Functional Anatomy Iii

Front 1

Role of Foot & Ankle:

Back 1

- support body weight
- rigid lever for propulsion
- adapt to uneven surfaces
- absorb shock at contact
- absorb rotation of body when fixed

Front 2

Joints of Ankle & Foot

Back 2

• Talocural (tibiotalar)
• Subtalar
• Midtarsal (multiple joints)
26 bones, 30 joints, 100 ligaments, 30 muscles...and 2 days of lecture!!!

Front 3

What motion occurs at the talocrural joint?

Back 3

Uniaxial hinge - Dorsi and plantar flexion (in sagittal plane)

Foot moves in open chain, tibia moves in closed chain

Front 4

Rearfoot includes

Back 4

Calcaneus and talus

Front 5

Midfoot includes

Back 5

navicular, cuboid, and cuneiforms

Front 6

Forefoot includes

Back 6

Metatarsals and phalanges

Front 7

What motion occurs at the subtalar joint?

Back 7

Calcaneal inversion and eversion

Front 8

Motions of open chain pronation?

Back 8

Eversion, dorsiflexion, and abduction

Front 9

Motions of open chain supination?

Back 9

Inversion, plantarflexion, adduction

Front 10

(in closed chain?) Pronation/Eversion coincides with leg ___ & ____ ___

Function

Back 10

flexion and internal rotation

Absorbs lower extremity rotations/shock

Front 11

(in closed chain?) Supination/Inversion coincides with leg ___ and ___ __
Provides ___

Back 11

coincides with leg extension and external rotation

Front 12

Differences in closed chain and open chain pronation

Back 12

Closed - talus moves on calcaneus
Cause: weight bearing
involves eversion, plantar flexion, and adduction?

Open - Calcaneus moves on talus
Cause: muscular
Involves eversion, dorsiflexion, and abduction?

Front 13

Midtarsal joints

"Open" or "locked"

Back 13

Calcaneocuboid
Talonavicular

Joints are loose, more mobility in midfoot (adapt to terrain)
"open" in normal stance - calcaneocuboid axis and talonavicular axis are parallel.
"locked" in supination, when axis lines cross

Front 14

In the gait cycle, when do pronation and supination of the foot occur?

Back 14

Supination at heel contact of stance phase
Pronation at midstance and propulsion of stance phase (provides absorption)
Supination during toe-off and swing phase. (provides rigid lever)

Pronation accompanied by internal rotation of leg

Front 15

Plantarflexors

Back 15

Gastrocnemius - medial and lateral head
Soleus
Plantaris
Peroneus (fibularis) longus and brevis
Tibialis Posterior
Flexor Digitorum Longus

Front 16

Gastrocnemius
O/I/A

Back 16

Medial lateral condyles of femur TO calcaneus

Plantarflexion
(and leg flexion)

Front 17

Soleus
O/I/A

Back 17

Upper posterior tibia, fibula, interosseous membrane TO calcaneus

Plantarflexion

Front 18

Plantaris
O/I/A

Back 18

Linea aspera of femur TO calcaneus

Assist plantar flexion

Front 19

Peroneus longus
O/I/A

Back 19

Lateral condyle of tibia, upper lateral fibula TO 1st cuneiform; lateral 1st metatarsal (Crosses on the bottom of the foot)

Assist plantar flexion,
PM: Forefoot abduction, Eversion

Front 20

Peroneus (fibularis) brevis

Back 20

Lower lateral fibula TO 5th metatarsal

Assist ankle plantar flexion
PM: eversion

Front 21

Tibialis Posterior

Back 21

Upper posterior tibia, fibula, interosseous membrane TO inferior navicular (tendon passes on medial side of calcaneus)

Assist plantarflexion
PM: inversion

Front 22

Flexor Digitorum Longus

Back 22

Posterior tibia TO distal phalanx of toes 2-5

Assists plantarflexion and inversion

Front 23

Dorsiflexors

Back 23

Tibialis Anterior
Extensor Digitorum Longus
Extensor Hallucis Longus
Peroneus tertius (the third fibularis)

Front 24

Tibialis Anterior

Back 24

Upper lateral tibia, interosseus membrane TO medial plantar surface of 1st cuneiform

PM: dorsiflexion and inversion

Front 25

Extensor Digitorum Longus

Back 25

Lateral condyle of tibia; fibula; interosseus membrane TO dorsal expansion of toes 2-5

Assist dorsiflexion
PM extension of toe 2-5, eversion

Front 26

Extensor Hallucis Longus

Back 26

Anterior fibula; interosseous membrane TO distal phalanx of big toe

Assists dorsiflexion
PM: big toe extension, forefoot adduction

Front 27

Peroneus tertius

Back 27

Lower anterior fibula; interosseous membrane TO base of 5th metatarsal
(melds with extensor digitorum longus)

PM dorsiflexion and eversion (all peroneus evert)

Front 28

Foot Invertors

Back 28

Tibialis Anterior
Tibialis Posterior
Flexor digitorum longus
Flexor hallucis longus

Front 29

Foot Evertors

Back 29

Peroneus (fibularis) longus, brevis, and terius
Extensor digitorum longus

Front 30

What type of ligament sprain is most common in the ankle, and which ligament is sprained?

Back 30

Inversion ligament sprains are most common, with the anterior talofibular ligament being most often injured.
If the Ant. Inf. Talofibular lig. isn't injured, it's called a high ankle sprain.

Front 31

What is injured in an eversion sprain of the ankle?

Back 31

The deltoid ligament (made up of anterior talotibial, tibionavicular, and calcaneotibial)

Front 32

What muscles are involved in shin splints and what's going on?

Back 32

Tibialis posterior or anterior (medial or lateral pain)
Peiostitis or tendonitis

Front 33

Intrinsic foot muscles

Back 33

Lumbricales
Plantar interossei
Dorsal interossei

Front 34

Lumbricales

Back 34

Tendon of flexor digitorum longus TO base of proximal phalanx of toes 2-5 (on plantar surface)
Flexion of proximal phalanx 2-5

Front 35

Dorsal Interossei

Back 35

Sides of metatarsals TO lateral side of proximal phalanx
Flexion of proximal phalanx
Abduction of toes 2-4
Adduction of 2nd toe

Front 36

Plantar Interossei

Back 36

Medial side of 3-5 metatarsal TO medial side of proximal phalanx of toes 3-5
Abduction of toes 3-5

Front 37

Muscle Strain

Back 37

Overstretch of muscle or tendon
Partial or complete tear in the muscle, tendon

Front 38

Stress Fractures in the foot/leg because

Back 38

Muscles become fatigued and are unable to absorb added shock

Tibia: Compression
Fibula: Tension
Metatarsals: Bending

Front 39

Tendinosis can be in these locations

Back 39

Achilles tendinitis
Anterior Tibialis Tendinitis (front of ankle)
Peroneal tendinitis (lateral side)

Front 40

What makes up the shoulder complex and how is it attached to the rest of the body?

Back 40

girdle and joint (glenohumeral)

Attached at sternoclavicular joint, otherwise relies on muscular attachments

Front 41

Joints in shoulder complex

Back 41

True joints:
Sternoclavicular
Acromioclavicular
Glenohumeral

Functional (physiological joint: Scapulothoracic (ST)

Front 42

Shoulder girdle movements

Back 42

Elevation/depression (frontal plane)
Protraction/retraction (transverse)
Upward/downward rotation (scap only, frontal)
Posterior/anterior rotation (clavicle only, sagittal)

Front 43

Relationship between scapular and humeral motion

ratio

Back 43

called scapulohumeral rhythm

Any arm elevation above 30-60 degrees ~ 2:1 ratio of humeral to scapular motion

Front 44

Sternoclavicular joint

type, motions

Back 44

"saddle-like" gliding/plane joint

Elevation/depression
Pro/retraction
Ant/poteior rotation (only posteriorly rotates from resting position)

Front 45

Acromioclavicular (AC) joint

Type, motions

Back 45

Gliding/plane joint

Elevation/depression
Pro/retraction
Upward/downward rotation (of scap?)

Front 46

Scapulothoracic (ST) "joint" motions

Back 46

Elevation/depression
- Need elev at SC & AC joints
Pro/retraction
- SC & AC joints
Upward/downward rotation
- Requires posterior rotation at SC joint and upward rotation at AC joint

Front 47

Scaption

Back 47

Arm motion in scapular plane
Most energetically efficient motion of arm occurs in scapular plane (about 35 degrees)
Easier on joints

Front 48

Scapular Movers (muscles) to focus on

Back 48

Upper, middle, and lower trapezius
Rhomboids (major and minor)
Levator Scapulae - main elevator
Serratus Anterior
Pectoralis Minor
Subclavius

Front 49

Common injuries to shoulder girdle

Back 49

Clavicle fracture
SC joint separation
AC joint separation
Winged scapula

Front 50

Trapezius

Back 50

Upper, middle, and lower fibers

Occipital Bone; ligamentum nuchae; spinous process of C1-T12 TO acromion process; spine of scpula, lateral clavicle

Upper - Scapular elevation
Lower - Scapular depression
All - scapular adduction (retraction), upward rotation (create force couple for it)

Front 51

Rhomboids

Back 51

Major and Minor

Spinous process of C7, T1-T5 TO medial border of scapula

Scapular elevation, adduction/retraction, and downward rotation

Front 52

Levator Scapulae

Back 52

Transverse process of C1-C4 TO superior angle of scapula

Main elevator of scapula
Assists in adduction and downward rotation

Front 53

Serratus Anterior

Back 53

Ribs 1-8 TO underside of scapula along medial border

Of Scapula:
Elevation? maybe some fibers
Protraction
Upward rotation

Front 54

Pectoralis Minor

Back 54

Ribs 3-5 TO coracoid process

Scapular depression, protraction, downward rotation

Front 55

Subclavius

Back 55

Costal cartilage of rib 1 TO underside of clavicle

Scapular depression

Front 56

Features of the Glenohumeral joint capusule

Back 56

Labrum may provide 50% of the depth of the glenoid fossa
Axillary pouch allows for downward motion during rotation
Ligaments stabilize

Front 57

Glenohumeral ligaments
Where?
Resist?

Back 57

front of joint capsule
As a whole resist anterior displacement and lateral rotation

Front 58

Coracohumeral Ligament
Where?
Resists?

Back 58

Coracoid process TO greater and lesser tubercle of humerous
Resists inferior displacement and lateral rotation

Front 59

Transverse Humeral Ligament
Where?
Resists?

Back 59

Across bicipital groove

Stabilizes tendon of long head of biceps in intertubercular groove

Front 60

Rotator Cuff muscles

Back 60

Infraspinatus
Teres Minor --- Pull into joint and down
Subscapularis

Supraspinatus -- pulls into joint, and contributes to abduction

Tendons blend with and reinforce glenohumeral joint capsule to form a 'cuff'
- control motion, like 6 deep external rotators in hip
Pulls humerus into joint, stabilizing during arm flexion and abduction, esp. initial stages.

Front 61

What would happen without inferior slide at shoulder joint

Back 61

1cm superior roll with only 22 degrees of abduction -- impingement

Front 62

Shoulder Joint Impingement

Back 62

Compression of tissue between greater tubercle and acromion process (only 1 cm of space)
Occurs with abduction and internal rotation (external rotation necessary for full abduction)
Happens less in scaption plane (~45 degrees)

Front 63

Possible outcomes of shoulder impingement

Back 63

Subacromial bursitis - bursa above head of humerus is irritated
Myositis ossificans - calcification of muscle
Supraspinatus strain/tear

Front 64

What shoulder girdle motion occurs with the glenohumeral joint motion of flexion?

Back 64

Elevation, upward rotation, and protraction
Posterior clavicular rotation

Front 65

What shoulder girdle motion occurs with the glenohumeral joint motion of extension?

Back 65

Depression, downward rotation, retraction
Anterior clavicular rotation

Front 66

What shoulder girdle motion occurs with the glenohumeral joint motion of Abduction?

Back 66

Elevation, upward rotation, and protraction
Posterior clavicular rotation

Front 67

What shoulder girdle motion occurs with the glenohumeral joint motion of adduction?

Back 67

Depression, downward rotation, retraction
Anterior clavicular rotation

Front 68

What shoulder girdle motion occurs with the glenohumeral joint motion of horizontal adduction?

Back 68

Elevation, upward rotation, and protraction
Posterior clavicular rotation

Front 69

What shoulder girdle motion occurs with the glenohumeral joint motion of horizontal abduction?

Back 69

Elevation, upward rotation, and retraction
Posterior clavicular rotation

Front 70

What shoulder girdle motion occurs with the glenohumeral joint motion of internal rotation?

Back 70

Above 90 degrees, same as flexion/abduction (Elevation, upward rotation, and protraction
Posterior clavicular rotation)
In anatomical position, minimal shoulder girdle contribution

Front 71

What shoulder girdle motion occurs with the glenohumeral joint motion of external rotation?

Back 71

Above 90 degrees, same as flexion/abduction (Elevation, upward rotation, and protraction
Posterior clavicular rotation)
In anatomical position, minimal shoulder girdle contribution

Front 72

Muscle actions of pectoralis major, depending on position of limb at that moment. Action in transverse plane?

Back 72

Clavicular head of pec major can flex shoulder to 90 degrees
Sternal head can extend shoulder to 90 degrees

Medial/internal rotation

Front 73

Humeral Flexors

Back 73

Anterior Deltoid (ab, flex, horadd, inrot)
Pec Major, clavicular head (inrot, horadd, flex)
Biceps Brachii (flex, ab)
Coracobrachialis (flex, horadd)

Front 74

Humeral Extensors

Back 74

Posterior Deltoid (ab, ext, horab, exrot)
Pectoralis Major, Sternal head (inrot, horadd, ext)
Latissimus Dorsi (inrot, add, ext)
Teres Major (inrot, ext, add)
Triceps Brachii LH (ext)

Front 75

Humeral Abductors

Back 75

Deltoid (ab)
Supraspinatus (ab, exrot from neutral only)

Front 76

Humeral Adductors

Back 76

Latissimus Dorsi (inrot, add, ext)
Teres Major (inrot, ext, add)
Pectoralis Major (inrot, horadd, flex, ext)

Front 77

Horizontal Abductors of the humerus

Back 77

Posterior Deltoid (ab, ext, orab, exrot)
Infraspinatus (exrot, horab)
Teres Minor (exrot, horab)

Front 78

Horizontal Adductors of the humerus

Back 78

Anterior deltoid (ab, flex, horadd, inrot)
Pectoralis Major (inrot, horadd, flex, ext)
Coracobrachialis (horadd, flex, add)

Front 79

Internal Rotators of the Humerus

Back 79

S.P.L.A.T.

Subscapularis
Pectoralis Major
Latissimus Dorsi
Anterior Deltoid
Teres Major

Front 80

External Rotators of the humerus

Back 80

P.I.T.s

Posterior deltoid
Infrasinatus
Teres Minor

Supraspinatus, but only from anatomical position

Front 81

Acting together, the clavicular head of the pec major, anterior deltoid, and lh of biceps brachii would ___ the humerus

Back 81

Flex

Front 82

Working together, the actions of the upper fibers of the trapezius, middle deltoid, and supraspinatus muscles will ___ the humerus

Back 82

Abduct

Front 83

Starting from a flexed position of the humerus at 90 degrees, the actions of the posterior deltoid, teres minor, infraspinatus, rhomboids, and middle fibers of the trapezius will ___ the humerus and ___ the scapula

Back 83

Horizontally abduct the humerus and retract the scapula

Front 84

4 Joints of the elbow/forearm complex

Back 84

humeroulnar (ulnohumeral in book)
humeroradial (radiohumeral)
proximal radioulnar
distal radioulnar

interaction between these joints increases the range of effective hand placement

Front 85

Does biceps brachii or brachialis have a larger contact area on the humerus?
What other muscle(s) has/have a large contact area?

Back 85

Brachialis
Triceps

Front 86

Which epicondyle do the extensors attach to?

Back 86

The lateral epicondyle of the humerus (supinator for instance)

Front 87

What is the distal attachment of the biceps?

Back 87

The biciptital tuberosity on the radius

Front 88

What types of joints are the superior radioulnar joint and ulnarhumeral joint?

Back 88

pivot and modified hinge

Front 89

What is the purpose of the interosseus membrane?

Back 89

Transfers force between radius and ulna, and provides site for muscle attachment

Front 90

Define carrying angle, the two types, and list the norm for women

Back 90

Angle between the humerus and ulna in extension
Can have lateral angulation (cubitus valgus), where the ulna angles out to the side, or medial angulation (cubitus varus), where the ulna angles in toward the midline

Related to a person's ability to extend the forearm fully

Front 91

Taut in forearm extension and flexion (primarily posterior fibers), providing flexibility
Resists laterally applied (medially driven, valgus) forces

Back 91

Medial/ulnar collateral ligament

Can be ruptured by valgus force, causing lateral angulation of segment (fall on forearm)

Front 92

Resists medially applied (laterally driven, varus) forces, taut in extremes of forearm flexion

Back 92

Lateral/radial collateral ligament

Front 93

Resists radial distraction
Attached to joint capsule, lateral collateral ligament, and supinator

Back 93

Annular ligament (ring around radius, lined with cartilage)

Injury is called nursemaid's elbow, radial head subluxation

Front 94

Primary flexors of the elbow/forearm complex

Back 94

biceps brachii
brachialis
brachioradialis
pronator teres

Front 95

What puts the biceps brachii into a position of active insufficiency?
Passive insufficiency?

Back 95

Flexion of arm and forearm (reach back behind head)
extension of arm and forearm

Front 96

Biceps Brachii
Origin/Insertion
Action

Back 96

LH: Head of humerus (?, through intertubercular groove)
SH: Coracoid process of scapula
TO
Radial tuberosity

Flexion of forearm and arm (2-joint muscle)

Front 97

Elbow and radioulnar joint position affects bicep brachii activity
not used for supination until ____ degrees of flexion

Back 97

about 90 degrees (because of angle of action)

Front 98

What muscle is the "workhorse of forearm flexion"?

Back 98

Brachialis, its only action is forearm flexion, has a large area of attachment on humerus (PCA = 7cm2, compared with 2.5 cm2 for LH biceps)
Unaffected by pronation and supination of forearm

Front 99

Which is the longest elbow flexor, with the largest internal moment arm

Back 99

Brachioradialis
from ridge above lateral epicondyle to lateral styloid process (of radius)
Farthest from axis of rotation

Front 100

Which part of the triceps is a 2-joint muscle?
Under what circumstances would it experience passive insufficiency?
Active insufficiency?

Back 100

The long head
Passive in flexion of arm and forearm (reaching back behind head)
Active - extension

Front 101

Which part of the triceps is the "workhorse"?

Back 101

Medial head - active at all positions, speeds

Front 102

Which muscle is first to activate in forearm (or arm) extension?

Back 102

Anconeus (active at low force requirements)
Then medial head of triceps
provides graded control

Front 103

Benefit of 2-Joint Muscle Function: For Flexion and elbow extension (as in pushing on a door):

Back 103

efficient +/- work so takes load off 1 joint muscles recruited as force requirements increase

long head of the triceps brachii transfers power from shoulder (where it's an antagonist) to elbow (where it's an agonist
Maintain optimal length!

Front 104

Where do forearm pronators attach? Which one contributes most?

Back 104

Pronator teres and pronator quadratus attach to radius (check with tables)
Quadratus is the workhorse
Also assistance by palmaris longus and ___

Front 105

Supinators of the forearm

Back 105

Supinator (the workhorse)
Biceps brachii and others assist

Front 106

Is the biceps brachii a more efficient forearm flexor in supination or semiprone?

Back 106

Supination

Front 107

Injuries to elbow and forearm complex
looks like balled-up muscle, hard to heal, can be caused by traumatic fall (outstretched) or chronic repetitive motion

Back 107

Biceps tendon rupture

Front 108

Injuries to elbow and forearm complex
"little league elbow", caused by overuse of wrist flexors

Back 108

Medial epicondylosis

Front 109

Injuries to elbow and forearm complex
"tennis elbow," extensor tendons irritation

Back 109

Lateral epicondylosis

Front 110

Injuries to elbow and forearm complex
caused by overuse of wrist flexors, shows up on x-ray (I believe)

Back 110

Avulsion of medial epicondyle

Front 111

Injuries to elbow and forearm complex
"nursemaid elbow"

Back 111

Radial head subluxation
Dislocation of radial head, may pull out of annular ligament, easy to put back in place

Front 112

Which wrist joint provides most of the motion in extension?
Flexion?

Back 112

Radiocarpal joint
Mid-carpal joint (either motion occurs first here)

Front 113

Where is the mid-carpal joint?

Back 113

Between the 4 upper and 3 lower carpal bones (pisiform doesn't count)

Front 114

Which is the primarily loaded carpal during closed kinetic chain activities?

Back 114

the Scaphoid, receives about 80% of force/load
Blood supply isn't good

Front 115

Why is there more ulnar deviation than radial?

Back 115

bony congruence and ulnar tilt/gap

Front 116

What is the origin of wrist flexors?
extensors?

Back 116

medial epicondyle
lateral epicondyle (extensors)
can feel it on your arm!

Front 117

1st part of wrist/finger muscle nomenclature is primary action
they are...

Back 117

flexor
extensor
[abductor
adductor
opponens]
[for fingers muscles only]

Front 118

2nd part of wrist/finger muscle nomenclature is joint (or digit) which elicits action

Back 118

Carpi
Digitorum
Pollicis (thumb)
Indicis (index finger)
Digiti minimi (pinky)

Front 119

3rd part of wrist/finger muscle nomenclature is site (side) of insertion for wrist movers

Back 119

ulnaris
radialis

Front 120

Sometimes part of wrist/finger muscle nomenclature

Back 120

Qualifier...
Longus (for finger muscles, indicates extrinsic)
Brevis

Front 121

Muscles acting at wrist in the sagittal plane - Flexors

Back 121

Flexor carpi radialis
Flexor carpi ulnaris
Assisted by
– (Palmaris longus – absent 14% of population),
– Flexor digitorum superficialis & profundus (2 º)
– Flexor pollicis longus (2 º)

Front 122

Muscles acting at wrist in the sagittal plane - extensors

Back 122

Extensor carpi radialis longus & brevis,
Extensor carpi ulnaris
Assisted by
– Extensor digitorum (2 º)
– Extensor indicis (2 º)
– Extensor digiti minimi (2 º)
– Extensor pollicis longus (2 º)

Front 123

Muscles acting at Wrist- Frontal Plane
• Radial Deviation

Back 123

– Extensor carpi radialis longus & brevis
– Flexor carpi radialis
– Abductor pollicis longus
– Flexor pollicis longus
– Extensor pollicis longus & brevis

Front 124

Muscles acting at Wrist- Frontal Plane
• Ulnar Deviation

Back 124

• Ulnar Deviation
– Flexor carpi ulnaris
– Extensor carpi ulnaris

Front 125

Which of the following muscles would contribute to
radial deviation (wrist abduction)?
A. Extensor carpi ulnaris
B. Flexor carpi radialis
C. Extensor carpi radialis (longus and brevis)
D. All of the above
E. Only B and C are correct

Back 125

E. Only B and C are correct

Front 126

Which of the following muscles would contribute to
wrist flexion?
A. Flexor carpi radialis & flexor carpi ulnaris
B. Flexor digitorum (superficialis and profundus)
C. Extensor carpi radialis & extensor carpi ulnaris
D. All of the above
E. Only A and B are correct

Back 126

E. Only A and B are correct

Front 127

What role would having a clenched fist (as in around a
racket or a tool) play in the development of lateral
epicondylosis?
A. No role
B. Places finger extensors into lengthened position,
increasing stress on lateral epicondyle
C. Places finger flexors into shortened position,
increasing stress on lateral epicondyle
D. Co-contraction of flexors increases reciprocal
inhibition, increasing stress on lateral epicondyle

Back 127

B. Places finger extensors into lengthened position,
increasing stress on lateral epicondyle
Optimal grip position is ~30 degrees extension and slight ulnar deviation

Front 128

Why is grip strength stronger when in
extension?

Back 128

– Flexors have optimal LT relationship
– Passive tension in palmar joint capsule and
ligaments adds to force production
– If griping something large, need less extension
optimal position is 30 º extension and slight
ulnar deviation

Front 129

Tunnel Syndromes

Back 129

6 tunnels in wrist/hand complex
entrapment sites
• Carpal Tunnel - median nerve impingement
- 8 flexor tendons in capsule with median nerve and abductor pollicis longus surrounded by flexor retinaculum
– splint creates position of slight extension and radial
deviation to straighten tunnel, improves friction/tension on median nerve and tendons
- surgery often unsuccessful
• Canal of Guyon
- between pisiform and hook of hamate
- ulnar nerve runs through
- irritated by pressure in bike riding

Front 130

Name a common wrist fracture

Back 130

Colles' fracture (of radius)
caused by forced hyperextension (for instance in a fall)

Front 131

Functions of the hand/fingers

Back 131

• Important sensory organ, provides sensory
reception for tactile feedback
• Complex manipulation of objects, precision
and strength
• Opposable thumb

Front 132

Motion in Carpometacarpal (CMC) joints

Back 132

• Little motion for MC 2, 3
• Some motion for 4, 5
• Most motion for MC 1
(accounts for most of
thumb’s ROM)

Front 133

Metacarpophalangeal (MCP) joints

Back 133

• Digits 2-5: 2 dof
– Ellipsoid
• Digit 1: 1 dof
– Hinge

Front 134

Interphalangeal (IP) joints

Back 134

• 1 dof
• Digits 2-5
– Proximal (PIP)
– Distal (DIP)
• Thumb
– Only one (IP)

Front 135

Finger Extensors - extrinsic

Back 135

• Originate on lateral epicondyle
• Only one extensor digitorum (not L/B or
P/S)
• Tendons split and enter adjacent digit
• Result: generalized extensor mechanism,
less fine control than flexors
• Tendon joins w/connective tissue to form
dorsal expansion hood

Front 136

Why can't you lift your ring finger when your middle finger is bent under your hand?

Back 136

The two fingers have the same tendon of extensor digitorum (splits and goes to each) so it's very lengthened from the bent finger

Front 137

an
MCP flexor
that also
extends PIP and
DIP joints

Back 137

Lumbricales: know these intrinsic muscles!
on palmar surface, but then wrap to back of fingers to dorsal expansion hood

Front 138

Finger Flexors - extrinsic

Back 138

• Extrinsic finger flexors: arise from forearm
(antero-medial ulna, medial epicondyle of
humerus)
• Tendons of muscles arising in the forearm act
on PIP and DIP joints

Front 139

Finger Flexors - intrinsic

Back 139

• arise from tendons of long muscles, carpus,
or metacarpals
• Finger muscles arising from within the hand
act only on MCP joints

Front 140

Intrinsic hand muscles - interossei

Back 140

Interossei (flexor of MCP joint)
– Palmar - adduction
– Dorsal - abduction

Front 141

Make slides of some hand muscle origin/insertion/action

Back 141

Flexor digitorum profundus inserts on distal phalanges (deep=distal), superficialis to proximal