Ankle & Foot Flashcards
static & dynamic functions of foot and ankle
- support base for upright posture w/ minimal effort
- transition of mobile adaptor (absorb shock) to rigid lever (impart thrust)
- sensory / proprioceptive function
Ankle Contents (bones & joints)
Bone: tibia, fibula, talus
Joint: talocrural, proximal and distal tibiofibular
Rearfoot contents (bone and joints)
bone: calcaneus & talus
joint: subtalar (talocalcaneal)
Midfoot contents (bone & joints)
Bone: navicular, cuboid, cuneiforms
Joint: transverse tarsal, distal intertarsal
Forefoot (bone & joints)
Bone: metatarsal and phalangeal
Joint: TMT, InterMT, MTP, IP
fibula osteology
(proximal fibular & lateral malleolus)
- comprises lateral ankle
- attachment side for ligament
- implicated in fractures .
tibia osteology
expanded size distally to accommodate load
- medial malleolus
- fibular notch
Ankle Mortis of Talus
when you DF, the talus moves back into this joint & causes the tib & fib to seperate
Open Kinetic Chain Motions of Ankle & Foot
PF & DF
Inversion & Eversion
Closed Kinetic Chain motions of ankle & foot
squatting = DF
walking downhill/stepping/heel raises = PF
PF & DF axis and plane of motion
medial - lateral axis
sagittal plane
Inversion & Eversion axis and plane of motion
anterior-posterior axis
frontal plane
abduction and adduction axis and plane of motion
vertical axis
horizontal plane
oblique axis of rotation
triplanar motion
supination axis and plane of motion
oblique axis
plane: inversion, ADD, PF
pronation axis & plane of motion
oblique axis
plane: eversion, ABD, DF
DF ROM
10-20 degree
PF ROM
30-50 degree
Eversion/Inversion ROM
approx 40 degree
what is inversion limited by
subtalar interosseous ligament (stabilized supinated foot)
what is eversion limited by
eversion limited by bony obstruction on both side
Proximal Tib-Fib Ankle joint
- synovial joint
- articulation b/w head of fibula and posterolateral lateral condyle of tibia
- stabilization of anterior and posterior ligaments
Distal Tib-Fib Ankle Joint
- syndesmotic joint
- articulation b/w convex medial fibula and concave fibular notch on tibia
- stabilization of interosseous membrane, anterior and posterior tibiofibular ligaments
anterior and posterior tibiofibular notch
- stabilizer to splaying of ankle mortise during DF
- limits ER
- limits fibular mobility on tibia
interosseous membrane
- force dissipation
- stabilizer of splaying of ankle mortise
Talocrural Joint
- synovial hinge joint
- capable of sustaining weight bearing forces
Anterior Talofibular ligament
- reisist PF, Inversion, ADD
- anterior translation of talus on mortise
(lateral ankle sprain)
Calcaneofibular ligament
-resist inversion, DF
-resist subtalar inversion
(2nd most common inversion ankle sprain)
Posterior talofibular ligament
- resist DF, ABD, Inversion
- posterior translation of talus on mortise
deltoid ligament
-resist eversion
Special medial ligaments and what they resist
tibiotalar, tibionavicular, tibiocalcaneal
-tibiotalar: EV, DF
-tibionavicular:
TCJ - EV & PF
TNJ - EV & AB
-tibiocalcaneal
STJ EV
Talocrural Joint Arthrokinematics PlantarFlexion
“Fixed Shank”
convex = talus concave = tib/fib complex
convex on concave - roll & slide in opposite direction
Talocrural Arthrokinematics Dorsiflexion “Fixed Shank”
roll: counter-clockwise from lateral view
slide: posterior slide of taluss
DF & ankle mortise
talus fill mortise and spread malleoli apart
- creates tight grip on talus
- strong ligament & tendon support
PF & ankle mortise
talus leaves mortise and malleoli come together
-loose grip w/o ligamentous support = unstable
non-weight bearing DF/PF
dorsiflexion accomponied by external rotation (25/2.5)
plantar flexion includes IR (35/1)
weight bearing DF/PF
DF - includes eversion/ IT
PF - includes Inversion & ER of tibia
ATF Test
anterior drawer
-put pt in PF / anterior displacement of talus
Talar Tilt
positive finding = pain
-talus tilts or gaps excessively compared to uninjured side
stabilize tib/fib while other hand on heel - rounding foot into inversion
Major articulations within the foot
subtalar joint transverse tarsal joint tarsometatarsal MTP IP
subtalar joint is stabilized by
-interosseous ligament: EV
-deltoid: EV
-cervical: INV
CFL: INV
Open Chain of subtalar
- Supination: calcaneal inversion, PF, ADD
- Pronation: calcaneal eversion, DF, ABD
Closed Chain of subtalar
Supination: calcaneal inversion, talar DF & ABD
- MLA elevation
- role up the chain
Pronation: calcaneal eversion, talar PF, and ADD
- MLA depression
- role up the chain
function of subtalar joint
main interconnection between mobility of foot mechanism & stability of ankle/leg
-allows for adaptive positioning
Midfoot is stabilized by
medial longitudinal arch, specialized ligaments, joint capsule and muscle
heavily reliant on STJ
Talonavicular
- convex head of talus
- concave navicular bone
ball and socket like
inferior support by spring ligament
greater degree of joint play/mobility
calcaneocuboid
articulation of anterior calcaneus and proximal cuboid
- support by long and short plantar ligaments
- little movement
plantar calcaneonavicular ligament
shock absorbing = spring ligament
- main supporter of medial longitudinal arch of support
- excessive prolonged pressure leads to permanent stretch
- lowered longitudinal arch (fallen arch)
Medial Foot & Ankle Ligaments
- plantar aponeurosis
- long plantar ligament
- short plantar ligament
Mutli-axis functional mobility
parallel = mobile adapter divergent = rigid lever
longitudinal and oblique axis contribute to pronation & supination
middle functional segment
transverse tarsal arch held together by interosseous ligament ; flattens on weight bearing
foot elasticity: accommodate uneven surfaces
what muscle eccentrically impacts arch?
tibialis posterior
Foot locomotion supination
subtalar inversion, forefoot ADDuction and PF
foot locomotion pronation
subtalar eversion, forefoot ABD, DF
foot locomotion: running
heel strike: rearfoot inversion
foot rolls forward: forefoot contact; supination (Inversion, PF, ADD)
Mid-stance: eversion, abduction and beginning of d-flex
(pronation - prolongs foot contact with ground)
tarsometatarsal joint
permit gliding and sliding
medial tarsometatarsal
most ROM
no ligamentous restriction
intermed. tarsometatarsal
2nd cuneiform shorter in length
2nd MT is longest & wedged
strongest joint; little ROM
lateral tarsometatarsal
intermediate ROM
MTP joint (forefoot)
largest ROM of any joints (flexion/extension)
- important in propulsion
- knuckle like joint
IP joint
- greater mobility
- hinge (big toe can hyperextend)
- reinforced with plantar and collateral ligaments
1st MTP
integral to static and dynamic mobility task
- force generation; efficiency
(heel lift / propulsion)
Windlass Mechanism
tension from plantar fasciae when digits are extended
- extension of MTP creates tension in plantar fascia
- role of overpronation
intrinsic muscles
plantar surface of foot
strong in central portion
supports arch
extrinsic support muscles
helps maintain arch, stabilize joints, shock absorption (quiets landing)
control toes
where do major muscles pass malleoli?
PF: gastroc & soleus
DF: tibialis anterior, EHL, & EDL
Inver/Sup: TA, TP, FHL, FDL
Ever/Pron: peroneus brevis and peroneus longus
MOVERS malleoli
act as pulley - alter angle of pull for muscles
force plate gait sensors
initial peak = heel hits
second peak = pushing off
posterior tibialis dysfunction
- role in maintaining supination & MLA
- elevated arch in supination
- going into PF,carried ADD & inversion
if person is pronated, there will be a change in the ability to maintain arch
orthotics
support surrounding arch structures and limit pronation moment at foot/ankle complex
pes planus
low arch
flexible lever = push off
progressive loading of supporting ligaments of MLA
Pes Cavus
high arch shortens foot length pressure of metatarsal head toes claw bear more weight on heel
Heel height effect on MT heads
3/4 inch heel - 22% increase
2 inch heel - 57% increase
3 1/4 inch - 76% increase
Hallux Valgus
- distal end outward (proximal inward)
- 2nd most frequent forefoot surgery
- 94% of cases are women
bunion
medial side of foot at 1st MP joint
sesamoid shift and thicken MT head
March fracture
“Stress fracture”
hairline fracture across 2nd MT
occurs because 2nd metatarsal joint has little movement and not accustomed to stress level or repetition. (runners)
