Lippert: Chapter 13 Hand

Functional position of the hand

Wrist is slightly extended, MCP and PIP joints of the fingers are slightly flexed, and the thumb is in opposition

extensor retinaculum

a fibrous band traversing the posterior side of the wrist in a horizontal mediolateral direction; attaches medially to the styloid process of the ulna and to the triquitrum, pisiform and lateral side of the radius

Accessory movement

a movement that accompanies the active movement and is essential to normal -rotation at the CMC joint of the thumb is passive, not voluntary, motion which occurs as a result of the joint's shape (saddle joint)

Name the posterior extrinsic muscles of the thumb and fingers

abductor pollicis longus extensor pollicis brevis extensor pollicis longus extensor digitorum extensor indicis extensor digiti minimi

pad-to-side grip

aka lateral prehension, has the pad of the extended thumb pressins an object against the radial side of the index finger. This is a strong grip, but it allows less fine movements. The terminal device of upper extremity protheses adapts this type of grip. Because this grip does not require an opposed thumb, a person who has lost opposition but has retained thumb adduction can grasp and hold small objects ( adductor pollicis is innervated by ulnar nerve)

lumbrical grip

aka plate grip, the MCP flexed and the PIP and DIP joints extended. The thumb opposes the fingers holding an object horizontal. It is called a lumbrical grip because the action of the lumbrical muscles is to flex the MCP while extending the IP joints

Precision grip

aka precision prehension, is used when an object must be manipulated in a finer type movement, such as holding a pen or threading a needle

stenosing tenosynovitis

aka trigger finger; is a problem w/ sliding mechanism of a tendon in its sheath; when nodule or swelling of the sheath lining or the tendon; may pass into sheath w/ fingers flexed and stuck when finger extends

spherical grip, name some examples

all fingers and thumb abducted around an object, and, unlike the cylindrical grip, the fingers are spread apart. Palm of hand often not involved. EX holding an apple or a doorknob or picking up a glass by its top

longitudinal arch

begins at the wrist and runs the length of the metacarpal and phalanges for each digit. It is perpendicular to the other two arches

ganglion cyst

benign tumor mass commonly seen as a bump on the dorsal surface of wrist

The MCP of the fingers are ___axial __________ joints.

biaxial condyloid. The convex, rounded heads of the metacarpals articulate with the base of the proximal phalanges, which have a concave shape. These are commonly referred to as the "knuckles."

Which finger and thumb motions occur in b. the sagittal plane around the front axis?

b. Finger: MCP, PIP, DIP flexion/extension Thumb: CMC abduction/adduction

Which finger and thumb motions occur in c. the transverse plane around the vertical axis?

c. Thumb: CMC opposition/reposition

skier's thumb

common hand injury among athletes, involves acute tear of ulnar collateral ligament of thumb

carpal tunnel syndrome

compression of median nerve w/in carpal tunnel

Name the power grips

cylindrical (cylindrical grip variation), spherical, hook grip

Explain the difference between the thenar muscles and hypothenar muscles, and give an example of each.

Thenar muscles are intrinsic muscles on the thumb side (lateral) of the hand Hypothenar muscles are on the little finger side (medial). Any intrinsic muscle with pollicis in its name is a thenar muscle, whereas one with digiti minimi is a hypothenar muscle.

What hand muscle does not have a bony attachment? To what two tendons does it attach?

The lumbricales; they attach proximally to the tendons of the flexor digitorum profundus muscles and distally to the tendons of the extensor digitorum muscle.

scaphoid fracture

fall on outstretch hand of younger person and b/c of poor vascular supply has high incidence of avascuular necrosis

The CMC joint of the thumb is usually considered______ joint. Name the joint motions.

"modified" biaxial joint -flexion/extension -abduction/adduction -opposition ("built-in" accessory motion of rotaiton)/reposition

The thumb has how many joints? Name them.

3; CMC, MCP, IP

How many joints does the second, third, fourth, and fifth digits have? Name them.

4; CMC, MCP, PIP, DIP

What is an extrinsic muscle? List the extrinsic muscles of the hand.

An extrinsic muscle has its proximal attachment above the wrist and its distal attachment below the wrist. The extrinsic muscles include the flexor digitorum superficialis and profunduc, extensor digitorum, extensor digiti minimi, and extensor indicis muscles of the fingers. Extrinsic muscles of the thumb are the flexor pollicis longus, abductor pollicis longus, and extensor pollicis longus and brevis.

What is an intrinsic muscle? List the intrinsic muscles of the hand.

An intrinsic muscle has both attachments below the wrist; the nine intrinsic muscles include flexor and abductor pollicis brevis, the opponens and adductor pollicis, the flexor/abductor/opponens digiti minimi, the interossei, and the lumbricales.

opponens pollicis Origin: Insertion: Action: Nerve:

Origin:trapezium and flexor retinaculum Insertion: first metacarpal Action: opposes thumb (CMC joint) Nerve: median nerve (C6, C7)

Thumb opposition is a combination of what motions?

CMC flexion, abduction, and rotation

What is the shape of the proximal end of the proximal phalange of the fingers?

Concave

What is the shape of the distal end of the finger metacarpals?

Convex

The deep palm muscles have what function? Name them.

Located deep in the hand between thenar and hypothenar muscles and perform more intricate motions that usually involved multiple muscles adductor pollicis interossei lumbricales

The thenar muscles have what function? Name them.

Function to move the thumb, thenar eminence (AFO) abductor pollicis brevis flexor pollicis brevis opponens pollis

What is the purpose of the retinaculum?

It holds the extrinsic tendons close to the wrist.

palmar interossei Origin: Insertion: Action: Nerve:

Origin: 1st, 2nd, 4th, and 5th metacarpals Insertion: base of respective proximal phalanx Action: adducts fingerst at MCP joint Nerve: ulnar nerve (C8, T1)

Flexor pollicis brevis Origin: Insertion: Action: Nerve:

Origin: Trapezium and flexor retinaculum Insertion: proximal phalanx of the thumb Action: flexes the CMC and MCP of thumb Nerve: median nerve (C6, C7)

dorsal interossei Origin: Insertion: Action: Nerve:

Origin: adjacent metacarpals Insertion: base of proximal phalanx Action: abduct fingers at MCP joint Nerve: ulnar nerve (C8, T1)

adductor pollicis Origin: Insertion: Action: Nerve:

Origin: capitate, base of the 2nd metacarpal, palmar surface of the 3rd metacarpal Insertion:base of proximal phalanx of thumb Action:adducts thumb (CMC joint) Nerve: ulnar nerve (C8, T1)

flexor digitorum superficialis Origin: Insertion: Action: Nerve:

Origin: common flexor tendon on the medial epicondyle, coronoid process, and radius Insertion: sides of the middle phalanx of the four fingers Action: flexes the MCP and PIP joints of the fingers Nerve: Median nerve (C7, C8, T1)

extensor indicis Origin: Insertion: Action: Nerve:

Origin: distal ulna Insertion: base of distal phalanx of the second "index" finger Action: extends MCP, PIP and DIP Nerve: radial nerve (C6, C7, C8)

opponens digiti minimi Origin: Insertion: Action: Nerve:

Origin: hamate and flexor retinaculum Insertion: 5th metacarpal Action: opposes the 5th finger (CMC joint) Nerve: ulnar nerve (C8, T1)

flexor digiti minimi Origin: Insertion: Action: Nerve:

Origin: hamate and flexor retinaculum Insertion: base proximal phalanx of 5th finger Action: flexes CMC and MCP joints of 5th finger Nerve: ulnar nerve (C8, T1)

extensor digiti minimi Origin: Insertion: Action: Nerve:

Origin: lateral epicondyle of humerus Insertion: base of distal phalanx of fifth finger Action: extends MCP, PIP and DIP Nerve: radial nerve (C6, C7, C8)

extensor digitorum Origin: Insertion: Action: Nerve:

Origin: lateral epicondyle of the humerus Insertion: base of distal phalanx of the second through fifth fingers Action: extends all three joints of the fingers (MCP, PIP, and DIP) Nerve: Radial nerve (C6, C7, C8)

extensor pollicis longus Origin: Insertion: Action: Nerve:

Origin: middle posterior ulna and interosseous membrane Insertion: base of the proximal phalanx of thumb Action: extends CMC and MCP joints of thumb Nerve: radial nerve (C6, C7)

abductor digiti minimi Origin: Insertion: Action: Nerve:

Origin: pisiform and tendon of flexor carpi ulnaris Insertion: proximal phalanx of 5th finger Action: abducts MCP joint of 5th finger Nerve: ulnar nerve (C8, T1)

extensor pollicis brevis Origin: Insertion: Action: Nerve:

Origin: posterior distal radius Insertion: base of the proximal phalanx of thumb Action: extends CMC and MCP joints of thumb Nerve: radial nerve (C6, C7)

abductor pollicis longus Origin: Insertion: Action: Nerve:

Origin: posterior radius, interosseous membrane, middle ulna Insertion: base of the first metacarpal Action: abducts thumb (CMC) Nerve: radial nerve (C6, C7)

flexor pollicis longus Origin: Insertion: Action: Nerve:

Origin: radius, anterior surface Insertion: distal phalanx of thumb Action: flexes CMC, MCP, IP of thumb Nerve: median nerve (C8, T1)

abductor pollicis brevis Origin: Insertion: Action: Nerve:

Origin: scaphoid, trapezium, and flexor retinaculum Insertion: proximal phalanx of thumb Action: abducts the thumb (CMC joint) Nerve: median nerve (C6, C7)

lumbricales Origin: Insertion: Action: Nerve:

Origin: tendon of the flexor digitorum profundus muscle Insertion: tendon of extensor digitorum muscle Action: flex MCP while extending PIP and DIP joints Nerve: 1st and 2nd lumbricales: median 3rd and 4th lumbricales: ulnar (C6, C7, C8)

flexor digitorum profundus Origin: Insertion: Action: Nerve:

Origin: upper three-fourths of the ulna Insertion: distal phalanx of the four fingers Action: flexes all three joints of the fingers (MCP, PIP, and DIP) Nerve: Median and ulnar nerves (C8, T1)

Name the two types of prehension

Power grips and precision grips

Is the joint surface of the proximal phalange moving in the same or opposite direction as the finger in MCP flexion/extension?

Same

What structures makeup the carpal tunnel? Which tendons and nerve run through the carpal tunnel?

The floor of the carpal tunnel is made up of the carpal bones, and the ceiling is the transverse carpal ligament portion of the flexor retinaculum. The flexor digitorum superficialis and profundus and the flexor pollicis longus muscles and the median nerve run through the carpal tunnel.

What is the "anatomical snuffbox"? Which muscles act as the borders of this area?

The indentation formed between the tendons of the abductor pollicis longus and extensor pollicis brevis laterally and extensor pollicis longus medially is referred to as the anatomical snuffbox.

Which finger and thumb motions occur in a. the front plane around the sagittal axis?

a. Finger: MCP abduction/adduction Thumb: CMC flexion/extension, MCP and IP flexion/extension

transverse carpal ligament

deeper and more distal; attaches to the pisiform and hook of hamate on the medial side and to the scaphoid and trapezium bones laterally.

mallet finger

disruption of the extensor mechanism of the DIP joint, either b/c tendon was severed or b/c the portion of bone where the tendon attached has avulsed from the distal phalanx; the distal phalanx remains flexed and cannont extend.

boutonniere deformity

extension of MCP, flexion of PIP, and extension of DIP

Cylindrical grip variation, Name some examples

fingers flexed around a handle in a graded fashion. The fifth finger joints are flexed the most, and the second fingers joints are only partly flexed. The thumb lies parallel and against the handle, and the wrist is in slight ulnar deviation. The advantage of this grip over a cylindrical grip is that it allows a foreceful but more controlled use of the tool. EX holding a golf club or screwdriver

The trapezium articulates with the base of the ____ metacarpal.

first

swan neck deformity

flexion of MCP joint, (hyper) extension of PIP joint, and flexiong of DIP joint

The motions allowed at the MCP joints are

flexion, extension, and hyperextension, plus abduction and adduction

Name the anterior extrinsic muscles of the thumb and fingers

flexor digitorum superficialis flexor digitorum profundus flexor pollicis longus

Hypothenar muscles? Name them.

form hypothenar eminence, act on little finger (AFO) abductor digiti minimi flexor digiti minimi opponens digiti minimi

proximal carpal arch

formed by the proximal end of the metacarpals (base) and carpal bones and is maintained by the flexor retinaculum

The hamate with the ___ and ___ metacarpals.

fourth and fifth

Cylindrical grip, name some examples

has all the fingers flexed around the object, which usually lies at a right angle to the forearm. The thumb is wrapped around the object in the opposite direction, often overlapping the fingers. EX. holding a hammer, a racquet, or a wheelbarrow handle

Intrinsic muscles

have their proximal attachment at, or distal to, the carpal bones and have a function on the thumb or fingers. Fine motor control and precision movement.

"greenstick" fracture

incomplete fracture, usually of the radius and more proximal than a Colles' fracture; more common in children

DeQuervain's disease

inflammation and thickening of the sheath containing the extensor pollicis brevis and abductor pollicis longus, resulting in pain on radian side of wrist (tenosynovitis-inflammation of tendons and their surrounding sheaths)

tip-to-tip grip

involves bringing the tip of the thumb up against the tip of another digit, usually the index finger, to pick up a small object such as a coin or a pin. AKA pincer grip

hook grip, name some examples

involves the 2nd-5th fingers flexed around an object in a hooklike manner. MCP joints are extended, and the PIP and DIP joints are in some degree in flexion. The thumb is usually not involved. Therefore, this is the only power grip possible if a person has a median nerve injury and loses the ability to oppose the thumb. EX holding on to a handle, such as a suitcase, a wagon, or a bucket

palmar carpal ligament

more proximal and superficial; attaches to styloid processes of the radius and ulna and crosses over the flexor muscles

extrinsic muscles

muscles of the hand where the proximal attachment is above, or proximal to, the wrist joint

Kienbock's disease

necrosis of lunate which may develop after trauma

Carpometacarpal joints of the fingers are classified as ____axial ___ ___ ____.

nonaxial plane (irregular) synovial joints that provide more stability than mobility

Dupuytren's contracture

occurs when palmar aponeurosis undergoes a nodular thickening; most commong in the palm area in line w/ ring and little fingers.

three-jaw chuck, name an example

pad-to-pad variation involving the thumb and two fingers, EX holding a pen or pencile

Name the precision grips

pad-to-pad, pinch, three-jaw chuck, tip-to-tip, pincer, pad-to-side, side-to-side, lumbrical(plate) grip

The flexor retinaculum consists of what two parts?

palmar carpal ligament and transverse carpal ligament

Which of the thumb opposition motions is an accessory motion?

rotation

What is the most frequently injured carpal bone?

scaphoid

The trapezoid articulates with the ___ metacarpal.

second

distal carpal

shallower and made up of the metacarpal heads

extensor expansion ligament

small, triangular, flat aponeurosis covering the dorsum and sides of the proximal phalanx of the fingers; the extensor hood area is formed by the extensor expansion proximally, covers the head of the metacarpal and keeps the extensor tendon in the midline

side-to-side grip

somewhat similar to pad-to-side grip, requires adduction of two fingers, usually the index or middle fingers. It is a weak grip and does not permit much precision. It is perhaps most frequently used to hold a cigarette. It is also used to hold an object, like a pencil, between two fingers while using another pencil or pen. Because the thumb is not involved, this grip could be used in the absence of the thumb. (palmar interossei - ulnar nerve C8, T1)

gamekeeper's thumb

stretching injury developed over time by English gamekeepers at they twisted the necks of small game

pad-to-pad grip

the MCP and PIP joints of the finger(s) are flexed, the thumb is abducted and opposed, and the distal joints of both are extended, bringing the pads of the finger(s) and thumb together. When it involves the thumb and one finger, usually the index finger, it is called a pinch grip

Smith's fracture

the distal fragment is displaced anteriorly (reverse Colles') and is cased by a fall on the back of the hand

The capitate with the ___ metacarpal.

third metacarpal

What's the most common precision grip?

three-jaw chuck

Compare the thumb and fingers: a. Number of bones Thumb___ Finger___

thumb - 4 finger - 5

Compare the thumb and fingers: b. Number of joints Thumb___ Finger___

thumb-3 finger-4

Compare the thumb and fingers: b. Names of joints Thumb___ Finger___

thumb-cmc, mcp, ip finger- cmc, mcp, pip, dip

Colles' fracture

transverse fracture of the distal radius includes posterior displacement of the distal fragment

ulnar drift

ulnar deviation of fingers at MCP joint

PIP and DIP joints are ___axial ______ joints.

uniaxial hinge joints and allow only flexion and extension.

Power grip

used when an object must be held forcefully while being moved about by more proximal joint muscles (holding a hammer or doorknob); Often a power grip involves an isometric contraction with no movement occurring b/w the hand and the object being held