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Brachial plexus and extemities

What are the two soft tissue compartments of the brachium, and what do they do? anterior (flexor) and posterior (extensor)
What separates the compartments of the brachium? intermuscular septum
What is the purpose for body compartments? prevents the spead of disease and allows for some function in case of an injury
Posterior compartment muscles Triceps brachii (long, lateral, and medial heads)
Which of the triceps muscles crosses 2 joints, and what are those joints? Long head, crosses the shoulder and elbow joints
In relation to the radial nerve where do the triceps muscles lie? lateral lies above the nerve, and the medial lies below it
What kind of muscle are the triceps muscles? Pennate muscles
Attachements of Triceps muscles infraglenoid tubercle (long); humeral shaft (lateral and medial); insert: olecranon process of ulna (all)
Triceps functions extension of the shoulder, extension of the elbow, stabilize inferior part of the shoulder joint in full abduction
What exercises can work the triceps muscles? push-ups and push-downs
What is the function of the triceps if you reverse the attachment points? movement of the trunk around a fixed point, in this case, the arm.
Anterior compartment muscles Biceps brachii (long and short head), brachialis, and coracobrachialis
Which of the anterior compartment muscles cross two joints, and what are those joints? Biceps (long and short heads) cross the elbow and ahoulder joints
What 3 muscles attach to the coracoid process? pec minor, coracobrachialis, and short head of the biceps
Biceps attachments O: supraglenoid tubercle and coracoid (short) I: radial tuberosity and fascia of medial forearm
The biceps act as an antagonist to what muscle? triceps
Biceps Functions flexion of the shoulder(short head), flexion of the elbow (forearm supinated), supination of forearm, stabilizes anterior portion of shoulder joint (tendon of the long head)
Supination moiving the hand into the palm up position, radius and ulna are parallel
Pronation moving of the hand into a palm down position, crossing the radius and ulna
Brachialis Attachments O: anterior humeral shaft I: ulnar tuberosity
Brachialis lies deep to what muscle? biceps
Brachialis Functions flexion of the elbow (all positions of the forearm)
What exercises work the brachialis and biceps muscles? Biceps: palm up curls Brachialis: palm down curls
Corachobrachialis attachments O:coracoid of scapula I:humeral shaft
Coracobrachialis functions flexion of the shoulder, elevation of the humerus
When flexing the shoulder, what muscle does coracobrachialis act as a synergist with? short head of biceps
When elevating the humerus, the coracobrachialis acts as a synergist with what muscle? deltoid (to prevent anterior translation of the humeral head)
Musculocutaneous nerve innervates__________ the anterior brachial muscles (biceps, brachialis and coracobrachialis)
When the musculocutaneous nerve crosses the elbow joint it becomes the ___________ lateral antebrachial cutaneous nerve
Extensor muscle origins common extensor tendon, lateral supercondylar crest of humerus, posterior surfaces of radial and ulnar shafts, posterior surface of interosseous membrane
Extensor muscle insertions MC's, phalanges, radial shaft, proximal ulna
Supinator and brachioradialis insertions radial shaft
Anconeus insertion proximal ulna
What innervates the extensor muscles? radial nerve
True or False: Forearm flexors and extensors are major movers of the elbow FALSE: forearm flexors and extensors are NOT able to move the elbow, even though they corss it
What is the major effect of forearm flexors and extensors on the elbow? Stabilizers
Why is the brachial plexus important to OT Because it innervates the entire upper extremity
What is the brachial plexus made of? Ventral rami
What is the brachial plexus? it is an intersection of cross-trading fibers of multiple spinal levels that lies deep to BOTH pec. mm. and exits between than anterior and middle scalenes
What structures run with the brachial plexus? axillary a. and v.
Redundancy allows for__________ continued function if there is an injury at one or more spinal levels
Ventral rami also form ________ intercostal nerves
What causes costoclavicular Syndromes? A depression or compression of the clavicle toward the first rib that may impinge the nerves against the rib
What are some effects of costoclavicular syndromes? possible motor and sensory deficits
What is a common cause of costoclavicular syndromes? heavy backpacks that compress the clavicle to the first rib
Ventral rami innervate: limbs, front and side of trunk
Dosal rami innervate back of trunk (erector spinae and skin)q
Parts of the brachial plexus Roots, trunks, divisions, cords, and branches
Roots=_________ Ventral ramiof C5-T1 (sometimes C4 & T2 are included)
Trunks "1st plexus," formed by the intersection of roots: superior, middle, inferior
What roots make up the superior trunk? C5+C6
What roots make up the middle trunk? C7
What roots make up the inferior trunk? C8+T1
What trunk lies on rib 1? inferior trunk
Which trunk is most likely to be affected by costoclavicular impingement? Inferior trunk
Divisions formed by the splitting of each trunk, forming 1 anterior and 1 posterior divisions for a total of 6 divisions (3 ant. & 3 post.)
When referring to divisions, their positons are relative to their position to the axillary a.
Cords formed by merger of divisions and are named due to their position around the axillary a.
Lateral cords most superior, from 2 upper ant. divisions
Posterior Cords behind axillary a. and formed from all 3 posterior divisions
Medial cords most inferior, anterior division of lower division only
Branches Named nerves, 5 major branches: musculocutaneous, median, ulnar, radial, axillary
Which branches for the "M" of the brachial plexus? Musculocutaneous, median, and ulnar
Where is the antebrachium located? forearm: from elbow to wrist
What are the soft tissue compartments of the antebrachium and what do they do? anterior (flexor)& posterior (extensor)
What separeates the compartments of the antebrachium? radius, ulna, and interosseus membrane
Antebrachial fascia is located_________ below the skin but above the mm. and envelopes the entire forearm
What are the functions of the antebrachial fascia? assist in venous return of blood to the heart; helps to direct/ contain muscle tendons and actions
How many muscles are there in the flexor compartment of the antebrchium? 8 total
what are the flexor compartment muscles of the antebrachium responsible for? flexion of the wrist and fingers; 2 pronate the forearm
True or False: Flexor compartment muscles have multiple tendons. True!
How many forearm flexor compartment muscles cross the wrist? 12 (6mm)
How many forearm flexor tendons go through the carpal tunnel? 10 tendons (4 mm)
Why are the muscle bellies of the forearm extensors closer to the elbow than the wrist? allows for more power because the bulk of the m. is close to the fulcrum (elbow) allowing for less NGR usage
Forearm flexor muscle origins (as a group) common flexor tendon, medial epicondyle of humerus; ant. surfaces of radial and ulnar shafts; ant. surface of interosseus membrane
Forearm flexor muscle insertions (as a group) carpals, MCs, phalanges; radial shaft
Innervation of the forearm flexors median and ulnar nn
What are the forearm extensor compartment muscles responsible for? extension of the wrist and fingers; supination of the forearm, flexion of the elbow, deviation of the ulna
Which extensor muscle supinates the forearm? Supinator
Which forearm extensor flexes the elbow? brachioradialis
Which forearm extensor deviates the ulna? anconeus
How many forearm extensor muscles are there? 12
How many forearm extensor tendons cross the wrist? 9mm = 12 tendons
What 3 forearm extensor mm. do not cross the wrist? supinator, anconeus, and brachioradialis
Forearm extensor muscle origins common extensor tendon, lateral epicondyle of the humerus; lateral supracondylar crest of humerus; post. surfaces of radial and ulnar shafts; post. surface of interosseous membrane
Forearm extensor muscle insertions MCs, radial shaft (supinator & brachioradialis); proximal ulna (anconeus)
Innervation of the forearm extensors radial n
True of False: Most forearm extensors cross the elbow, but they do not move it. True; at most they serve as stabilizers; Exceptions: brachioradialis, anconeus(?), extensor carpi radialis longus
Extensor carpi radialis longus is responsible for________ flexion of the elbow because it crosses in front of the elbow
Anconeus functions extension of the elbow; radial deviation of the ulna in pronations
What is radial deviation? moving toward the radius
What is ulnar deviation? moving toward the ulna
The elbow joint is made up of the intersection of _____ bones 3
In the elbow, the radius has free rotary motion on the _________, and is restricted to ___ degree of freedom on its ________ capitulum, 1, long axis
In the elbow, the articulation between the ulna and the trochlea is what kind of joint? Condylar or hinge joint
The articulation of the radius on the capitulum is what kind of joint? ball and socket
When are hinge joints in close-packed positions? full stability
Elbow ligaments joint capsule, ulnar lig., radial collateral lig., annular lig.
Where is the annular ligament located? surronding the head of the radius , keeping it on the head of the capitulum
When is the radial collateral ligament slack? in the flexed position
Where is the radial collateral lig. located? on the outside of the hinge joint
In general, collateral ligaments___________ are found at hinge joints in the limbs, are normally tightest in extension, stabilize the joint whe it's subjected to greatest loads
What are the elbow bursae? Subtendinous bursa and subcutaneous bursa
The subtendinous bursa___________ us below the tendon of the triceps and allows the radius to move easily
The subcutaneous bursa_____________ act as a buffer between the humerus, radius and ulna whe the elbo is in full flexion
The shafts of the radius and ulna form what kind of joint along their lengths? syndemosis joint
The interosseous membrane fibers are _______, and run primarily in what 2 directions? oblique, distally toward the radius and distally toward the ulna
The interosseous membrane fibers are tightest in the ___________ anatomical position
In the interosseous membrane, the fibers running distally to the radius are called oblique cord (proximally)
The oblique cord prevents what? traction of the radius/hand
When does dislocation of the radius occur during a traction injury? when there is an impingement of the annular ligament between the radius and capitulum
In the interosseous membrane, the firbers running distally toward the ulna________ make up the bulk of the membrane, prevent compression of the radius against the humerus
Compression of the radius occurs when the radius is driven in front of or to the side of the humerus
What 2 "linked" elements comrise the forearm? (humerus + ulna) + (radius+manus)
Pronation/supination is the movementof the RM around the HU
What are the major grips of the hand? power and precision
When would you use a power grip? when holding/using a hammer or squeezing an object
When is a precision grip most often used? writing
When does the strongest power grip occur? when the wrist is slightly extended (extensor tendons are loose, flexor tendons are tight)
True or false: forced flexion of the wrist weakens the power grip True
When is full extension of the fingers possible? when the wrist is slightly flexed
How many carpals are in the wrist? 8; 4 in the proximal row & 4 in the distal row
The proximal row of carpals attach to the radius
The distal of the carpals ________ supports finger
Proximal row carpals scaphoid, lunate, triangular, pisiform
Distal row of carpals trapezium, trapezoid, capitate, hamate
How many articulations are there between the carpals and metacarpals? 4- digits 4 and 5 both articulate with the hamate
What are the arches of the hand? longitudinal and transverse
The longitudinal arch is the natural curve from the wrist to the fingers; concave palm; conforms to objects graspes
The transverse arch is concave on the palm side, protects the nerves and vessels; runs transversely to longitudinal arch
What makes up the transverse arch? wedge shaped carpals (proximal and distal)
Without soft tissue, what will happen to the transverse arch? it will fall apart ("fallen arches")
What structure maintains the transverse arch? flexor retinaculum
Attachment points of the flexor retinaculum scaphoid tubercle, pisiform, trapezium tubercle, hook of the hamate
What structures are part of the radiocarpal joint? the radius, lunate, scaphoid, triangular fibrocartilage, and triangular
Separates the ulna from the triangular bone triangular fibrocartilage
The ulna articulates with the radius at __________ the radius at the distal radioulnar joint
What kind of joint is the wrist? Condylar (hinge)
Motions of the radiocarpal joint flexion/ extension (primary), radial/ulnar deviation, circumductions
Which has more movement, radial or ulnar deviation? ULNAR
Ligaments of the wrist Flexor retinaculum, extensor retinaculum, collateral lig., radiocarpal lig., ulnocarpal lig., intercarpal lig.
True or False: Since the wrist is a hinge joint, it has the same limited movement as other hinge joints such as the knee. FALSE: it has more movement
Collateral Ligaments usually found at hinge joints
Collateral ligaments of the wrist radial and ulnar collateral ligaments and run from each bones' styloid processes to the carpals
Function of collateral ligaments_ prevents excessive deviation of the wrist.
Deep palmar ligaments palmar radiocarpal lig., palmar ulnocarpal lig., prevents hyperEXTENSION of the wrist
During supination of the hand, the _________ligament tightens radiocarpal
What ligaments are most frequently injured when you fall? palmar ligaments
Deep Dorsal ligaments dorsal radiocarpal, dorsal ulnocarpal, prevent hyperFLEXION of the wrist
When the wrist is in pronation, what ligament is the tightest? dorsal radiocarpal lig.
Intercarpal ligaments bind together adjacent carpal bones to maintain stability of the wrist
Fractures of the wrist Colle's (radius), Smith's (radius), scaphoid, lunate dislocation (palmar)
In a Colle's fracture______ the wrist hyperEXTENDS and the fractured fragment moves dorsally
In a Smith's fracture______ the wrist hyperFLEXES and the fractures fragment moves palmarly
Also called a dinner fork fracture: Colle's fracture
This fracture usually coincides with a Colle's fracture. Scaphoid, usually at its narrow center. Can lead to necrosis in the upper half of the bone and must be surgically removed
Lunate dislocation the lunate "pops" out of position in a hyperFLEXION injury. The ligament tears, causing an anterior dislocation into the carpal tunnel. If both ligaments tear, it can lead to necrosis and must be surgically removed
Joints of the fingers: CM, MP (ball & socket), PIP (hinge), DIP (hinge), IP
Which joint of the hand is a saddle-shape? Between the trapezium and MC1 (thumb)
The saddle shaped joint allows the thumb the ability to oppose
Motions of the thumb extension, flexion, abduction, adduction, opposition, reposition
Extension of the thumb hitch-hiking
Flexion of the thumb Thumb across palm
abduction of the thumb thumb away from palm in plane of the index finger
adduction of the thumb thumb toward the base of the index finger
Opposition of the thumb pads of thumb and finger come together
Reposition of thumb moves thumb back to anatomical position
Motions of the metacarpals MC1: highly mobile, MC2 & 3: fixed, MC4: slight opposition, MC5: moderate opposition
Structural center of the hand MC 2 &3
Ligaments of the fingers carpometacarpal, (inter)metacarpal, palmar, and collateral
Carpometacarpal ligaments at palmar and dorsal CM joints
Intermetacarpal ligaments between MC bases
Palmar ligaments at MP & IP joints
Collateral ligaments fan-like at volar plates, cord-like into bone
MP collateral lig. Tightest in FLEXION, preventing abduction in power grip
PIP and DIP collateral lig. tightest in EXTENSION, prevents collapse when using finger as a probe
Fracture of the finger Boxer's fracture (MC4 or 5)
What is Boxer's fracture? When MC 4 and/or 5 hit something off center and are fractured, bones will heal curved toward the palmar side of hand, and there will be no nerve damage
Intrinsic muscles of the hand arise . . . from within the hand, but do NOT cross the wrist
Intrinsic muscles of the hand - GROUPS Thenar, hypothenar, lumbricals, interossei
How many thenar muscles are there and what are their names? 4: ABductor pollicus brevis, opponens pollicus, flexor pollicus brevis, ADductor pollicus
The thenar muscles form the ________, are responsible for _______, and are innervated by________ thenar eminence, movement of the thumb, both ulnar and median nerves
The hyporthenar muscles form the _______, are responsible for ______ and ________, and are innervated by the ___________. hypothenar eminence, moving the pinkie and corrugating the skin over the eminence, ulnar nerve
How many hypothenar muscles are there, and what are their names? 4; palmaris brevis, ABductor digiti minimi, flexor digiti minimi, opponens digiti minimi
Palmaris brevis functions corrugates the skin, but does NOT move the pinkie
Substitute for ADductor in hyporthenar eminence palmaris brevis
Lumbrical attachments O: FDP tendons; I: extensor hoods on RADIAL sides of digits 2-5
Lumbrical functions Flex MP joints and Extend IP joints
Lumbrical Innervation #'s 1 and 2 - MEDIAN; #'s 3 and 4 - ULNAR
What dance do the lumbricals allow you to do (in part) the chicken dance (chicken hands!)
How many interossei muscles are there? 7 that are divided into two groups
Palmar interossei attachments O: MC shafts facing the middle digit; I: extensor hood phalanges
Palmar inerossei functions ADduct digits 2,4, and 5, EXTENDS IP joints
What muscle is responsible for ADduction of the thumb? adductor pollicus
The middle finger only ________ ABducts because it is the "midline" of the had
Dorsal interossei muscle attachments O: MC shafts; I: extensor hoods
Dorsal interossei functions ABduct digits 2, 3, and 4, assist in extension of IP joints
Which digit has 2 dorsal interossei muscles and why? the middle finger (digit 3) because it can only ABduct !
Innervation of dorsal interossei ULNAR n.
If you damage your Ulnar nerve, how is your hand effected? loss of fine motor movements
Summary of intrinsic hand innervartion thenar- ulnar and median, hypothenar- ulnar, lumbricals- median, interossei- ulnar
What muscle can be considered an honorary dorsal interossei? abductor digiti minimi
What muscles are closest to the extensor hood? interosseus
Which muscle is more powerful in flexing the MP joint? Lumbicals
On the dorsal side of the hand, the extensor digitorum tendon splits into ______, that are called__________ 3 slips, central (inserts into mid. phalanx) and 2 lateral (inserts into distal phalanx)
On the palmar side, what 2 muscles control flexion flexor digitorum superficialis(mid. phalanx) and flexor digitorum profundus (distal phalanx)
Fibrous digital sheaths are : long tubular ligaments, surrond the long flexor tendons and synovial sheaths, composed of annular and cruciate ligments
Where are the fibrous digital sheaths located? palmar side of fingers
Which is stronger, annular or cruciate ligaments? annular
What does the fibrous digital sheath prevent? Bowstringing of the flexor digitorum superficialis and profundus during flexion
Created by: CoachAmy



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