Exam 5 - Upper Limb Part 2 - Slides 51 - 143 Flashcards
1
Q
a disorder characterized by catching, snapping, or locking of the involved finger flexor tendon, associated with dysfunction and pain
A
Trigger finger, trigger thumb, trigger digit, stenosing tenosynovitis
2
Q
Caused by a disparity in size between the flexor tendon and the surrounding retinacular pulley system that results in difficulty flexing or extending the finger
A
Trigger finger
3
Q
May affect more than one finger at a time, but usually affects the index, middle, or ring fingers, or the thumb
A
Trigger finger
4
Q
Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis Extensor digitorum Extensor digiti minimi Extensor carpi ulnaris
Comprise?
A
Superficial posterior (extensor) compartment
5
Q
Brachioradialis OIAI?
A
Origin: humerus
Insertion: radius (near styloid process)
Action: flexes forearm at elbow; supinates and pronates forearm (back to neutral). When the forearm is pronated, it tends to supinate when flexed; when the forearm is supinated it tends to pronate. For this reason, it is known as the “beer drinker muscle.”
Innervation: radial nerve
6
Q
elicited during a neurological exam by striking the brachioradialis tendon near its insertion at the base of the wrist near the radial styloid process directly with a reflex hammer, with the patient’s arm relaxed
A
Brachioradialis reflex
7
Q
results in a slight wrist extension and/or radial deviation, supination, and slight elbow flexion
A
Brachioradialis reflex
carried by the radial nerve
8
Q
Extensor Carpi Radialis Longus OIAI?
A
Origin: distal humerus
Insertion: radial posterior hand (posterior side of base of second metacarpal)
Action: extends and abducts hand at wrist joint (radial deviation)
Innervation: radial nerve
9
Q
Extensor Carpi Radialis Brevis OIAI?
A
Origin: lateral epicondyle of humerus via common extensor tendon
Insertion: radial posterior hand (posterior side of base of 3rd metacarpal)
Action: extends and abducts hand at wrist joint (radial deviation)
Innervation: deep radial nerve
10
Q
Extensor Digitorum OIAI?
A
Origin: lateral epicondyle of humerus via common extensor tendon
Insertion: phalanges of digits 2 – 4 or 2 – 5
Action: extends digits 2 – 4 or 2 – 5
Innervation: deep radial nerve
11
Q
Extensor Digiti Minimi OIAI?
A
Origin: lateral epicondyle of humerus via common extensor tendon
Insertion: phalanx of little finger (5th digit)
Action: extends 5th digit
Innervation: deep radial nerve
12
Q
Origin: humerus
Insertion: radius (near styloid process)
Action: flexes forearm at elbow; supinates and pronates forearm (back to neutral). When the forearm is pronated, it tends to supinate when flexed; when the forearm is supinated it tends to pronate. For this reason, it is known as the “beer drinker muscle.”
Innervation: radial nerve
A
Brachioradialis
13
Q
Origin: distal humerus
Insertion: radial posterior hand (posterior side of base of second metacarpal)
Action: extends and abducts hand at wrist joint (radial deviation)
Innervation: radial nerve
A
Extensor Carpi Radialis Longus
14
Q
Origin: lateral epicondyle of humerus via common extensor tendon
Insertion: radial posterior hand (posterior side of base of 3rd metacarpal)
Action: extends and abducts hand at wrist joint (radial deviation)
Innervation: deep radial nerve
A
Extensor Carpi Radialis Brevis
15
Q
Origin: lateral epicondyle of humerus via common extensor tendon
Insertion: phalanges of digits 2 – 4 or 2 – 5
Action: extends digits 2 – 4 or 2 – 5
Innervation: deep radial nerve
A
Extensor Digitorum
16
Q
Origin: lateral epicondyle of humerus via common extensor tendon
Insertion: phalanx of little finger (5th digit)
Action: extends 5th digit
Innervation: deep radial nerve
A
Extensor Digiti Minimi
17
Q
Origin: lateral epicondyle of humerus via common extensor tendon
Insertion: ulnar posterior hand (posterior side of base of 5th metacarpal)
Action: extends and adducts hand at wrist joint (ulnar deviation)
Innervation: deep radial nerve
A
Extensor Carpi Ulnaris
18
Q
Extensor Carpi Ulnaris
A
Origin: lateral epicondyle of humerus via common extensor tendon
Insertion: ulnar posterior hand (posterior side of base of 5th metacarpal)
Action: extends and adducts hand at wrist joint (ulnar deviation)
Innervation: deep radial nerve
19
Q
Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor indicis Supinator
A
Deep posterior (extensor) compartment
20
Q
Origin: posterior radius and ulna (and interosseous membrane)
Insertion: base of thumb (at 1st metacarpal)
Action: abducts and extends thumb
Innervation: deep radial nerve
A
Abductor pollicis longus
21
Q
Abductor pollicis longus
A
Origin: posterior radius and ulna (and interosseous membrane)
Insertion: base of thumb (at 1st metacarpal)
Action: abducts and extends thumb
Innervation: deep radial nerve
22
Q
Origin: posterior radius (and interosseous membrane)
Insertion: proximal phalanx of thumb
Action: extends thumb
Innervation: deep radial nerve
A
Extensor Pollicis Brevis
23
Q
Extensor Pollicis Brevis
A
Origin: posterior radius (and interosseous membrane)
Insertion: proximal phalanx of thumb
Action: extends thumb
Innervation: deep radial nerve
24
Q
Origin: posterior ulna (and interosseous membrane)
Insertion: distal phalanx of thumb
Action: extends thumb
Innervation: deep radial nerve
A
Extensor Pollicis Longus
25
The tendon of extensor pollicis longus crosses the wrist, then turns toward the thumb using the ____ of the radius (Lister’s tubercle) on the distal end of the radius as a pulley
dorsal tubercle
slide 64
26
Extensor Pollicis Longus
Origin: posterior ulna (and interosseous membrane)
Insertion: distal phalanx of thumb
Action: extends thumb
Innervation: deep radial nerve
27
Muscles of the forearm: Note relationship between tendons of extensor carpi radialis brevis and extensor carpi radialis longus, and ____ crossing them.
extensor pollicis longus
slide 65
28
Origin: ulna (and interosseous membrane)
Insertion: index finger (extensor expansion of 2nd digit)
Action: extends 2nd digit (and helps extend hand)
Innervation: deep radial nerve
Extensor Indicis
29
Extensor Indicis
Origin: ulna (and interosseous membrane)
Insertion: index finger (extensor expansion of 2nd digit)
Action: extends 2nd digit (and helps extend hand)
Innervation: deep radial nerve
30
movement of the forearm and hand that rotates the radius medially around its longitudinal axis so that the palm of the hand faces posteriorly, and its dorsum faces anteriorly
Pronation
31
the corresponding movement that causes the palm to face anteriorly (i.e. in the anatomical position)
Supination
32
Pronation is essentially a function of the ___ nerve; supination is a function of the musculocutaneous and ___ nerves
median
radial
33
____ move the radius, so their insertion is on the radius
Pronators
34
Pronators ___ is on the ulna (in general terms)
origin
35
Pronator teres
Pronator quadratus
Brachioradialis
Pronators
36
the ____supinates and pronates back to neutral.
brachioradialis
37
Origin: medial epicondyle of humerus
Insertion: radius
Action: pronates forearm (at elbow)
Innervation: median nerve
Pronator Teres
38
Pronator Teres
Origin: medial epicondyle of humerus
Insertion: radius
Action: pronates forearm (at elbow)
Innervation: median nerve
39
Origin: ulna (distal shaft)
Insertion: radius (distal shaft)
Action: pronates forearm (at radioulnar joint)
Innervation: median nerve
Pronator quadratus
40
Pronator quadratus
Origin: ulna (distal shaft)
Insertion: radius (distal shaft)
Action: pronates forearm (at radioulnar joint)
Innervation: median nerve
41
The supinators move the radius, so their insertion is on the
radius
42
In general terms supinators origin is on the
humerus
43
Supinator muscle
Biceps brachii
Brachioradialis
supinators
44
The supinator muscle and muscles that provide supination are used when . . .
Turning a screw with a screwdriver
45
Origin: humerus (lateral epicondyle) and ulna (proximal portion)
Insertion: proximal radius
Action: supinates forearm
Innervation: deep radial nerve
Supinator
46
Supinator
Origin: humerus (lateral epicondyle) and ulna (proximal portion)
Insertion: proximal radius
Action: supinates forearm
Innervation: deep radial nerve
47
Hey slacker check slide 73
If you don't, you'll fail
48
The brachial artery ends in the inferior part of the cubital fossa where it divides into its two terminal branches:
Ulnar artery
Radial artery
Arteries of the forearm
49
The arteries basically trend with the bones after which they are named
Ulnar artery
Radial artery
Arteries of the forearm
50
Both the radial artery and ulnar artery give off ___ arteries that supply the elbow.
recurrent
51
Both arteries have muscular branches that supply the muscles on their respective sides of the forearm.
Seems logical
52
Superficial veins of the forearm...
Cephalic
Basilic
Median antebrachial
53
Pulse rate is commonly measured where the ___ artery lies on the anterior surface of the distal end of the radius
radial
54
At this radial pulse location the artery can be compressed against the radius where it lies between the tendons of the ___ and abductor pollicis longus
flexor carpi radialis
55
Slide 79 for graphical representation of a portion of the forearm nerves as seen from above
if you know you know
56
flexor carpi ulnaris and flexor digitorum profundus
innervated by the ulnar nerve
| the latter also innervated by the median nerve
57
flexor carpi radialis, palmaris longus, flexor digitorum superficialis, flexor pollicis longus, and flexor digitorum profundus
forearm muscles innervated by the median nerve
| the latter also innervated by the ulnar nerve
58
Radial nerve dysfunction is a form of ___occurring when there is damage to the radial nerve resulting in a problem with movement or sensation of the back of the arm, the forearm, or the hand.
peripheral neuropathy
59
The usual causes of radial nerve dysfunction are direct trauma, ______, or compression of the nerve caused by swelling or injury of nearby body structures. Entrapment involves pressure on the nerve where it passes through a narrow structure.
prolonged pressure on the nerve
60
The radial nerve may be injured at the ___ by direct pressure, such as "crutch palsy," caused by improper use of crutches, or pressure caused by hanging the arm over the back of a chair.
axilla (underarm)
61
The wrist and hand consist of __ bones, many articulations, and 19 intrinsic and 20 extrinsic muscles
28
The surface anatomy comprises dorsal, volar (palmar), radial and ulnar sides
62
The palm is divided into:
thenar, midpalm, and hypothenar areas
63
The antebrachial fascia thickens posteriorly over the distal ends of the radius and ulna to form a transverse band called the ___
extensor retinaculum.
slide 88
64
It retains the extensor tendons in position, and prevents bowstringing (which is a function of retinacula in general)
extensor retinaculum
slide 88
65
In addition to the posterior thickening of the antebrachial fascia (just mentioned), the retinacula also thickens anteriorly to form two structures:
```
Palmar carpal ligament
Flexor retinaculum (also called the transverse carpal ligament)
```
66
Both of these structures are continuous with the antebrachial fascia
```
Palmar carpal ligament
Flexor retinaculum (also called the transverse carpal ligament)
```
Slide 90, 91 92
67
The tendon of the palmaris longus muscle, ulnar nerve, and ulnar artery lie between the palmar carpal ligament and
flexor retinaculum
68
The canal formed by the ____ and the carpal bones transmits the tendons of the flexor pollicis longus, flexor digitorum superficialis, and flexor digitorum profundus muscles.
flexor retinaculum
slide 93
The carpal tunnel also contains the median nerve.
69
results from any lesion that significantly reduces the size of the carpal tunnel
carpal tunnel syndrome
70
carpal tunnel syndrome can be caused by
Fluid retention
Infection
Excessive exercise of the fingers
71
the most sensitive structure in the carpal tunnel, and is therefore most affected
median nerve
72
Median nerve has two terminal sensory branches that supply the skin of the hand in the
lateral three and one-half digits (thumb and fingers in the middle)
73
Hypoesthesia (diminished sensation) or anesthesia (loss of sensation) may occur in those areas supplied.
lateral three and one-half digits (thumb and fingers in the middle)
74
the ____ branch of the median nerve arises proximal to the carpal tunnel and does not pass through it, so sensation in the central palm remains unaffected.
(in carpal tunnel syndrome)
palmar cutaneous
75
The medial one and one-half digits will also be unaffected, since cutaneous sensation to them is provided by the ___.
(in carpal tunnel syndrome)
ulnar nerve.
76
Carpal tunnel syndrome can also result in progressive loss of coordination and strength in the thumb if the cause of the median nerve compression is not alleviated, as the ___branch of the median nerve is a terminal motor branch serving three___muscles
thenar
Persons with median nerve compression are unable to oppose the thumb
77
a way to detect irritated nerves
Tinel’s sign
78
performed by lightly tapping (percussing) over the nerve to elicit a sensation of paraesthesia (pins and needles feeling) that follows the distribution of the nerve
Tinel’s sign
79
In carpal tunnel syndrome where the ____ is compressed at the wrist, Tinel’s sign is often positive, causing tingling in the thumb, index finger, and middle finger
median nerve
80
Tinel’s sign is often referred to as ____
“distal tingling on percussion” or DTP
81
Slide 1 hunnit
check it
82
The ___ is an extension of the tendon of the palmaris longus muscle.
palmar aponeurosis
83
The ____ is the most superficial structure of the hand. Some of its fibers attach to the overlying skin at the palm creases, and other fibers go deep to attach to the fascia, metacarpals, and phalanges.
palmar aponeurosis
84
```
Thenar muscles
Hypothenar muscles
Adductor muscle
Lumbrical muscles
Interosseus muscles
```
Intrinsic muscles of the hand
85
Muscles of the thenar compartment are the . . .
Abductor pollicis brevis
Flexor pollicis brevis
Opponens pollicis
86
They move the thumb ....
Abductor pollicis brevis
Flexor pollicis brevis
Opponens pollicis
87
Together they produce the thenar eminence on the lateral surface of the palm
Abductor pollicis brevis
Flexor pollicis brevis
Opponens pollicis
88
The motor branch of the ___ nerve distributes to muscles of the thenar compartment
median
89
Thumb movements on slide 103
Thumbs up buddy and check 104
90
Origin: flexor retinaculum, scaphoid, and trapezium
Insertion: lateral side of proximal phalanx of thumb
Action: abducts thumb (and helps oppose it)
Innervation: median nerve
Abductor Pollicis Brevis
91
Abductor Pollicis Brevis
Origin: flexor retinaculum, scaphoid, and trapezium
Insertion: lateral side of proximal phalanx of thumb
Action: abducts thumb (and helps oppose it)
Innervation: median nerve
92
Origin: flexor retinaculum, scaphoid, and trapezium
Insertion: lateral 1st metacarpal
Action: draws 1st metacarpal medially to oppose little finger toward center of palm
Innervation: median nerve
Opponens Pollicis
93
Opponens Pollicis
scaphoid, and trapezium
Insertion: lateral 1st metacarpal
Action: draws 1st metacarpal medially to oppose little finger toward center of palm
Innervation: median nerve
94
Origin: flexor retinaculum, scaphoid, and trapezium
Insertion: lateral side of proximal phalanx of thumb
Action: flexes thumb
Innervation: median and ulnar nerves
Flexor Pollicis Brevis
95
Flexor Pollicis Brevis
Origin: flexor retinaculum, scaphoid, and trapezium
Insertion: lateral side of proximal phalanx of thumb
Action: flexes thumb
Innervation: median and ulnar nerves
96
Origin: anterior (palmar side) of 2nd and 3rd metacarpals
Insertion: medial side of proximal phalanx of thumb
Action: draws 1st metacarpal medially toward center of palm (adducts thumb)
Innervation: ulnar nerve
Adductor Pollicis
97
Adductor Pollicis
Origin: anterior (palmar side) of 2nd and 3rd metacarpals
Insertion: medial side of proximal phalanx of thumb
Action: draws 1st metacarpal medially toward center of palm (adducts thumb)
Innervation: ulnar nerve
98
NOTE: This is a muscle of the adductor compartment, not a muscle of the thenar compartment!!!
Adductor Pollicis
99
The adductor of the thumb is the deeply placed, fan-shaped ___. It adducts the thumb—moves the thumb to the palm of the hand—giving power to the grip. It is located in the adductor compartment of the hand (not the thenar compartment).
adductor pollicis
100
Name comes from hyperabduction of the MP joint when the thumb is held by the ski pole while the rest of the hand hits the ground or enters the snow. Also present in other athletic endeavors, especially football, baseball, and bull riding. In general, this occurs when a person extends the arm in an attempt to block a fall. In severe injuries the head of the metacarpal has an avulsion fracture.
Skier’s thumb/Gamekeeper’s thumb
Slide 111
Gamekeepers develop this injury from carrying game home in a bag draped over the shoulder, the thong of which is held by the thumb.
101
The chief difference is that skier’s thumb is generally an acute condition after a fall, whereas ____ is a chronic condition that develops over time
gamekeeper’s thumb
102
Abductor digiti minimi
Flexor digiti minimi brevis
Opponens digiti minimi
Muscles of the hypothenar compartment
103
They move the little finger
Abductor digiti minimi
Flexor digiti minimi brevis
Opponens digiti minimi
104
Together they produce the hypothenar eminence on the medial side of the palm
Abductor digiti minimi
Flexor digiti minimi brevis
Opponens digiti minimi
105
Muscles of the hypothenar compartment are all innervated by the ulnar nerve
Abductor digiti minimi
Flexor digiti minimi brevis
Opponens digiti minimi
106
The hypothenar compartment contains three muscles that correspond to muscles in the thenar compartment, but which have actions on the ____instead of the thumb.
little finger
107
Origin: pisiform
Insertion: medial side of proximal phalanx of little finger
Action: Abducts and flexes little (5th) finger
Innervation: ulnar nerve
Abductor Digiti Minimi
108
Abductor Digiti Minimi
Origin: pisiform
Insertion: medial side of proximal phalanx of little finger
Action: Abducts and flexes little (5th) finger
Innervation: ulnar nerve
109
Origin: flexor retinaculum and hamate (hook of hamate)
Insertion: medial side of proximal phalanx of little finger
Action: flexes little (5th) finger
Innervation: ulnar nerve
Flexor Digiti Minimi Brevis
110
Flexor Digiti Minimi Brevis
Origin: flexor retinaculum and hamate (hook of hamate)
Insertion: medial side of proximal phalanx of little finger
Action: flexes little (5th) finger
111
Origin: flexor retinaculum and hamate (hook of hamate)
Insertion: medial 5th metacarpal
Action: draws 5th metacarpal anteriorly, bringing little finger (5th digit) into opposition with thumb
Innervation: ulnar nerve
Opponens Digiti Minimi
112
Opponens Digiti Minimi
Origin: flexor retinaculum and hamate (hook of hamate)
Insertion: medial 5th metacarpal
Action: draws 5th metacarpal anteriorly, bringing little finger (5th digit) into opposition with thumb
Innervation: ulnar nerve
113
The ___muscles are named for their wormlike appearance
lumbrical
114
Rather than attaching to bone, the lumbricals attach proximally to tendons of the _____ and distally to parts of the extensor digitorum tendon called extensor expansions
flexor digitorum profundus,
115
They flex the digits at the metacarpophalangeal joints and extend the interphalangeal joints
lumbrical muscles
116
The two lateral lumbrical muscles are innervated by the median nerve; the two medial muscles by the deep branch of the ____
ulnar nerve
117
Origin: distal portion of flexor digitorum profundus tendons
Insertion: distal portion of extensor digitorum tendons
Action: flexes and extends fingers
Innervation: median and ulnar nerves
Lumbricals
118
Lumbricals
Origin: distal portion of flexor digitorum profundus tendons
Insertion: distal portion of extensor digitorum tendons
Action: flexes and extends fingers
Innervation: median and ulnar nerves
119
Slide 119
Scary
120
Interosseous muscles are located between the
metacarpals
121
#? dorsal interosseous muscles
#? palmar interosseous muscles
Four
Three
122
The four dorsal interossei ____the digits
abduct
123
The three palmar interossei ____ them
adduct
124
Interosseous muscles are innervated by the deep branch of the
ulnar nerve
125
Origin: palmar surfaces of metacarpals
Insertion: digits 2, 4 and 5
Action: adducts and flexes fingers (acting with lumbricals)
Innervation: ulnar nerve
Palmar Interossei
126
es of metacarpals
Insertion: digits 2, 4 and 5
Action: adducts and flexes fingers (acting with lumbricals)
Origin: palmar surfaces of metacarpals
Insertion: digits 2, 4 and 5
Action: adducts and flexes fingers (acting with lumbricals)
Innervation: ulnar nerve
127
Origin: adjacent sides of two metacarpals (bipennate muscles)
Insertion: digits 2, 3, 4
Action: abduct digits; extend fingers (acting with lumbricals)
Innervation: ulnar nerve
Dorsal Interossei
128
Dorsal Interossei
Origin: adjacent sides of two metacarpals (bipennate muscles)
Insertion: digits 2, 3, 4
Action: abduct digits; extend fingers (acting with lumbricals)
Innervation: ulnar nerve
129
The anatomical snuff box is formed by tendons of the
abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus
130
In the Anatomical snuff box, The radial artery lies in its floor
The ____ and base of the first metacarpal can be palpated in it
The scaphoid and trapezium can be felt in its floor
radial styloid process
131
The superficial branch of the ___ nerve provides cutaneous innervation to the anatomical snuff box and surrounding area
radial
132
___ fractures often occur with a fall onto the palm or fall on an outstretched hand (FOOSH). Fractures of the ___ usually cause pain and sensitivity to palpation in the anatomic snuffbox. Pain is worsened by gripping or squeezing
Scaphoid
133
The blood supply to the hand is furnished by branches of the ulnar and radial arteries
The ulnar artery divides near the ____ into superficial and deep branches
The superficial branch continues into the palm to give rise to the superficial palmar arch. The remainder of the arch is formed by the superficial branch of the radial artery.
wrist
134
Intrinsic hand muscles innervated by the ___ nerve are the: abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi (which are all of the hypothenar compartment muscles), adductor pollicis, and in conjunction with the median nerve, the flexor pollicis brevis and lumbricals
ulnar
slide 129
135
____ muscles innervated by the median nerve are the: abductor pollicis brevis, opponens pollicis, and flexor pollicis brevis (which are all of the thenar muscles (fpb is also innervated by the ulnar nerve))
Thenar
136
The hand is normally supplied with blood from the ulnar and radial arteries, which undergo ___ in the hand. If the blood supply from one of the arteries is cut off, the other artery can supply adequate blood to the hand
anastomosis
137
Patency of the radial and ulnar arteries, and the collateral circulation of the hand, is assessed by the
Allen test (Allen’s test)
138
___ is commonly used to reduce the risk of ischemia by ensuring the patency of the radial and ulnar arteries prior to radial arterial blood sampling or cannulation
Allen’s test
139
Patient rests the hand, palm up, and makes a fist for about 30 seconds, either with or without first opening and closing the hand a few times
Pressure is applied over the ulnar and radial arteries so as to occlude both
The hand is opened
Ulnar pressure is released
The general conduct of Allen's test is as follows, although exact details can vary
140
Allens test: Return of color within __ seconds indicates a patent ulnar artery, meaning it is safe to use the radial artery for ABGs or cannulation
7
Slide 134
141
A small proportion of people do not have the dual blood supply of both radial and ulnar arteries. Since the condition is generally not bilateral, the other side may usually be used following performance of the
Allen test on that side
142
Slide 136-142 for
cutaneous innervation
If you have ideas on how to capture this in card form, I'm all ears...
143
____ is essentially a function of the median nerve; ____ is a function of the musculocutaneous and radial nerves
Pronation is essentially a function of the median nerve; supination is a function of the musculocutaneous and radial nerves
144
Pronation is essentially a function of the
median nerve
145
supination is a function of the __ and ___ nerves
musculocutaneous and radial nerves
146
At the radial artery can be compressed against the radius where it lies between the tendons of the __ and __
flexor carpi radialis and abductor pollicis longus
147
The flexor retinaculum stretches across the wrist from the scaphoid and trapezium bones on the radial side to the...
hamate and pisiform bones on the ulnar side.
148
The tendon of the palmaris longus muscle, ulnar nerve, and ulnar artery lie between the ___ and ____
palmar carpal ligament and flexor retinaculum
149
In the Y-shaped split in the ligament is the tendon of the
flexor carpi radialis.
150
The canal formed by the flexor retinaculum and the carpal bones transmits the tendons of the
flexor pollicis longus, flexor digitorum superficialis, and flexor digitorum profundus muscles.
151
hyperabduction of the MP joint
Skier’s thumb/Gamekeeper’s thumb
152
Skier’s thumb/Gamekeeper’s thumb
This is a rupture or chronic laxity of the ______ of the thumb
ulnar collateral ligament (UCL)
