MSK foot and ankle Flashcards
how many bone are in the foot and ankle?
28
what is the shank?
the tibia and fibula
medially rotated the rearfoot with pronation
syndesmotic joint
how much of body weight goes through the tibia?
70-90%
what is the mortise?
space created by tibia and fibula where talus articulates
very important for stability
open chain DF vs closed chain DF glides at the mortise
open chain: talus glides posterior on a fixed tibia
used post glide
closed chain: tibia glides anterior on a fixed talus
use ant glide
describe the talocrural joint
artic of the talus and mortise
primary function is PF and DF
wedge shape
greater stability in DF
what muscles attach on the talus?
none
what does the interosseous ligament do?
transfers some WB force to the fibula
injured with rotation
what do the tibiofibular ligaments do?
prevent excessive displacement of the fibula
what is the deltoid ligament for?
restrains eversion
what are the ant/post talofibular and calcaneofibular ligaments for?
restrain inversion
describe the subtalar joint
artic of talus and calcaneus
“bridge between the foot and ankle”
mobile yet stable
mvmts of supination and pronation
what is the sinus tarsi?
area of nerves for proprioception
between the two artics of the subtalar joint
what are the two subtalar joint axis?
superior view: 23 deg +/- 11 (towards big toe)
medial view: 41 deg +/- 9 (anterior is up)
midtarsal joint
chopart joint
talonavicular is more mobile
calcaneocuboid
mvmts of eversion/inversion and PF/DF
tarsometatarsal joint
lisfranc joint
cuneiforms and MT 1-3, cuboid and MT 4-5
very little motion in 1-3 (like the hand)
lisfranc injury most common at 3 MT
where is the lisfranc ligament?
medial cuneiform to 2 MT
1st MTP joint
transmits lots of force
80% during walking
200% during athletic activities
800% during jumping
where are the two sesamoids of the foot?
near 1st MTP
how much mobility is needed at 1st MTP?
60-75 deg
describe the plantar fascia
type I collagen
prevents collapse of longitudinal arch
when is tension in plantar fascia highest?
between initial contact and loading response
what are some potential causes of heel pain?
subcutaneous calcaneal bursa - tight shoes
retrocalcaneal bursa - between achilles/calc
calcaneal fat pad - 2nd leading cause
what are the muscles of the anterior compartment?
anterior tibialis:
primary DF/inverter in OC
stab talocrural and midfoot in CC
extensor hallucis longus:
extends great toe and stab midfoot
extensor digitorum longus:
extends 2-5 and stab midfoot
peroneus tertius:
assists in DF/eversion
synergist with per brevis
what is the innervation of the anterior compartment?
deep peroneal nerve
what is the extensor retinaculum for?
hold tendons close to join so they cant get away because there is not a straight line of pull
superior and inferior
what muscles are part of the superficial posterior compartment?
gastroc
soleus
plantaris
innervated by tibial nerve
PF, stab foot through plantar fascia
what muscles are part of the deep posterior compartment?
tibialis posterior - PF, inv, stab arch
flexor digitorum longus
flexor hallucis longus
innervated by tibial nerve
FDL/FHL stab foot and provide proprio
what is the windlass mechanism?
plantar fascia attaches to MT, phal, flexor tendons
passive extension at 1st MTP tenses plantar fascia to move foot from pronation into supination and provide a rigid lever for push off
describe the flexor retinaculum
from med mall to calc
roof of the tarsal tunnel
contributes to tarsal tunnel syndrome
prevents tendons form rolling over the mall
what is housed in the tarsal tunnel?
post tib
FDL
FHL
post tib vein/artery
tibial nerve
what are the muscles in the lateral compartment?
fibularis peroneus:
distal attachment to medial cuneiform and base of 1st MT
imp for proprio
PF and ever
stabilized medial foot
fibularis brevis:
primary evertor of rearfoot
resists inversion
fibular retinaculum
prevents sublux of tendons
vulnerable during inversions strains
inferior is continuation of extensor ret
what nerve innervated the foot intrinsics?
plantar: med and lat plantar nerves
dorsal: deep fibular
what do the foot intrinsics do?
support longitudinal and transverse arches
describe the tibial nerve
motor and sensory
branches into med and lat plantar nerves
PF and flex toes
MPN: abd hall, FDB, FHB, first lumbrical
LPN: QP, FDM, add hall, lat lumbricals, interossei, abd DM
interdigital (morton’s) neuroma
plantar branches irritated
between 2&3 or 3&4
describe the fibular nerve and branches
superficial:
PL, PB - lateral muscles
deep: ant tib, EHL, EDL, dorsal foot intrinsics
anterior muscles
lisfrac area
sural nerve:
sensory for lat heel, foot and ankle
entrapment
foot and ankle ability measure
21 ADL and 8 sports items
MCID = 8
less opportunity for ceiling effect
is the pain pattern of ankle reliable?
very
which nerve entrapment site is commonly misdiagnosed as plantar fascitis?
baxter’s nerve entrapment
one medial foot
what is the foot posture index 6 for?
to determine if foot is pronated (>4) or supinated (<0)
symptoms of compartment syndrome?
95% in ant or lat compartments
cramping, burning, numbness
has a predictable pattern
ottawa ankle rules
ANKLE: pain in malleolar zone plus one of following
- tenderness of lat mall
- tenderness of med mall
- inability to bear weight for 4 steps immediately after injury and at time of eval
FOOT: pain in midfoot plus one of following
- tender base of 5th MT
- tenderness of navicular
- inability to bear weight for 4 steps immediately after injury and at time of eval
tuning fork exam
TESTING FOR: bone injury (fracture)
place vibrating tuning fork on area of suspected fracture
test BILATERALLY
+ if symptoms reproduced
thompson test
TESTING FOR: achilles rupture
pt prone
squeeze calf muscle
+ ankle remains still or only minimal PF occurs
how can you clear the lumbar spine and hip?
quadrant test
MRS
neurodynamics
ROM with overpressure
what % of referral pain goes past the knee?
10%
neurodynamics: TED
tibial nerve bias
perform straight leg raise
evert and DF the foot
neurodynamics: SID
sural nerve bias
perform SLR
invert and DF to foot
