Muscles, actions, and corresponding cord segments Flashcards
What’s the nerve to levator scap?
dorsal scapular
- also supplies rhomboids
If the long thoracic muscle is cut with a surgery, what muscle(s) will be damaged?
serratus anterior
Do the rhomboids do upward or downward shoulder rotation?
downward (serratus and upper trap do upward)
What muscles do scapular downward rotation?
pec minor, levator scapula, and rhomboids
What muscles do lateral rotation?
infra
teres minor
What are the roles of levator scapula? What cord segment corresponds?
scapular downward rotation and elevation
C5
What muscles do shoulder abduction?
supraspinatus and deltoid
What are the roles of pec major and minor, and what cord segment and nerve correspond?
horizontal adduction of shoulder
- C5-8 and T1
- medial/lateral pectoral n.
Medial pectoral nerve innervates what pec(s)?
medial does both
lateral just does pec major
What muscle innervates supraspinatus? Infraspinatus? What are the corresponding cord segments?
supra and infra are both innervated by suprascapular (C4-6)
What does axillary nerve innervate?
deltoid and teres minor
Which rotator cuff muscle is innervated by axillary nerve?
teres minor
What does musculocutaneous nerve innervate? (3)
biceps brachii, coracobrachialis, brachialis
What is the C6 myotome?
biceps
What is the C5 myotome?
shoulder abduction
What is the C4 myotome?
shoulder shrug
What are the actions of pec minor? It’s innervation? Corresponding cord segments?
shoulder horizontal adduction, downward rotation
- nerve = medial pectoral
- cord = C8-T1
Name the four superficial muscles of the anterior forearm.
1) pronator teres
2) flexor carpi radialis
3) palmaris longus
4) flexor carpi ulnaris
How many muscles are in the anterior forearm?
8 (4 superficial, 1 middle, 3 deep)
What is the middle-layer muscle in the anterior forearm?
flexor digitorum superficialis (attaching to PIP)
What are the 3 deep muscles of the forearm?
1) flexor digitorum profundus
2) flexor pollicus longus
3) pronator quadratus
What are the anterior muscles of the forearm innervated by?
all except FCU and ulnar half of profundus are median
- FCU and ulnar half of profundus is ulnar n.
What are the hand muscles innervated by?
1/2 LOAF = median
- 2nd and 3rd lumbricals
- opponens, abductor, and flexor hallicus
ALL else ulnar
What are the PADs and DABs of the hand innervated by?
ulnar
PADs = palmar adductors DABs = dorsal abductors
How many muscles are on the posterior arm?
12 (6 superficial, 6 deep)
What does brachioradialis do?
flexion of the elbow in pronation position
pronation
What are the 6 superficial muscles of the posterior forearm? (hint: remember the numbers)
brachioradialis
extensor carpi radialis longus
extensor carpi radialis brevis
4) extensor digitorum (to all four fingers)
5) extensor digiti minimi (to pinky finger)
extensor carpi ulnaris
What muscle that flexes the elbow is found on the posterior forearm?
brachioradialis (C5-6), radial n.
What are the 6 deep muscles of the posterior forearm? (hint: running down the arm)
anconeus
supinator
*snuff box: APL, EPB, EPL,
extensor indices
What innervates the lumbricals?
ulnar half = ulnar
radial half = radial
What muscles do forearm pronation?
pronator teres
pronator quadratus
- both median, C6-7
What muscles do thumb extension?
EPL/EPB (part of snuff box)
What ligaments reinforce the AC joint?
coracoacromial lig (not true ligament, since it’s same bone -> same bone)
coracoclavicular lig - trapezoid, conoid
What ligaments help reinforce the glenohumeral joint?
glenohumeral ligaments (superior, middle, inferior)
What’s the purpose of the coracohumeral ligament?
reinforce biceps tendon, reinforce superior capsule, prevent caudal dislocation
What ligament supporting the AC joint is most important, because when that’s torn, usually the AC comes apart?
coracoclavicular
What muscle is the glenoid labrum attached to?
superiorly is attached to long tendon of the biceps brachaii
What bursae is most commonly implicated in pathology of the shoulder?
subacromial (lies right above supraspinatus, right below acromion)
What motion has to occur at the GH joint so that compression of the greater tubercle on the acromion doesn’t occur?
ER at 75deg of elevation
Your patient isn’t able to achieve full shoulder elevation. What events should you look for to make sure they’re occuring? (6: hint - think shoulder motions but also beyond just shoulder joint)
- effective inferior glide of humerus
- scapular stabilization
- ER of humerus
- posterior rotation of clavicle
- scapular abduction and lateral rotation of AC
- straightening of thoracic kyphosis
The trochlear notch is on what bone?
ulna
- trochlea is on distal humerus
Where is the capitulum?
distal radius, articulates with head of radius
What ligaments reinforce the proximal elbow joint?
lateral collateral ligament
medial collateral ligament
annular ligament
Your patient is having difficulty with pushups, noting pain at the elbow with descent. What motions might you check to ensure arthrokinematics are occuring?
closed chain elbow flexion: convex on concave
- anterior roll with posterior slide needs to occur
What’s the screw home mechanism for the elbow?
slight internal rotation (pronation) of ulna with extension
slight ER with flexion
What are the bones of the hand in the proximal row, listing from laterally to medially?
some - scaphoid
lovers - lunate
try - triquetrum
positions - pisiform
List the distal row of carpal bones, laterally to medially.
that - trapezium
they - trapezoid
can’t - capitate
handle - hamate
Is the ulna convex or concave at the distal end?
convex
- radius is biconcave
What is the thumb joint called? Describe its articular surfaces.
CMC - carpometacarpal joint trapezium on metacarpal
- trapezium is convex in medial/lateral direction, while it’s concave in anterior/posterior direction
With abduction of the thumb, what direction are the rolls and slides?
roll and slide in opposite directions convex metacarpal on concave thumb
With flexion of the thumb, what direction are the roll and slide?
roll and slide in SAME direction
If a patient is lacking flexion of the CMC joint, what direction should you mobilize?
mobilize metacarpal in medial direction (following flexion)
- since rolls and slides are in the same direction
What is a slide in the volar direction?
palmar slide
When mobilizing for a patient that’s lacking CMC abduction, what direction should you mobilize?
dorsal slide (since roll and slide are in opposite directions)
When are the volar plates of the fingers taut?
volar plates are on palmar aspect of MCP/PIP/DIP joints
- taught in extension -> prevent hyperextension
What is the purpose of the extensor hood?
fibrous expansion of each extensor digitorum tendon
- assists with PIP/DIP extension (but remember it’s non-contractile)
What nerve innervates the thenar eminence?
ulnar
During opposition, what motion must happen with the metacarpal?
ulnar rotation
What kind of glide do you need to achieve wrist flexion?
dorsal glide of scaphoid and lunate
- so volar glide for ext.
What kind of glide must occur for radial deviation?
ulnar glide of proximal row
Angle of inclination at the femur is typically what?
115-125deg
Greater than 125deg of inclination at the femur is called what?
coxa valga
- coxa vara is <115deg
What’s the typical anteversion angle of the hip? What angles are considered excessive anteversion or retroversion?
typical anteversion: 10-15deg
- excessive anteversion is > 25-30deg
- retroversion is <10deg anteverted
What ligaments reinforce the hip joint?
iliofemoral (Y) = prevents extension and ER
ischiofemoral = prevents IR, abd, extension
pubofemoral = prevents extension, ER, abd.
What attachments does the inguinal ligament have?
runs from AASIS to pubic tubercle
- forms a tunnel for muscles, arteries, veins, and nerves
What is the L2 dermatome? Muscles tested?
hip flexion; iliopsoas and sartorius
What muscles do hip external rotation?
piriformis, quadratus femoris, gemelli, obturator internus, glute max
What actions does glute med do?
anterior: hip flexion/IR
posterior part: hip extension/ER
Both parts do abduction
What does obturator internus do?
ER, extension, abduction of hip
What does obturator externus do?
ER and adduction of hip
What muscle does ankle inversion and what it it innervated by?
tib posterior -> tibial n.
What does sciatic nerve branch into?
branches into common fib and tib nerves at the popliteal space
What nerve innervates the adductors? (and list adductors)
obturator n.
- adductor magnus/longus/brevis
- pectineus
- gracilis
What muscle does lower leg medial rotation to unlock knee?
popliteus
What nerve supplies control to pelvic floor?
pudendal n.
What muscles get innervation from sciatic?
semitendonosis/membranosis
How would you stretch the TFL? What’s its innervation?
hip extension, ER, and adduction
- since it does HF, IR, Abd
- innervated by superior gluteal n.
What does superior gluteal n. innervate?
glute max and TFL
What’s the L4 myotome? What nerve is being tested?
dorsiflexion (deep fib innervation)
If a patient has poor PF, what nerve could be implicated?
tibial
What nerves cause toe flexion/ext.?
medial/lateral plantar nerves (branch off of tibial)
EDL and EHL are innervated by what?
deep fibular (same as anterior tib) -> L4-S1
What is L5 myotome testing, muscle and nerve?
extensor hallicus longus, deep fibular n.
What is the S1 myotome?
foot inversion/eversion (but we learned PF)
Are knee MCL and LCL ligaments taut in extension or flexion?
extension
What ligament is taut with valgus force to the knee?
MCL
- also prevents ER of knee
T/F: Medial collateral ligament of knee blends with the capsule.
true
T/F: LCL of knee prevents knee ER and provides stability against varus forces.
true
What motion does the ACL prevent?
excessive anterior translation of tibia on femur
- also limits IR of tibia during flexion
What muscle augments PCL function?
PCL prevents posterior translation of tibia on femur
- so muscles that do knee extension augment PCL = quads
The oblique popliteal ligament inserts onto what muscle’s tendon?
semimembranosus
- it also partially blends with capsule
What muscles insert onto pes anserine?
S - sartorius
G - gracilis
T - semitendonosis
Where does the acuate popliteal ligament attach to?
it’s lateral: attaches from lateral fem. condyle to fibular head, strengthening the posterolateral capsule
What does the medial meniscus attach to medially?
MCL and fibrous capsule
- semimembranosis and medial meniscopatellar ligament also
What roles does your meniscus play?
shock absorption improve congruency at joint provide stability to joint reduce friction during movement improves weight distribution
What structures attach to lateral meniscus?
popliteus
When walking, what is the typical ROM of knee flexion?
15deg
What is the screw home mechanism of the tibia/femur when in closed chain?
- closed chain: when walking, femur internally rotates to lock knee for more stability
- open chain: tibia ERs about 5deg
With DF of talocrural joint, what motion occurs at the proximal tibfib joint?
fib head glides superiorly and posteriorly
- glides inferiorly and anteriorly for plantarflexion
If a patient is having difficulty with DF, what motion could you manipulate their fibular head?
superior/posterior
What three things make up the talocrural joint?
medial malleolus of tibia
lateral malleolus of fibula
trochlear surface of talus
Why do you MWM at the ankle in the way you do? (think OSU sports clinical, give arthrokinematic reason)
in weightbearing, concave surface of tibia is moving on convex surface of fibula
- so an anterior slide of tibia has to occur; by holding down talus and pushing posteriorly, you’re allowing this anterior slide
Where is the cuboid in the foot?
lateral, proximal to 5th metatarsal
Where are the cuneiforms in the foot?
beginning medially, just distal to 1st through 3rd metatarsals
What does the talus articulate with?
with the calcaneus (inferiorly) and the navicular (distal to talus, on medial side of foot)
talus -> navicular -> cuneiforms -> 1st three metatarsals
What does the calcaneus articulate with?
talus (superiorly)
cuboid (distally, on lateral side of foot)
calcaneus -> cuboid -> 5th met
What bone is the key to the lateral arch?
cuboid
What does the calcaneal tilt test check for?
excessive motion at calcaneofibular ligament
What is the spring ligament?
calcaneonavicular ligament
When is the plantaraponeurosis at maximal tightness?
windlass effect: DF of MTP joint
- causes supination of calcaneus and inversion of subtalar joint, creating a rigid lever for push off
What foot position results from the windlass effect?
calcaneal supination, inversion of subtalar joint
What do the uncinate joints limit, motion wise?
limit lateral cervical flexion at C3-7
What is the rule of 3?
- TP of T1-3 are even with the SP of same level
- TP of T4-6 are found 1/2 level above SP of same level
- TP of T7-9 are one full level above SP of same level
To locate the TP of T9, how would you palpate to do this?
go one level up to T8 SP and then laterally for T9’s TP
Where are the TP of T10-12 located?
TP of…
- T10 = one level up (T9)
- T11 = one half level up (between T10 and T11)
- T12 = level with T12
What is the joint that performs the “no” head motion?
atlanto-axial joint (AA)
- dens of C2 and anterior arch of C1
- most of head rotation comes from this joint
What’s the difference between the AO and AA joints?
AO = occiput and C1 (yes joint) AA = C1 and C2 (no joint)
Describe the anatomy of a disc.
annulus fibrosis = collagen and fibrocartilage, 65% H20O
Nucleus pulposis = gel
- vertebral endplate provides nutrients
What nerves are involved with inspriation?
phrenic
intercostal
What comes first in the spine, the root or the rami?
ventral and dorsal roots off of spinal cord -> join to become spinal nerve -> divide into ventral/dorsal rami
If a patient rotates to the R, are they gapping or approximating their R L4/5 facet joint?
gapping ipsilaterally
approximating contralaterally
so, they’re gapping
When you rotate R, what coupling motion happens at C2-7?
side bending to R
- coupling of side bend and rotation from C2-7
OPPOSITE for occiput and C1: occiput sidebends, C1 rotates in opposite direction
With a patient who can’t rotate their neck fully to the R, what may not be happening at their facet joints that should be?
R superior facets should be moving posteriorly and inferiorly
- also, recall that in C-spine, rotation causes approximation ipsilaterally (converse in lumbar/thoracic spine)
What coupling occurs in lumbar spine (neutral spine vs flexion spine)?
neutral: lumbar segments will side bend and rotate in opposite directions (ex. side bend R will result in segment rotating L)
Flexion: they move together
What is nutation?
flexion of sacrum and posterior counter-rotation of ilium
If the sacrum is stuck in extension, it’s said to be stuck in what position?
counternutation
- sacrum extended, ilium anteriorly rotated
T/F: TMJ articular surfaces are covered with hyaline cartilage.
false, covered with dense fibrous connective tissue
What’s the functional range of opening of the TMJ?
40mm
