PHM Exam 4

Which annular ligament is most commonly involved in trigger finger?

A1

Which annular ligaments overlie the MP, PIP and DIP joints respectively?

A1 A3 A5

Which annular ligaments are critical to prevent bowstringing?

A2 A4

In a precision grasp, the active muscles ___________ or _____________ the thumb; the hand's position is ______________.

Abduct, oppose; dynamic

The lateral axis of the thumb causes which actions?

Abduction/Adduction

What structure represents a convenient place to palpate the scaphoid bone and capitate bone: a nice landmark for the medically located true axis of the wrist?

Anatomical snuffbox

____________ glide occurs with IP flexion.

Anterior

_______________ glide occurs with MP flexion

Anterior

Therapeutic splints must support the three ____________, otherwise mobility isn't he hand is lost.

Arches

How do the lumbricles cause PIP and DIP extension?

By introducing tension into the extensor expansion.

List the 3 cruciate pulleys.

C1 C2 C3

What two structures support the MP joint capsule and adds stability to the fingers?

Collateral ligaments (radial & ulnar)

____________ _____________ function to prevent sheath collapse and expansion during digital motion.

Cruciate pulleys

Tension in the lateral bands extend the ________________ joints.

DIP

What nerve innervates the anatomical snuffbox muscles?

Deep interosseus branch of radial nerve

Which arch causes a combination of "radial" stability and "ulnar" mobility?

Distal transverse arch

The lumbricles and interossei attach into the extensor expansion via the oblique and transverse fibers of the __________ ___________.

Dorsal hood

The specialized band of tissue with transverse and oblique fibers that run perpendicular to the long axis of the EDC is called...

Dorsal hood

Which interossei muscles have attachments on the middle finger?

Dorsal interossei

The extensor expansion develops passive tension whenever it is ____________.

Elongated

When the hand is in the functional position, should the wrist be flexed or extended?

Extended (20 degrees)

Thumb reposition is a combination of CMC ___________ and _________________.

Extension, adduction

Since the abductor pollicis longus also produces radial deviation of the wrist, which muscle must also act to prevent wrist motion?

Extensor carpi ulnaris

Which two muscles are structurally similar to the extensor digitorum communis?

Extensor indicis Extensor digiti minimi

List the muscles that insert into the extensor expansion.

Extensor indicis Extensor digiti minimi Lumbricles Palmer interossei Dorsal interossei

What muscle is the *only* muscle to extend the IP joint of the thumb directly, not through extensor expansion attachment?

Extensor pollicis longus

True/False: Most resistance to the hand is due to gravity.

False

True/False: Tension in the extensor digitorum communis tendon is strong enough to extend the PIP joint.

False

True/False: The fingers are relatively stable.

False

True/False: We can extend the PIP joint without extending the DIP joint at the same time.

False

True/False: You can passively rotate the CMC joint when you place it in full opposition or reposition.

False

The hand is more likely to __________.

Flex

What actions are available at the CMC joints of the fingers?

Flexion and extension

Thumb opposition is a combination of CMC ____________ and ___________

Flexion, abduction

Acting alone, the lumbricles produce MP _________, PIP and DIP ___________.

Flexion, extension

What actions are available at the DIP joints?

Flexion, extension

What actions are available at the PIP joints?

Flexion, extension

The AP axis of the thumb causes which actions?

Flexion/Extension

Which metacarpals are more mobile?

Fourth and fifth

The oblique fibers of the dorsal hood course distally and dorsally to fuse with the ___________ __________.

Lateral bands

What are the actions of the palmar interossei muscles?

MP adduction MP flexion (in certain instances) PIP extension DIP extension

What nerve innervates the coracobrachialis, biceps brachii and greater part of the brachialis?

Musculocutaneous nerve

What ligament(s) coordinate movement between the PIP and DIP joints?

Oblique retinacular ligaments

The _____________ actions of the EDC and the intrinsic muscles across the MP joint allow them to extend the IP joints.

Opposing

If tension is placed into the central band, it extends the _________ joint.

PIP

List the types of precision grasps

Palmar prehension Tip-to-tip Lateral prehension (with thumb abducted)

_______________ glide occurs with MP extension

Posterior

What is the direct effect of the interossei on hand opening?

Proximal pull on the extensor expansion causes the PIP and DIP joints to extend.

At the PIP and DIP joints of digits 2-5, roll and glide occur in the ____________ direction.

Same

Which finger will be able to abduct the greatest?

Second digit. This is because most of the DI muscle fibers attach here.

The arches provide a balance between ________________ and ____________ for grasping.

Stability, mobility

What is responsible for the partially flexed posture of a relaxed hand?

The passive "recoil" force generated within the finger flexors.

What is the indirect effect of the interossei on hand opening?

The production of a flexion torque at the MP joint. This prevents the extensor digitorum from *hyperextending* at the MP joint.

What causes resistance to the hand?

The tautness of the long finger flexors

True/False: Although the CMC has a loose capsule that permits rotation, it is still a biracial joint.

True

True/False: Flexing the DIP joint without also flexing the PIP joint is difficult.

True

True/False: The central band is made of non contractile tissue.

True

True/False: Thumb extension is possible even if one of the peripheral nerves is injured.

True

True/False: We can extend the PIP and DIP joints without also extending the MP joints.

True

A lesion to which nerve would decrease pinching force by almost 80%?

Ulnar nerve

Diabetes and chemotherapy induced neuropathy can cause complications to which nerve?

Ulnar nerve

If a patient cannot hold paper between extended but adducted fingers (intrinsic muscles of the hand), there may be damage at which nerve?

Ulnar nerve

If trams has occurred to the elbow region, which nerve will most likely be effected?

Ulnar nerve

Wasting of web space and interosseus spaces can be effects of damage to which nerve?

Ulnar nerve

What structure enlarges the proximal phalanx' relatively small articular surface?

Volar plate

A lack of wrist extension may cause hand grip to be __________.

Weak

The _________ ___________ maintain the optimal length of the EDC during active finger extension.

Wrist flexors

What offsets the large extension moment of the EDL at the wrist, thus allowing MP extension instead?

Wrist flexors

When utilizing a "key pinch" grasp, which muscle is activated to counteract the flexor force of the flexor pollicis longus?

1st dorsal interosseus

List the intrinsic (thenar) muscles of the thumb

Abductor pollicis brevis Adductor pollicis First dorsal interosseus Flexor pollicis brevis Opponens pollicis

Which muscles have fibers on the first digit's extensor expansion?

Abductor pollicis brevis Adductor pollicis Ulnar head of flexor pollicis brevis First palmar interosseus Extensor pollicis longus

What muscles make up the thenar eminence?

Abductor pollicis brevis Flexor pollicis brevis Opponens pollicis

The ____________ _______________ ____________ acts in synchrony with any action of the thenar muscles.

Abductor pollicis longus

What muscle is the prime abductor of the CMC joint?

Abductor pollicis longus

List the extrinsic muscles of the thumb.

Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Flexor pollicis longus

List the muscles of the anatomical snuff box.

Abductor pollicis longus Extensor pollicis. Brevis Extensor pollicis longus

During rapid flexion of the IP joint at the thumb, the ________________ ______________ _______________ activity counters the _____________ ____________ ___________ tendency to flex the CMC joint in the plane of the palm.

Abductor pollicis longus, flexor pollicis longus

Which muscle forms the "bulk" of the web space between 1st and 2nd metacarpals?

Adductor pollicis

Which thumb muscle has an oblique head and transverse head?

Adductor pollicis

In a power grasp the __________ _________ stabilizes an object against the palm; the hand's position is _____________.

Adductor pollicis, static

Which spinal nerve roots make up the radial nerve?

C5, C6, C7, C8, and T1

Which spinal roots make up the median nerve?

C6, C7, C8 and T1

What spinal roots make up the ulnar nerve?

C8 and T1

Which bone is the key of the proximal transverse arch?

Capitate

When the saddle-shaped trapezium is in the plane of CMC abduction/adduction it is _____________.

Concave

When the saddle-shaped trapezium is in the plane of CMC flexion/extension, it is __________.

Convex

At the MP joints of digits 2-5, the proximal joint surface is __________ and the distal surface is ___________.

Convex, concave

List the types of power grasps.

Cylindrical grasp Spherical grasp Hook grasp Lateral prehension (if thumb is adducted

Passive flexion of the MP joint _____________ the extensor expansion and ___________ the PIP and DIP joints.

Elongates, extends

What are the actions of the extensor digitorum communis tendon?

Extends the MP joints, extends the wrist

Full (active or passive) flexion of the PIP joint prevents active ____________ of the DIP joint.

Extension

The lumbricles and interossei assist the EDC with ____________ of the PIP and DIP joints via the extensor expansion.

Extension

What is the closed-packed position of the IP joint of the thumb?

Extension

What is the closed-packed position of the MP joint of the thumb?

Extension

Where is the closed-packed position of the PIP and DIP joints?

Extension

List the extrinsic hand muscles that act on the second through fourth digits.

Extensor digitorum Extensor indicis Extensor digiti minimi Flexor digitorum superficialis Flexor digitorum profundus

List any muscles that extend the PIP joints of digits 2-5 as well as any non-contractile structures that allow extension

Extensor digitorum assists by creating tension in the central tendon Lumbricles via attachment to central tendon and lateral bands Palmar interossei via attachment to central tendon and lateral bands Dorsal interossei via attachment to central tendon and lateral bands

List the muscles that extend the MP joint of digits 2-5 as well as any non-contractile structures that allow extension.

Extensor digitorum communis

The extension expansion is a continuation of the __________ _____________ ______________ tendon.

Extensor digitorum communis

List the muscles that extend the wrist as well as any non-contractile structures that allow extension.

Extensor digitorum communis Extensor digiti minimi Extensor indicis Extensor carpi ulnaris Extensor carpi radialis longus Extensor carpi radialis brevis Extensor pollicis longus

List the thumb muscles needed to forcefully open the hand (mic drop)?

Extensor pollicis longus Extensor pollicis brevis Abductor pollicis longus Abductor pollicic brevis

Rapid extension of the thumbs IP joint involves the ____________ ____________ ___________ and is often accompanied by palpable activity in the _____________ _____________.

Extensor pollicis longus, thenar muscles

What is the closed-packed position of the CMC joint of the thumb?

Extremes of opposition or reposition

You cannot abduct or adduct the MP joints when they are ______________.

Flexed

Where is the closed-packed position of the CMC joint?

Flexion

Where is the closed-packed position of the MP joints of fingers 2-5?

Flexion

What actions are available at the MP joints of fingers 2-5?

Flexion, extension, abduction, adduction

Bowstringing can occur when the __________ _______________ ____________ tendon is no longer stabilized by the ____________ pulleys.

Flexor digitorum profundus

List the muscles that flex the DIP joint of digits 2-5 as well as any non-contractile structures that allow flexion.

Flexor digitorum profundus

Which finger flexor muscle attaches to the skeleton more distally?

Flexor digitorum profundus

List the muscles that flex the MP joint of digits 2-5 as well as any non-contractile structures that allow flexion.

Flexor digitorum profundus Flexor digitorum superficialis

List the muscles that flex the PIP joint of digits 2-5 as well as any non-contractile structures that allow flexion.

Flexor digitorum profundus Flexor digitorum superficialis

Which 2 muscles are most responsible for finger flexion?

Flexor digitorum profundus Flexor digitorum superficialis

List the muscles that flex the wrist as well as any non-contractile structures that allow flexion.

Flexor digitorum profundus Flexor digitorum superficialis Flexor carpi ulnaris Flexor carpi radialis Palmaris longus Flexor pollicis longus Extensor pollicis brevis Abductor pollicis longus

What muscles are innervated by the ulnar nerve?

Flexor digitorum profundus (digits 4 & 5) Opponens digiti minimi Flexor digiti minimi Lumbricles 3 & 4 Dorsal interossei Palmar interossei Adductor pollicis Abductor digiti minimi

Which thumb muscle has two heads: radial head and ulnar head?

Flexor pollicis brevis

In ulnar nerve injuries, the adductor pollicis and ulnar head of the flexor pollicis brevis will be affected. These individuals will be unable to grasp with these muscles and will instead use the __________ ____________ ____________ to flex the IP joint.

Flexor pollicis longus

List the extrinsic thumb muscles that act on the first digit.

Flexor pollicis longus Extensor pollicis longus Extensor pollicis brevis Abductor pollicis longus

List the thumb muscles needed to grip an object.

Flexor pollicis longus Flexor pollicis brevis Adductor pollicis Opponens pollicis Abductor pollicis longus to stabilize CMC joint Extensor carpi ulnaris and Flexor carpi ulnaris to prevent radial deviation from thumb muscles

Rapid flexion of the thumbs IP joint involves the ____________ _____________ ___________, and is often accompanied by the palpable activity in the _____________ ____________ _____________.

Flexor pollicis longus, abductor pollicis longus

Which finger will be able to abduct the *least*?

Fourth digit. This is because most of the fourth DI attaches to the extensor expansion itself.

Ulnar collateral ligament, radial collateral ligament, and smaller versions of volar plates support which joints?

IP joints

Lumbrical activity ___________ passive tension in the extensor expansion and _____________ passive tension in the FDP tenson's distal portion.

Increases, decreases

Before crossing the PIP, two __________ ___________ diverge from the central band.

Lateral bands

What is the only muscle in the body that does not have attachments on bone?

Lumbricles

What muscles transmit force to the otherwise non-contractile extensor expansion?

Lumbricles Palmar interossei Dorsal interossei

List the muscles that extend the DIP joints of digits 2-5 as well as any non-contractile structures that allow extension.

Lumbricles via attachment to lateral bands Palmar interossei via attachment to lateral bands Dorsal interossei via attachment to lateral bands

What are the actions of the dorsal interossei?

MP adduction MP flexion (in certain instances) PIP extension DIP extension

If a patient is experiencing a decrease in thumb function, particularly opposition which nerve is most likely effected?

Median nerve

If the thenar eminence has lost innervation, what nerve was most likely effected?

Median nerve

What nerve innervates the thenar eminence?

Median nerve

Which nerve passes through the carpal tunnel?

Median nerve

Activity in the ____________ _____________ counters the _____________ _______________ ___________'s tendency to extend the first MC joint or adduct it in a plane perpendicular to the palm.

Opponens pollicis, extensor pollicis longus

When the finger joints flex (MP, PIP, or DIP) it produces _________ __________ into the lateral bands & central slip which pull the extensor hood distally. The distal shift in the extensor hood _____________ the lumbricle's moment arm so then can produce a greater ____________ moment at the MP joint.

Passive tension

________________ glide occurs with IP extension.

Posterior

What muscles are innervated by the median nerve?

Pronator teres Palmaris longus Flexor carpi radialis Pronator quadratics Flexor digitorum superficialis Flexor digitorum profundus (lateral half) Lumbricles 1 & 2 Flexor pollicis longus Abductor pollicis brevis Opponens pollicis Flexor pollicis brevis

Which arch forms the posterior border of the carpal tunnel?

Proximal transverse arch

Which arch is located at the level of the caropometacarpal joint?

Proximal transverse arch

Which arch of the hand is rigid and maintained by activity in the hand's intrinsic muscles?

Proximal transverse arch

Which side (radial or ulnar) do the lumbricles attach at the level of the lateral bands?

Radial

Gunshot or stab wounds, fracture of the humerus, or "Saturday night palsy" often cause damage to which nerve?

Radial nerve

In general, the extensors of the upper extremity are innervated by which nerve?

Radial nerve

"Dropped wrist" and lack of ability to reposition the thumb are indications of...

Radial nerve palsy

What type of bone is the thumb?

Saddle joint

At the MP joints of digits 2-5, roll and glide occurs in the ____________ direction.

Same

Which muscles position the thumb for grasping?

Thenar eminnence

Where does the axis for thumb abduction and adduction pass?

Through the trapezium

Where does the axis for thumb flexion and extension pass?

Through the trapezium

Why is the wrist extended when utilizing the functional position of the hand?

To preserve the length-tension relationship at the wrist

What structure forms the anterior border of the carpal tunnel?

Transverse carpal ligament

Which ligament is formed by the flexor retinaculum?

Transverse carpal ligament

What structure lies superficial to the volar plate and adds stability to the fingers?

Transverse metacarpal ligament

What bone does the first metacarpal articular with?

Trapezium