum?
Extension of fingers 2-5 at MCP, PIP, DIP joints
Extension of hand at wrist
Extension of elbow (weak)
What is the innervation of extensor digitorum?
radial nerve
What is the origin and insertion of extensor digiti minimi?
Ori: Lateral epicondyle of humerus (via common extensor tendon)
Ins: Middle and distal phalanges of little finger (via its dorsal digital expansion)
what is the function of extensor digiti minimi?
extension of finger 5 at MCP, PIP, DIP joints
Extension of hand at wrist
Extension of elbow (weak)
What is the innervation of extensor digiti minimi?
radial nerve
What is the origin and insertion of extensor carpi ulnaris?
Ori:
- Lateral epicondyle of humerus (via common extensor tendon)
- Posterior border of ulna
Ins: Base of 5th metacarpal bone.
What is the function of extensor carpi ulnaris?
Extension of hand at wrist
Ulnar deviation (adduction) of wrist
Extension of elbow (weak)
What is the innervation of extensor carpi ulnaris?
radial nerve
What is the origin and insertion of aconeus?
Ori: Lateral epicondyle of humerus
Ins:
- Olecranon process of ulna
- Proximal of posterior surface of ulna
What is the action of aconeus?
extension of forearm at elbow (weak)
What is the innervation of anconeus?
radial nerve
What is the origin and insertion of supinator?
Ori:
- Supinator crest of ulna
- Lateral epicondyle of humerus
Ins: Proximal 1/3 of lateral surface of radius
What is the function of supinator?
supination of forearm
What is the innervation of supinator?
radial nerve
What is the origin and insertion of abductor pollicis longus?
Ori: The middle of posterior surface of radius, ulna, and interosseous membrane
Ins: Base of the 1st metacarpal
What is the function of abductor pollicis longus?
Abduction of thumb at carpometacarpal joint
Extension of thumb of carpometacarpal joint
Radial deviation of hand at wrist (weak)
What is the innervation of abductor pollicis longus?
radial nerve
What is the origin and insertion of extensor pollicis brevis?
Ori: Distal 1/3 of posterior surface of radius and interosseous membrane
Ins: Base of proximal phalanx of thumb
What is the function of extensor pollicis brevis?
Extension of thumb at carpometacarpal and metacarpophalangeal joint
Extension of hand at wrist
Radial deviation (abduction) of hand (weak)
What is the innervation of extensor pollicis brevis?
radial nerve
What is the origin and insertion of extensor pollicis longus?
Ori: Middle 1/3 of posterior surface of ulna and interosseous membrane
Ins: Base of distal phalanx of thumb
What is the function of extensor pollicis longus?
Extension of thumb at carpometacarpal and metacarpophalangeal and interphalangeal joint
Extension of hand at wrist
Radial deviation (abduction) of hand (weak)
What is the innervation of extensor pollicis longus?
radial nerve
What is the origin and insertion of extensor indicis?
Ori: Distal 1/3 of posterior surface of ulna and interosseous membrane
Ins: Dorsal digital expansion of the 2nd finger
What is the action of extensor indicis?
Extension of Digit 2 (index finger) at metacarpophalangeal and interphalangeal joints (proximal and distal)
Extension of hand at wrist
What is the innervation of extensor indicis?
radial nerve
What travels inside the snuff box?
radial artery
scaphoid & trapezium
What is the only muscle that runs on the anterior lateral compartment?
brachioradialis
How many tendons does the extensor digitorum split into?
4
What muscle allows you to extend pinky without anything else happening?
extensor digiti minimi
What is the blend of tendon insertions on the dorsal aspect of the digits called?
dorsal digital expansions or extensor hood
What muscle helps the triceps?
anconeus
What muscle helps biceps?
supinator
What is supinator syndrome?
Compression in any one who overworks supinator –> can clamp down on this nerve and lead to issues
What muscle allows for extra movement at the index finger?
extensor indicis
What muscles make up the lateral border of the snuff box?
abductor pollicis longus & extensor pollicis brevis
What muscle makes up the medial border of the snuff box?
extensor pollicis longus
What is another name for golf elbow?
medial epicondylitis
What muscles are affected in medial epicondylitis?
all muscles that originate at common flexor tendon
What is another name for tennis elbow?
lateral epicondylitis
What muscles are affected in lateral epicondylitis?
all muscles that originate on common extensor tendon
Where is weakness occur in both tennis and golf elbow?
hand
What muscles are affected in radial nerve injury?
deltoid, teres minor, distal triceps, anconeus, superficial and deep layers of forearm muscles
What movements are affected in radial nerve injury?
weakness in abduction and external rotation of shoulder
loss of extension: elbow, wrist, fingers
weakness in supination
What sensory deficits may be present in radial nerve injury?
Loss of sensation to lateral aspect of shoulder, posterior forearm and lateral 3.5 digits (dorsal surface) –> motor and sensory loss
What long term deficits might occur in radial nerve injury?
wrist drop deformity
What is radial nerve injury?
damage to posterior cord of brachial plexus
What are the 3 parts of the hand?
wrist, metacarpus, fingers
What are the movements of the thumb defined at?
right angles (90 degrees)
What is the carpal arch formed by?
carpal bones
What tendons pass through the carpal tunnel?
9: flexor digititorum profundus, flexor digititorum superficialias, flexor pollicis longus
Median nerve
What are the intrinsic muscles of the hand divided into?
thenar
hypothenar
central
What does intrinsic muscles mean?
both origin and region are coming from same region
What are the thenar muscles?
abductor pollicis brevis
flexor pollicis brevis
opponens pollicis
What are the thenar muscles innervated by?
median nerve
Flexor pollicis brevis also recieves a branch from what nerve?
ulnar
What are the hypothenar muscles?
abductor digiti minimi
flexor digiti minimi brevis
opponens digiti minimi
palmaris brevis
what is the innervation of the hypothenar muscles?
ulnar nerve
What are the central muscles of the hand?
lumbricals (4)
dorsal interosseous (4)
palmar interosseous (3)
adductor pollicis
What is the innervation of the central muscles?
ulnar nerve: dorsal interosseous, palmar interosseous, adductor pollicis
median and ulnar: lumbricals
What is the origin and insertion of abductor pollicis brevis?
Ori:
- Flexor retinaculum
- Tubercle of scaphoid
- Tubercle of trapezium
Ins: Lateral side of the base of proximal phalanx of thumb
What is the action of the abductor pollicis brevis?
abduction of thumb
What does the Palmar aponeurosis protect?
soft tissue, nerves, and blood vessels on palmar side of hand
What is the origin and insertion of flexor pollicis brevis?
Ori:
- Flexor retinaculum
- Trapezium
Ins: Lateral side of the base of proximal phalanx of thumb.
What is the function of the flexor pollicis brevis?
flexion of thumb
What is the origin and insertion of opponens pollicis?
Ori:
- Flexor retinaculum
- Trapezium
Ins: 1st metacarpal
What is the function of opponens pollicis?
opposition of thumb
What is the origin and insertion of palmaris brevis?
Ori: palmar aponeurosis.
Ins: skin of the medial side of the hand.
What is the function of the palmaris brevis?
wrinkles skin to improve grip
What is the origin and insertion of abductor digiti minimi?
Ori: Pisiform
Ins: Medial side of base of proximal phalanx of little finger
What is the function of the abductor digiti minimi?
abductor of little finger
What is the origin and insertion of flexor digiti minimi brevis?
Ori:
- Flexor retinaculum
- Hook of hamate
Ins: Medial side of the base of proximal phalanx of 5th finger
What is the function of flexor digiti minimi brevis?
flexion of little finger
What is the origin and insertion of opponens digiti minimi?
Ori:
- Flexor retinaculum
- Hook of hamate
Ins: 5th metacarpal bone
What is the function of opponens digiti minimi?
opposition of little finger
What is the origin and insertion of adductor pollicis?
Ori:
Oblique head:
- Base of 2nd & 3rd metacarpal bones
- Capitate
Transverse head:
- Ant. surface of 3rd metacarpal bone
Ins: Both heads: medial side of the base of proximal phalanx of thumb
What is the function of the adductor pollicis?
adduction of thumb
What muscle tendon contains the sesamoid bone?
adductor pollicis
What is the origin and insertion of the lumbrical muscles?
Ori: Tendon of the Flexor Digitorum Profundus (FDP) of each finger
Ins: Dorsal digital expansion of four medial fingers
- Lumbrical #1: into the dorsal digital expansion of the index finger (finger #2)
- Lumbrical #2: into the dorsal digital expansion of the middle finger (finger #3)
- Lumbrical #3: into the dorsal digital expansion of the ring finger (finger #4)
- Lumbrical #4: into the dorsal digital expansion of the little finger (finger #5)
What is the function of the lumbrical muscles?
Flexion of fingers 2-5 @ MCP joints
Extension of fingers 2-5 @ PIP and DIP joints
How many tendon does the lumbrical muscles consist of?
4
Most of the bulk of the 1st web is made by which muscle?
adductor pollicis
What is the innervation of the lumbrical muscles?
median (1&2) and ulna (3&4)
What is the origin and insertion of the dorsal interosseous muscles?
Ori: Adjacent sides of metacarpals.
Ins: Base of proximal phalanges and dorsal digital expansion of fingers (#2, #3,and #4)
- Dorsal interosseous #1 to the lateral side of the index finger
- Dorsal interosseous # 2 to the lateral side of the middle finger
- Dorsal interosseous # 3 to the medial side of the middle finger
- Dorsal interosseous # 4 to the medial side of the ring finger
What is the function of the dorsal interosseous muscles?
Abduction of fingers 2-4 @MCP joints
Flexion of fingers 2-3 @ MCP joints
Extension of fingers 2-3 @ PIP & DIP joints
What is the origin and insertion of palmar interosseous muscles?
Ori: Anterior side of metacarpal of fingers #2, 4, and 5
Palmar interosseous #1: metacarpal #2
Palmar interosseous #2: metacarpal #4
Palmar interosseous #3: metacarpal #5
Ins: Base of proximal phalanges and dorsal digital expansion of fingers (#2, 4,and 5)
Palmar interosseous # 1 to the index finger (finger #2)
Palmar interosseous # 2 to the lateral ring finger (finger #4)
Palmar interosseous # 3 to the little finger (finger #5)
What is the function of the palmar interosseous muscles?
Adduction of fingers 2, 4, 5 @ MCP joints
Flexion of fingers 2, 4, 5 @ MCP joints
Extension of finger 2, 4, 5 @ DIP, PIP joints
