Kinesiology chap 13 The Hand

Which muscles form the Deep Palm Muscle group?

Adductor Pollicis, Dorsal Interossei, Palmar Interossei and the Lumbricales

MCP Joints of the fingers structure:

Biaxial Condyloid Joint; 2 degrees of freedom; The heads of the metacarpals 2-5 articulating with the bases of the proximal phalanges 2-5

CMC Joint of the thumb:

Biaxial Saddle Joint; 2 degrees of freedom

Osteokinematics of CMC joint of thumb:

CMC Flexion/Extension in the frontal plane; CMC Abduction/Adduction in the sagittal plane; opposition which is a combination motion of both

What two muscles form the lateral border of the snuffbox?

Extensor Pollicis Brevis and Abductor Pollicis Longus

What muscle forms the medial border of the snuffbox?

Extensor Pollicis Longus

Which muscles form the Hypothenar Muscle group?

Flexor Digiti Minimi, Abductor Digiti Minimi, and Opponens Digiti Minimi

Which muscles form the Thenar Muscle group?

Flexor Pollicis Brevis, Abductor Pollicis Brevis, and Opponens Pollicis

MCP and IP Joints of thumb Structure:

Head of the 1st metacarpal articulating with the base of the 1st proximal phalanx and the head of the proximal phalanx articulating with the base of the distal phalanx

MCP Joints of the fingers Osteokinematics:

MCP Flexion/Extension in the sagittal plane; MCP Abduction/Adduction in the frontal plane

MCP and IP Joints of the thumb Osteokinematics:

MCP flexion/extension in a plane between frontal and sagittal

Lumbrical Grip:

MCP joint flexed and PIP and DIP extended, with the thumb opposing the fingers holding the object; used when something needs to be held horizontally; example: holding a plate

Hand Sensation:

Median Nerve sensation is digits 1,2,3 and radial half of digit 4; Ulnar Nerve digits 5 and half of digit 4 on the anterior surface and all of lateral border of 5 and half of posterior surface of digit 4; Radial nerve is lateral border of digit 5 on anterior surface and posterior surface digits 1,2,4, and half of digit four but not the fingertips

CMC Joints of fingers structure:

Non-Axial Plane Shaped Synovial Joint

Flexor Pollicis Longus O, I, N, A

O: Anterior Radius I: Base of the Distal phalanx of digit 1 N: Medial Nerve A: CMC flexion digit 1; MCP flexion digit 1; IP flexion digit 1

Dorsal Interossei O, I, N, A

O: Between two adjacent metacarpals on posterior surface I: bases of the proximal phalanges of digits 2, 3, 4 and the Extensor Expansion; digit 3 has two insertions, one on each side N: Ulnar Nerve A: MCP abduction digits 2-4; assists with MCP flexion and PIP/DIP extension of digits 2-4 because of its insertion on the extensor expansion ("DAB"-Dorsal does ABduction)

Adductor Pollicis O, I, N, A

O: Capitate, base of the 2nd metacarpal, palmar surface of the 3rd metacarpal I: base of proximal phalanx of thumb N: Ulnar Nerve A: CMC adduction digit 1

Extensor Indicis O, I, N, A

O: Distal Ulna on the posterior surface I: Base of the distal phalanx of digit 2 via the Extensor Expansion with the ED N: Radial Nerve A: MCP extension digit 2; PIP extension digit 2; DIP extension digit 2

Flexor Digiti Minimi O, I, N, A

O: Hook of the Hamate and Flexor Retinaculum I: Base of the 5th proximal phalanx N: Ulnar Nerve A: MCP flexion digit 5

Opponens Digiti Minimi O, I, N, A

O: Hook of the Hamate and Flexor Retinaculum I: Ulnar border of the 5th metacarpal N: Ulnar Nerve A: Opposition of digit 5

Abductor Pollicis Longus O, I, N, A

O: Interosseous Membrane and middle Ulna I: Base of the first metacarpal on the Radial side N: Radial Nerve A: CMC abduction digit 1

Extensor Digitorum O, I, N, A

O: Lateral Epicondyle of Humerus at the Common Extensor Tendon I: Bases of distal phalanges 2-5 via the extensor expansion N: Radial Nerve A: MCP extension digits 2-5; PIP extension digits 2-5; DIP extension digits 2-5; assists wrist flexion

Extensor Digiti Minimi O, I, N, A

O: Lateral Epicondyle of Humerus at the Common Extensor Tendon I: Base of the distal phalanx of digit 5 N: Radial Nerve A: MCP extension digit 5; PIP extension digit 5, DIP extension digit 5

Flexor Digitorum Superficialis O, I, N, A

O: Medial Epicondyle of the Humerus at the Common Flexor Tendon, Coronoid Process of the Ulna and proximal anterior Radius I: sides of the middle phalanges of digits 2-5 (the tendons of the FDS split before inserting into the sides of the middle phalanges) N: Median Nerve A: MCP flexion digits 2-5; PIP flexion digits 2-5; assists wrist flexion

Extensor Pollicis Longus O, I, N, A

O: Middle posterior Ulna and Interosseous Membrane I: Base of the distal phalanx of the thumb on the posterior side N: Radial Nerve A: CMC extension digit 1; MCP extension digit 1; IP extension digit 1

Palmar Interossei O, I, N, A

O: Palmar surface of metacarpals 2, 4, 5 I: Base of proximal phalanx of same finger and the extensor expansion; there is no insertion on digit 3 N: Ulnar Nerve A: MCP adduction digits 2, 4, 5; assists with MCP flexion and PIP/DIP extension of digits 2, 4, 5 because of its insertion on the extensor expansion ("PAD" Palmar does ADduction)

Abductor Digiti Minimi O, I, N, A

O: Pisiform and tendon of the Flexor Carpi Ulnaris I: Base of the 5th proximal phalanx N: Ulnar Nerve A: MCP abduction digit 5

Extensor Pollicis Brevis O, I, N, A

O: Posterior distal Radius near the distal end and just below the APL I: Base of the proximal phalanx of the thumb on the posterior surface N: Radial Nerve A: CMC extension digit 1; MCP extension digit 1

Abductor Pollicis Brevis O, I, N, A

O: Scaphoid, Trapezium, and Flexor Retinaculum I: Base of the 1st proximal phalanx N: Median Nerve A: CMC abduction digit 1; has secondary role in flexing the thumb at the MCP and CMC joints

Lumbricals O, I, N, A

O: Tendon of FDP I: Extensor Expansion of ED muscle at proximal phalanx N: Lumbricals 1 & 2-Median Nerve; Lumbricals 3 & 4-Ulnar Nerve A: MCP flexion digits 2-5; PIP/DIP extension digits 2-5; known as lumbrical position

Opponens Pollicis O, I, N, A

O: Trapezium and Flexor Retinaculum I: Lateral surface of the 1st metacarpal N: Median Nerve A: Opposition of digit 1

FLexor Pollicis Brevis O, I, N, A

O: Trapezium and Flexor Retinaculum I: Base of the 1st Proximal Phalanx N: Median Nerve A: CMC Flexion digit 1; MCP Flexion digit 1

Flexor Digitorum Profundus O, I, N, A

O: upper ¾ Ulna on the anterior/medial surfaces from the Coronoid Process to 3/4 of the way down I: distal phalanges of digits 2-5 (the tendons of the FDP run through the split in the FDS on their way to the distal phalanges N: Median and Ulnar A: MCP flexion digits 2-5; PIP flexion digits 2-5; DIP flexion digits 2-5; assists wrist flexion

PIP and DIP joints of the fingers Osteokinematics:

PIP/DIP Flexion and Extension in the sagittal plane

Carpometacarpal Joint (CMC Joint) Digit 3

The Capitate articulating with the base of the third metacarpal

Carpometacrpal Joint (CMC Joint) Digits 4 and 5

The Hamate articulating with the base of the fourth and fifth metacarpal

Carpometacarpal Joint (CMC Joint) Digit 2:

The Trapezoid articulating with the base of the second metacarpal

CMC Joint of thumb Structure:

Trapezium articulating with the base of the first metacarpal; the Trapezium is concave in the sagittal plane and convex in the frontal plane; the base of the first metacarpal is the opposite shape

MCP and IP Joints of the thumb:

Uniaxial Hinge Joint

PIP and DIP Joints of the fingers structure:

Uniaxial Hinge Joints; 1 degree of freedom; The heads of the proximal and middle phalanges of digits 2-5 articulating with the middle and distal phalanges of digits 2-5

Power Grips:

Used when an object needs to be held forcefully when being moved; usually is an isometric contraction where no movement occurs between the hand and the object being moved; the movement usually occurs at a proximal joint segment; the fingers usually wrap around the object in one direction and the thumb in the other

Arches of the Hand:

When the hand is relaxed, the palm assumes a cupped position. This palmar concavity is due to the arrangement of the bony skeleton reinforced by ligaments. There are three arches responsible for this shape. They contribute to functions of various grasps

Flexor Retinaculum:

a fibrous band that spans the anterior surface of the wrist in a mediolateral (horizontal) direction; its main function is to hold these tendons close to the wrist, thus preventing the tendons from pulling away from the wrist (bow-stringing) when the wrist flexes; prevents the two sides of the carpal bones from spreading apart or separate

Pinch Grip:

a pad-to-pad grip involving the thumb and one finger, most commonly the index finger

Arthrokinematics of CMC Joint of thumb: Sagittal plane motion

abduction/adduction, the convex base of the first metacarpal moving on the concave trapezium in the opposite direction as the distal end of the bone (the can-opener stretch)

Release:

act of letting go of an object; requires the extensor muscles

Functional Position of the Hand:

based on length-tension relationship; wrist in 20-30 degrees of extension, MCP and PIP slightly flexed and thumb in opposition

Longitudinal Carpal 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

IP Flexion of the thumb:

bending of the IP joint so that the anterior surface of the first distal phalanx moves toward the anterior surface of the proximal phalanx

MCP Flexion digits 2-5:

bending that occurs between the metacarpals and proximal phalanges in the sagittal plane; moving anteriorly

DIP Flexion digits 2-5:

bending that occurs between the middle and distal phalanges

PIP Flexion digits 2-5:

bending that occurs between the proximal and middle phalanges; anterior movement through the sagittal plane

MCP Flexion of the thumb:

bending the MCP joint so the anterior surface of the first proximal phalanx moves closer to the palm in a bi-planer plane between the frontal and sagittal plane

Pad-to-Pad Grip:

bringing the pads of the thumb and one, or several, fingers together

Tip-to-Tip/Pincer Grip:

bringing the tip of the thumb up against the tip of another digit; example: picking up a coin or a needle

Opposition of the thumb:

combination of flexion and abduction to produce a movement where the tips of the 1st and 5th digits touch

Flexor Pollicis Longus line of pull:

deep muscle

Extensor Indicis line of pull:

deep muscle; crosses the wrist under the extensor retinaculum medial to the extensor digitorum muscle. This muscle allows us to point with our index finger while the other fingers are in a fist

Extensor Pollicis Brevis line of pull: .

deep on the posterior forearm and spans the wrist just medial to the abductor pollicis longus muscle. Without the function of this muscle, the thumb MCP joint remains in a flexed position

Extensor Retinaculum:

fibrous ligament traversing the posterior side of the wrist in a horizontal mediolateral direction; attaches medially to the styloid process of the ulna and to the triquetrum, pisiform and lateral side of the radius; holds the extensor tendons close to the wrist, especially during wrist extension

Spherical Grip:

fingers and thumb are slightly spread apart and adducted around an object; example: picking up a glass by its top, holding an apple, or doorknob

Arthrokinematics of CMC joint of thumb: Frontal plane motion

flexion/extension, the concave base of the first metacarpal moving on the convex Trapezium in the same direction as the distal end of the bone

The Hypothenar muscle group:

form the hypothenar eminence at the base of the fifth digit and act primarily on the little finger. Lateral side innervated by the ulnar nerve

Proximal Carpal Arch:

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

Lumbricals:

four deep muscles that have no bony attachment; proximally span the MCP joint anteriorly which allows them to flex the MCP joint; then pass posteriorly at the proximal phalanx to attach to the tendinous expansion of the ED muscle which allows them to extend at the PIP and DIP joints; this combined motion is referred to as the "tabletop position".

Dorsal Interossei:

four muscles that attach proximally to two adjacent metacarpals and distally to the base of the proximal phalanx; the third digit has two muscles-one on each side of the proximal phalanx which allows the third digit to abduct in either direction. The fifth finger is abducted by the abductor digiti minimi; they have important function in activities such as typing and playing the piano

Cylindrical Grip:

gives up the most precision for power; the fingers are flexed around an object in an orientation perpendicular to the forearm; the thumb wraps around the object in the other direction, overlapping the fingers; examples: holding a hammer, tennis racket, or wheelbarrow handle

Adductor Pollicis line of pull:

has two heads; the oblique head has its proximal attachments on the capitate and bases of second and third metacarpals; the transverse head arises from the distal 2/3rds of the palmar surface of the third metacarpal. The fibers of the two heads unite to attach on the ulnar side of the base of the proximal phalanx of the thumb. It gives much power to grasp objects because of its function in adduction of the thumb

Side-to-Side Grip:

involves an object being held between two adducted fingers, usually the index and middle finger; weak grip; example: twirling a pen, or holding a cigarette

Flexor Digitorum Profundus line of pull:

lies deep to the FDS muscle and together traverse the forearm and hand; runs beneath the FDS muscle until the Superficialis tendon splits into two parts at its insertion; it passes through this split and continues distally to its insertion

Opponens Pollicis line of pull:

lies deep to the abductor pollicis brevis muscle. Loss of thumb opposition is caused by damage to the median nerve and is referred to as "ape hand deformity." Located on the lateral side

Opponens Digiti Minimi line of pull:

lies deep to the other hypothenar muscles; on the lateral side

Flexor Digitorum Superficialis line of pull:

lies deep to the wrist flexors and palmaris longus muscle; it divides into four tendons and crosses the wrist; as it approaches its insertion it splits into two parts and attaches on each side of the middle phalanx of each finger

Abductor Pollicis Brevis line of pull:

lies just lateral to the Flexor Pollicis Brevis muscle, in the middle

The Thenar Group:

located at the base of the thumb; function to move the thumb. They form the thenar eminence, or the ball of the thumb; anterior muscle on the radial side is innervated by the median nerve

The Deep Palm muscle group:

located deep in the palm of the hand between the thenar and hypothenar muscles. They perform some of the more intricate motions that usually involve multiple muscles: adductor pollicis, the interossei (of which there are four dorsal and four palmar), and the lumbricals (of which there are also four muscles)

Extensor Pollicis Longus line of pull:

located deep in the posterior forearm; becomes superficial just before crossing the wrist; we use this muscle to pull the thumb back when a flat and open hand is needed (an example of this is clapping)

Abductor Pollicis Longus line of pull:

located deep on the posterior forearm; it becomes superficial just proximal to crossing the wrist; its action is abduction of the thumb at the CMC joint even though it is attached only to the metacarpal, because the distal joints (MCP and IP) allow only flexion/extension. Therefore, the thumb moves as one unit in the direction of abduction/adduction. Adducting the metacarpal also adducts the entire thumb; therefore, when referring to thumb abduction, adduction, opposition and reposition, it is implied that the action occurs at the CMC joint. Without this muscle, the thumb cannot be moved away from the palm. It also has a secondary action of extending the thumb

Extensor Digiti Minimi line of pull:

long, narrow muscle that is deep to the extensor digitorum and extensor carpi ulnaris muscles near its proximal attachment. It becomes superficial before crossing the wrist. It comes off the common extensor tendon on the lateral epicondyle of the humerus, crosses the wrist under the extensor retinaculum on its way to its insertion. It makes possible the isolated extension of the fifth finger.

CMC Extension of the thumb:

movement of the thumb away from the fifth digit in a plane parallel to the palm (frontal plane movement)

CMC Abduction of the thumb:

movement of the thumb away from the palm in a plane perpendicular to the palm (sagittal plane movement)

CMC Flexion of the thumb:

movement of the thumb toward the fifth digit in a plane parallel to the palm (frontal plane movement)

CMC Adduction of the thumb: )

movement of the thumb toward the palm in a plane perpendicular to the palm (sagittal plane movement

MCP Abduction digits 2-5:

occurs when the second, fourth and fifth fingers move away from the third digit, or when the third digit moves in either direction in the frontal plane

MCP Adduction digits 2-5:

occurs when the second, fourth, and fifth fingers move back toward the third digit in the frontal plane. There is no adduction for the middle finger. Returning to anatomical position of the third digit; instead, it is called abduction toward the ulnar side or abduction toward the radial side.

Hook Grip:

only power grip that doesn't use the thumb; flexion of digits 2-5 around an object in a hook-like manner; because the thumb is not involved, this may be the only functional power grip for an individual with a median nerve injury who cannot oppose the thumb; examples: holding the handle of a suitcase or bucket

Flexor Pollicis Brevis line of pull:

relatively superficial muscle, toward the midline

Flexor Digiti Minimi line of pull:

serves the same function on the little finger as the Flexor Pollicis Brevis does on the thumb; on the medial side of the eminence

Extensor Expansion Ligament/Extensor Hood:

small, triangular, flat aponeurosis covering the dorsum and sides of the proximal phalanx of the fingers; the extensor digitorum tendon blends into the expansion; is wider at its base over the MCP joint, actually wrapping over the sides; as it approaches the PIP joint, it is joined by tendons of the lumbricals and interossei muscles; it narrows toward its distal end at the base of the distal phalanx; the extensor digitorum, lumbricals and interossei muscles form an attachment to the middle or distal phalanx by way of the expansion; the extensor hood area, formed by the extensor expansion proximally, covers the head of the metacarpals and keeps the extensor tendon in the midline; Allows an action at further distal attachment that muscles that attach to it don't cross

Extrinsic Muscles of the Fingers:

span the wrist and cross the joints of the hands; their proximal attachment is above, or proximal to, the wrist joint; they have an assistive role in wrist function, but their primary function is at the thumb or finger; their names give much information about the function and location; pollicis means thumb, digitorum means digit

IP Extension of the thumb:

straightening of the IP joint so that the anterior surface of the first distal phalanx moves away from the anterior surface of the proximal phalanx

MCP Extension of the thumb:

straightening of the MCP joint so that the anterior surface of the first proximal phalanx moves away from the palm in a bi-planer plane between the frontal and sagittal plane

MCP Extension digits 2-5:

straightening that occurs between the metacarpals and proximal phalanges in the sagittal plane; moving posteriorly

DIP Extension digits 2-5:

straightening that occurs between the middle and distal phalanges

PIP Extension digits 2-5:

straightening that occurs between the proximal and middle phalanges; posterior movement through the sagittal plane

Extensor Digitorum line of pull:

superficial muscle on the posterior forearm and hand; passes under the extensor retinaculum; in the area of the metacarpals are interconnecting bands jointing the four extensor digitorum tendons; these bands limit independent finger extension

Abductor Digiti Minimi line of pull:

superficially just medial to the flexor digiti minimi muscle on the ulnar border of the hypothenar eminence; in the middle

Prehension:

the act of grasping an object; requires the flexor muscles; pushing with a flat hand is a non-prehension activity

PIP and DIP joints of the fingers Arthrokinematics:

the concave base of the middle and distal phalanges articulating with the convex heads of the proximal and middle phalanges moving in the same direction as the distal end of the bone

MCP and IP Joints of the thumb Arthrokinematics:

the concave base of the proximal and distal phalanx articulating on the convex metacarpal and proximal phalanx moving in the same direction as the distal end of the bone

MCP Joints of the fingers Arthrokinematics:

the concave base of the proximal phalanges articulating with the convex heads of the metacarpals moving in the same direction as the distal end of the bone

Cylindrical Grip Variation:

the fingers are flexed around the handle of an object in a graded fashion, with the fifth finger flexed the most and the second finger flexed the lease; the thumb lies parallel to the handle of the object; this grip still offers a lot of power, but also allows for more control of the object; example: holding a golf club or screwdriver

Metacarpophalangeal Joints (MCP Joints) digits 2-5:

the head of metacarpals 2-5 articulating with the base of the proximal phalanges 2-5

Metacarpophalangeal Joint (MCP Joint) Digit 1:

the head of the first metacarpal articulating with the base of the first proximal phalanx

Interphalangeal Joint (IP Joint) Digit 1:

the head of the first proximal phalanx articulating with the base of the first distal phalanx

Distal Interphalangeal Joints digits 2-5:

the head of the middle phalanges 2-5 articulating with the base of the distal phalanges 2-5

Proximal Interphalangeal Joints digits 2-5:

the head of the proximal phalanges 2-5 articulating with the base of the middle phalanges 2-5

Transverse Carpal Ligament:

the more distal and deep portion that covers the Carpal Tunnel; attaches to the Pisiform and Hook of the Hamate on the medial side and to the Scaphoid and Trapezium bones laterally; it arches over the carpal bones, forming a tunnel

Palmar Carpal Ligament:

the more proximal and superficial portion that holds the flexor tendons to the anterior wrist; its distal fibers blend with the Transverse Carpal Ligament; attaches to the Styloid Processes of the Radius and Ulna and crosses over the flexor muscles

Pad-to-Side Grip/Lateral Prehension:

the pad of the extended thumb presses an object against the radial side of the index finger; strong grip, but some precision is lost; UE prosthesis works this way; can be performed by a person who has lost thumb opposition; example: grasping a key to put into the ignition

Distal Carpal Arch:

the shallower arch made up of the metacarpal heads

Carpometacarpal Joint (CMC Joint) Digit 1:

the trapezium bone articulating with the base of the first metacarpal

Three-Jaw-Chuck/Tripod Grasp:

this is the most common form of precision grip; it is a pad-to-pad grip involving the thumb and two fingers, usually the middle and index fingers; example: holding a pen or pencil

Palmar Interossei:

three muscles that do not attach to or have funciton on digit 3; they pull the digits toward the midline of the hand, creating adduction motions. They play an important role in activities such as typing and playing the piano

The Carpal Tunnel:

tunnel created by the anterior concavity of the carpal bones and the overlying transverse ligament; tunnel through which the median nerve and nine extrinsic flexor tendons of the fingers and thumb (four tendons each of the flexor digitorum superficialis and flexor digitorum profundus and one tendon for the flexor pollicis longus) pass; carpal tunnel syndrome-front of the palm, digits 1,2,3 and the radial half of digit 4 is where symptoms will be felt (pain, numbness, tingling and muscle weakness and atrophy over time) because of pressure on the Median nerve

Precision Grips:

when an object needs to be manipulated in a finer movement, like threading a needle or holding a pen