lecture 6: biomecs of the foot and ankle Flashcards
what are th ebones of the lower leg
tibia
fibula
what two bones form the ankle mortise
tibia and fibula
the tibia and fibila create what projections at the ankle
medial and lateral malleolus
whta is the mortise
U shaped to allow the talus
wht bones of the foot make uo the hindfit
talus
calcaneus
what bones make up the midfootq
navicualr (medial), cuboid and cuneiform (3x)
what bones make up the forefoot
metarsal and phalanges
bulk of ankle motion causes at what part of the foot
hind foot
what sits in the mortise
hindfoot
what are the 3 joints of the ankle/foot
ankle (talocrural)
subtalar
distal tibiofibular (syndesmosis)
what are the bone articulations of the talocrural joint
tibia/fibula with talus
what are the bone articulations of the subtalar joint
talus with calcaenus
what are the bone articulations of the distal tibiofibular joint
tibia with fibula (stabilizing joint)
what is the foot motion in the sagital plane
dorsiflex/plantar flexion (sometimes called flexion/extension
what is the foot motion in the frontal plane
eversion/inversion
what is the foot motion in the transveres plane
abduction/adduction
true or false: eversion and inversion of the foot occurs in the transverse plane
false, frontal
eversion/inversion of the foot is sometimes called wjat
supination/pronation or aductoon./abdctuon
abduction/addiction is sometimes called wat
internal/external rotation or varus/valgus
true or false: the axis of movement in the foot do not line up with cardinal planes
true, therefore triplanar motion
what does it mean that the anle has triplanar motion
can move in all three planes at the same time
what is suppination a combo of
plantarflexion,
inversion
adduction
plantarflexion,
inversion
adduction
is associated with pronation or supination
supination
what is pronation a combo of
dorsiflex
eversion
abduction
dorsiflex
eversion
abduction
is assocaition with pronation or supination
pronation
supination is associated with a rigid or flexible foot
rigit
pronation is associated with a rigid or flexible foot
flexible
supination causes eleveation or lowering of the medial long arch
rigid foot
elevation of medial long arch
pronation causes eleveation or lowering of the medial long arch
lowering
flexible foot
true or false: tibia rotations are not coupled with foot movements
false
tibia internal rotation is assocaited with foot pronation or supination
foot pronation (eversion and abduction)
tibia external rotation is assocaited with foot pronation or supination
supination (inversion, adduction)
why is it importance that the tibia rotation are coupled with foot movements
helps transmit force effectively (even dispersion of forces)
what type of joint is the ankle/ talocrural joint
hinge
how many degrees of freedom in the talocrural joint
1 or 6 (because triplanar)
what is the movement at the talocrural joint
dorsiflexion
plantarflexion
what is the axis of the talocrural joint
axis runs (from medial side) lateral, inferior and ppsterior
might move during movement
area of contact in the talocrural joint increases or decreases with incrasing force and why
area of contact increases with increasing force (helps distribute stress)
in dorsi flexion, the contact area moves anterior and the tibia translates BLANK wrt to talus
anterior
in dorsi flexion, the contact area moves anterior and the talus translates BLANK wrt to tibia
posterior
in plantar flexion, the contact area moves posterior and the tibia translates BLANK wrt to talus
posterior
in plantar flexion, the contact area moves posterior and the talus translates BLANK wrt to tibia
anterior
subtalar joint invovles what two bones
talus and calcaneous
what is the function of the subtalar joint
translate motion between foot and tibia (walk on uneven ground, pivot)
what type of joint is the subtalar joint
hinge (mitered) or multi axial ???
what is the axis of the subtail joint
from medial side, runs lateral posterior and inferior
what are the movements possible at the subtalar joint
inversion/eversion
abduction/adduction
how does oatis 2009 describe the subtalar joint
hinge or mitered hintge
how does maceira 2015 describe subtalar joint
anterior/middle = ovoid/bean or two seperate
posterior = talus is concave, calcaneous convex
anterior - talus is convex, calcaneous is concave
how does jastifier 2014 describe the subtalar joint
posterior - talus is concave, calcaenous convex
anterior - talus is convex, calcenous is concave
mitered hinge
can not be described AS A SIMPLE MACHIEN
whst is the max range for dorsiflexion
10-20
whst is the max range for plantarflex
35-55
whst is the max range for inversion (with adduction)
20-30
whst is the max range for eversion (with abduction)
4-28
how do midfoot and forefoot contribute to the entire motion
contribute to the entire motion of the foot in all planes
understand the sagital angle ankle graph
.
does the ankle start in dorsiflexion or plantar and why
dorsi flexion to clear the ground
why does the sagital angle get closer to plantar flexion from 0-20 degrres
starts in dorsiflexion to clear the ground but becomes more plantar for full ground contact
why does the foot dorsi angle increase from 20-50 degrres
foot is fixed in closed chain dorsiflexion
why is there a steep decrease in dorsi (incrase in planar flexion) from 40-60
pushing off (toe off) to start the swing phase
why does dorsiflexion incrase after toe off
dorsi flexo to clear foot and prepare for ground cotnact
understanf the frontal angle graph for the anklr
.
why does eversion (with pronation) icnrease during increased ground contact
want more pronation (flexible foot) when youre hitting the grounf to absorpt shock
as you get closer yo toe off, do you want more inversion or eversion
more inversion (and supination) for a rigid foot to propel forward
where is there greatest pressure points on the foot
heel and ball of foot
greatest pressure on the 2nd metatarsal
true ro false, greates pressure on 1st metatarsal
false, second
what is the function of lateral colalteral lig
resist inversion/varus stress
what is the function of the medial collateral lig (deltoid)
resist eversion/valgus stress
true or false: lateral collateral lig strain is more commen
true
true or false: medial collateral lig protects against inversion/varus stress
false, eversion and valgus
what are the components of the medial longitudinal arch
calcaneous, talus, navicular, medial cuneiform and 1st metatarsal
what are the compoents of the lateral long arch
calcanous, cuboid and 5th metatarsal
what are the compoents of teh tranverse arch
cuboid, cuneiforms and metarsals
what are the 3 functions of the foot arches
protect nerves, vessels, and muscles on plantar surface
absrob shock
release stored energy
what gives support to the arches
boney shape
ligaments
msucles
plantar fasica
why does arch height decrease from 0-50% of gait cycle
arch length dropping goes with pronation
allows for shock absorption (during ground contact)
why does arch height increase from 60% of gait cycle
arch length increases, more supination and a rigid foot needed for propulsion
what is a high medial long arch called
pes cavus
what is a flat foot, low med long arch called
pes planus
what is pes cavus
high medial long arch
what is pes planus
flat foot, low med long arch
what is the issue with pes cavus (hgih med long arch)
rigid foot
less able to absorb shock
you are less able to absoprt shock with pes planus or cavus
cavus
what is the issue with pes planus (flat foot, low med long arch)
mobile foot, more able to attenuate shock but higher demand of soft tissue to support arch
with pes cavus where are the highest peak pressures
higher peak pressure on the 1st, 4th and 5th metarsal and lateral heel
true or false: in pes cavus there is higher peak pressure on the 1st, 2nnd and 5th metarsal and lateral heel
false, not second, but 4th
with pes planus, where is there higher peak pressure
higher peak pressures on hallux and 2nd toe
according to oatis, is there a clear injury pattern based on foot type
no
according to menz et al, pes planus or cavus is assocaited with arch pain
pes planus
according to dixon 2019, military recreuits with high arch had what injuries
assocaited with 2nd metatarsal stress fractures
according to williams and el, in runners iwth a high arch, what are common injuries
stress fracture 5th metatarsal, increased boney injurie
according to williams and el, in runners iwth a low arch, what are common injuries
more soft tissue injuries (tendinitus) stress fractures in 2 or 3 metatarsal
according to the vertical GRF and % stance graph, those with a high arch looked like what in the graph
higher arch have greater load/GRF (less ability to absorb shock)
according to the vertical GRF and % stance graph, what was the corrleation with rate = force/time
lower arch people have lower GRF and lower loading rate
where does the plantar fascia attache
attaches from calcaneous tuberosity to metatarsal, phalanges and ligaments
plantar fascia may be stretched with low or high arch
low arch
plantar fasica has great BLANK stress
tensile
what is the function of the plantar fascia
arch support
windlass effect
what is the windlass effect
supinated (rigid) foot during push off
1st toe (big) extends and streches the plantar fascia
plantar fascia supportsd arch (passive stability)
wht is plantar fascitis
inflammation where plantar fascia attaches to the calcaneous
what are the symptoms of plantar fasicits
pain in the medial heel
worse in morning, first few steps
wht are the risk factors for plantar fascitis
non athletes: body mass index?, arch height?
athletes: lower med long arch (increased stress on plantar fascia)
motion control shoes are used for what type of arch
low arch (pronated)
low arches are pronated or supianted
pronated
in a motion control show, is there stiffer or more flexible material in sole
stiffer
what is medial posting in motion control sjoes
denser material to prevent pronation
cushion shoes are for high or low arch
high arch (supinated)
high arches are supinated or pronated
supinated
in cushion shoes, are there stiffer or flexible soles
more flexible
do cushion does have medial posting
no
what were the results of the study between motion control vs cushion shoes
motion control sjoes prevented injury but more in runners with pronated feet
what type of foot strike is recommended for running
forefoot strike running is recommended
what is the problem with rearfoot strike during running
increase in loads/rate of loading
lead to more injuries
why is rear foot strike not recommeded for running
increases the vertical GRF faster than midfoot
what do minimalist shoes allow
allow foot to absorb loads, not the shoes
what is the hypothesis for minilist shoes
encourage midfoot landing which reduces ground reaction force compared to tradiotional shoes
why is there controversy if minimalist shoes decrease injury
increase in injury and or pain with minimalist footwear for new users
(same training but removing what your body is used to)
true or false: minimalist shoes showed no difference in ankle hip and knee angles and moments
true
there is an icnrease in vertical loading rate with minimalist shoes in novice or pro users
novice
what muscles form the achilles tendon
gastroc and soleus (plantarflexors)
true or false, the achilies tendon has a large plantar flexion moment
yes there is an icnreased leverage because of the calcaneous
when does the achilies tend to rupture more and why
more frequent in middle aged
=less active, decreased blood flow, increased stiffness, decreased collagen strength
what is the strongest dorsiflexor
tibialis anterior
what are the dorsiflexors supplied by
deep peroneal nerve
weakness in tib ant leads to what
foot drop (need dorsiflex to prevent tripping over foot)
how can you get foot drop
damage to peroneal nerve (fibular fracture surgery)
central nervous condition (ex: stroke)
what is the treatment for foot drop
ankle foot orthosis
electrical muscle stim
understand the stroke graph about the sagital ankle angle
