Quiz 6 Wrist & Hand- Biomechanics

Which of the following muscles has the ability to flex the metacarpal phalangeal joints of the fingers?

-FDP -FDS -Lumbrical

Which of the following muscles CAN create motion at the interphalangeal joint (IP) of the thumb?

-FPL -EPL -Lumbricals -Palmar Int -Dorsal Int

Flexion of the fingers requires stabilization of the wrist by the wrist extensors. Without the synergistic contraction of the wrist extensors, the wrist would flex, and the strength of the grip would be diminished. Active flexion of the fingers and flexion of the wrist leads to a condition in which the finger flexor muscles can no longer shorten or develop tension. This condition is known as: -what about the extensors, what would they be?

-active insufficient -passive insu

What structures make up the triangular fibrocartilage complex (TFCC)? aka *ulnocarpal complex*

-articular disc -meniscal extension to triquetrum -ulnar collateral ligament -palmar ulnocarpal ligament

-extrinsic plus position - (intrinsic minus) contraction of only? -intrinsic plus position - contraction of only?

-ex (curl up) -in (L)

The triangular fibrocartilage complex or TFCC is an area of the wrist that is prone to developing tears or instability. Which of the following structures is NOT part of the TFCC?

-palmar RADIOcarpal lig

Describe MCP ADD of the proximal phalanx of 2 digit? -a on x

-proximal phalanx rolls and glides in direction of movement -phalanx rolls and glides ULNAR with 2nd digit adduction

Describe MCP ABD of the proximal phalanx of 2 digit? -a on x

-proximal phalanx rolls and glides in direction of movement -phalanx rolls and glides radially with 2nd digit abduction

finger pad to thumb pad is called? finger *tip* to thumb tip is called?

-pulp to pulp PINCH -tip to tip pinch

Metacarpal phalangeal stability is maintained through an interaction of 3 connective tissue structures. Which of the following structures is part of the mechanism that increases MCP stability?

-transverse metacarpal lig -volar plates -radial and ulna collateral lig

median nerve injury -extensors draw thumb back into plane of palm; ED extends MCPs; most finger flexors lost...leads to?

Ape hand

This is a characteristic hand position related to a lesion of one of the main nerves that innervates the muscles of the hand and forearm. When the individual attempts to extend the fingers, the index and middle fingers extend, but the fourth and fifth digits remain in a claw position. This deformity has been called the Bishop's hand or *Benedictine* hand. This hand position is caused by a lesion in which nerve?

Ulna nerve

The carpometacarpal and intermetacarpal joints are primarily __________ joints and allow the motions of __________:

planar, cupping and flattening of the palm

The RADIOCARPAL or proximal wrist joint consists of the proximal row of carpal bones articulating with the radius and the ulna/triangular fibrocartilage. Which of the following statements best describes the arthrokinematics that occur during wrist FLEXION? -x on a

proximal row of carpal rolls volar and glide dorsal

The hand is capable of many power grips and precision grips. This is a precision grip where the thumb, index finger, and middle finger surround an object such as a pencil. This grip is called the:

3 point chuck

what muscle att to pisiform and tendon of FCU? what 2 muscle att to hook of hamate?

ABD-DM FDM and O-DM

Which of the following muscles cannot create motion at the interphalangeal joint (IP) of the thumb?

ABD-PL

what muscle ABD 2,3,4 and extend IP? Lumbricals action?

Dorsal Interossei flex MCP and extend IP

This muscle is both a wrist extensor and a wrist radial deviator. However, it is located closer to the central axis of the hand than other radial deviators. Thus, it's role as a radial deviator is diminished. It functions better at preventing flexion of the wrist when the finger flexors are contracting and preventing flexion of the wrist when the palmaris longus is contracting.

ECRB

This tendon grooves the ulnar side of Lister's tubercle as it passes through tunnel 3 and then moves distally to form one side of the anatomic snuffbox?

EPL

No extrinsic muscle of the wrist and hand attaches to any of the carpal bones with the exception of this muscle that attaches to the pisiform?

FCU

This is the only muscle that has the ability to flex the distal interphalangeal joint. A tear or avulsion of this muscle leads to a condition called JERSEY or sweater finger in which the distal interphalangeal joint cannot be actively flexed:

FDP

Flexor tendon: -zone II - surgical NO MANS LAND secondary to poor circulation and split of?

FDS

The collateral ligaments of the metacarpal phalangeal joints tighten as the joint moves into this position preventing metacarpal phalangeal abduction. This position is also the close packed position for the metacarpal phalangeal joints:

Full flexion

These muscles ADDuct the metacarpal phalangeal joints bringing the fingers toward the middle finger, the main axis of the hand:

Palmar Interossei

These are all? -hook grasp - holding handle of suitcase -cylindrical grasp - holding a can of soda -fist grasp - holding and hanging from a high bar -spherical grasp - holding a soft ball -hammer grasp - holding a hammer

Power grip: thumb adducted against closed fingers

The carpometacarpal joint of the thumb consists of the base of the 1st metacarpal and the trapezium carpal bone. The configuration of this joint is a saddle joint. Which of the following statements best describes the arthrokinematics that occur during THUMB ABD? -x on a: *over do the motion*

base of proximal phalanx rolls palmarly and glides dorsally

Contraction of the extensor digitorum in isolation, without the help of the hand intrinsics, leads to the extrinsic plus position of the hand. This position involves: -MCP? -IP? -DIP?

flexion extension extension

Extensor tendon: -zone I - laceration of terminal extensor tendon; called?

mallet finger

The RADIOCARPAL or proximal wrist joint consists of the proximal row of carpal bones articulating with the radius and the ulna/triangular fibrocartilage. Which of the following statements best describes the arthrokinematics that occur during wrist EXTENSION: -x on a

proximal row of carpals rolls dorsally and glides volarly

Radiocarpal: -radial deviation arthrokinematics?

proximal row rolls radial and glides ulnar

Radiocarpal: -ulnar deviation arthrokinematics? x on a

proximal row rolls ulnar and glides radial

This position is the OPEN packed position for the metacarpal phalangeal joints?

slight flexion

During wrist flexion the capitate pivots so that a depression forms on the dorsum of the wrist at the level of the proximal portion of the capitate. The pivoting occurs because the 2 ends of the capitate move in different directions. Which of the following best describes the movement of the *capitate* at the MIDCARPAL joint during wrist FLEXION?

the PROXIMAL capitate roll volar and glide dorsal while the distal capitate glides volar with the *trapezium* that is gliding in the same direction

During wrist extension the capitate pivots so that a depression forms on the dorsum of the wrist at the level of the proximal portion of the capitate. The pivoting occurs because the 2 ends of the capitate move in different directions. Which of the following best describes the movement of the *capitate* at the MIDCARPAL joint during wrist EXTENSION?

the PROXIMAL capitate rolls dorsally and glides volarly while the DISTAL capitate glides dorsally with the *trapezoid* that is gliding in the same direction

Which of the following statements best describes the arthrokinematics that occur during THUMB EXTENSION? -a on x: EASY

the base of the 1st metacarpal rolls and glides radially

Which of the following statements best describes the arthrokinematics that occur during THUMB FLEXION? -a on x: EASY

the base of the 1st metacarpal rolls and glides ulnarly

Which of the following statements best describes the arthrokinematics that occur during THUMB ADD? -x on a *over do the motion*

the base of the 1st metacarpal rolls dorsal and glides volar

The metacarpal phalangeal joint consists of the base of the proximal phalanx and the head of the metacarpal joint. Which of the following statements best describes the arthrokinematics that occur during finger EXTENSION? -a on x

the proximal phalanx rolls and glides dorsaly

The metacarpal phalangeal joint consists of the base of the proximal phalanx and the head of the metacarpal joint. Which of the following statements best describes the arthrokinematics that occur during finger FLEXION: -a on x

the proximal phalanx rolls and glides volarly (palmar)

Metacarpal phalangeal stability is maintained through an interaction of 3 connective tissue structures. Which of the following structures is NOT part of the mechanism that increases MCP stability

transverse carpal ligament

radial nerve injury: -loss of wrist extensors leads to?

wrist drop