Ankle And Foot Complex Flashcards
FOOT COMPLEX
divided into 3 functional segements
hindfoot - posterior segment composed of talus and calcaneus
midfoot - middle segment composed of cuboid, navicular, and 3 cuneiforms.
forefoot- anterior segment composed of metatarsals and phalanges
ANKLE AND FOOT COMPLEX
25 bones and 25 component joints Proximal and distal tibiofibular joints Ankle joint or talocrural joint talocalcaneal or sutalar joint transverse tarsal joints ( talocuboidal and talonavicular) 5 tarsometarsal joints metatarsophalangel joint 9 interphalangeal joint
ANKLE/ FOOT MOTION
Dorsiflexion/ plantarflexion occurs in sagittal plane around coronal axis
inversion/ eversion occurs in frontal plane around longitudinal or AP axis
abduction/ adduction occurs in transverse plane around vertical axis
FOOT MOTION
pronation and supination occurs in each cardinal axis coupled with DF/PF, INV/EVE, ABD/ADD.
NWB: PRONATION coupled with DF, EVE, ABD, and SUPINATION is coupled with PF, INV, ADD
VALGUS/VARUS FOOT
valgus/calcaneovalgus - toe out/ increase in the medial angle b/w calcaneus and posterior leg
varus/calaneovarus- toe it/ decrease in the medial angle b/w calcaneus and posterior leg.
ANKLE JOINT
ankle is aka as talocrural joint. articulation b/w distal tibia and fibula proximally and body of talus distally. SYNOVIAL HINGE JOINT. joint capsule and associated ligaments have single oblique axis with 1 dof DF/PF
ANKLE JOINT STRUCTURE :
PROXIMAL ARTICULAR SURFACES
concave distal tibia and of tibial/ medial and fibular / lateral malleoli: refers to MORTISE that is adjustable
function of ankle joint is dependent on stability of tibiofibular mortise
mobility role of mortise depends on fibula
PROXIMAL TIBIOFIBULAR JOINT
plane synovial
articulation of head of fibula ( concave facet) with posterlateral tibia( convex facet).
joint capsule with anterior and posterior tibiofibular ligaments and interosseus membrane
motion at this joint is small.
DISTAL TIBIOFIBULAR JOINT:
syndesmosis or fibrous
union of CONCAVE TIBIAL facet and CONVEX FIBULAR facet.
no joint capsule
anterior and posterior tibiofibular ligaments and interosseus membrane .
extremely strong articulations
ANKLE JOINT:
DISTAL ARTICULAR SURFACE :
body of talus is the distal articualtion of ankle joint
body of talus has 3 articular facets:
* large lateral fibular
* small medial tibial
* trochelar superior
body of talus WIDE ANTERIORLY THAN POSTERIORLY
ANKLE JOINT CAPSULE
FAIRLY THIN AND WEAK ANTERIORLY AND POSTERIORLY
LIGAMENTS OF ANKLE JOINT:
anterior and posterior tibiofibular : important for mortise stability
tibiofibular interosseous membrane : supports proximal and distal tibiofibular joints
medial and lateral collateral ligaments: maintain contact and congruence of the mortise and talus, also control medial-lateral joint stability. some portions also support subtalar joint
MEDIAL COLLATERAL LIGAMENT
AKA DELTOID LIGAMENT.
XTREMELY STRONG
eversion or and pronation can injure this ligament
LATERAL COLLATERAL LIGAMENT
3distinct bands:
anterior talofibular: weakest and often injured and stressed with PF, MR, and INV
posterior talofibular: rarely torn in isolation
calcaneofibular ligament: stressed with DF and INV
control INVERSION AND OR SUPINATION of ankle or talus
components are weaker and more susceptible to injury than medial collateral ligament
AXIS OF ANKLE JOINT
in neutral position, axis passes through lateral malleolus and body of talus
angled at 14 degrees
PF- foot moves medially, DF- foot moves laterally
tibial torsion- toe out position in normal standing and 20-40 degrees of ER of tibia
ANKLE JOINT FUNCTION:
normal ROM: DF 20 degrees, PF 50 degrees.
walking 10 degrees DF
loose packed position is PF
with DF wider talus gets wedged in the ankle mortise
DF/PF limited by soft tissue approximation
WB:DF: tibia rotates over talus
ankle joint less stable in PF when narrow posterior is within mortise.
STRUCTURES LIMITING DF/PF:
ACTIVE OR PASSIVE TENSION IN gastrocnemius ( knee extension )and soleus (knee flexed) : primary limitation of DF
TENSION IN Tibialis anterior, EHL, and EDL : primary limitation of PF and protect medial aspect of ankle.
Fibularis longus and brevis protect lateral aspect of ankle.
THE SUBTALAR JOINT:
aka talocalcaneal joint
composite joint
3 separate articulations b/w inferior calcaneal and superior talus
provide triplanar movement
in WB subtalar joint is critical in dampening proximal rotational forces while maintaining contact of the foot with the ground.
SUBTALAR JOINT STRUCTURE:
posterior articulation is the largest and formed by concave talus and convex calcaneus body.
anterior smaller and medial talocalcaneal articulation formed by two convex facets on the inferior body and neck of talus and concave facets on calcaneus.
sulcus is the bony tunnel between these 3 articulations.
bony outcropping on the calcaneus is sustentaculum tali
posterior articulation has its own capsule but medial and anterior articulations share a capsule with talonavicular joint.
SUBTALAR JOINT LIGAMENTS:
calcaneofibular, lateral talocalcaneal, cervical and interosseous ligaments
cervical is the strongest
inferior extensor retinaculum provides stability to subtalar joint.
SUBTALAR JOINT FUNCTION:
motion of talus on the calcaneus is complex twisting or screwlike motion.
triplanar motion of talus around single oblique joint axis producing Pronation/ Supination.
SUBTALAR AXIS
the motion about oblique axis cross all 3 planes.
Pro/sup modeled by single oblique hinge joint
motions are coupled and occur simultaneously as talus twists around subtalar joint
includes equal magnitude of EV/INV and ABD/ADD but less DF/PF.
NWB SUBTALAR JOINT MOTION
Supination is coupled with calcaneal motions of EVERSION , ABDUCTION, PLANTAR FLEXION.
Pronation is coupled with calcaneal motion of INVERSION, ADDUCTION, DORSIFLEXION .
WB SUBTALAR JOINT :
Supination is coupled with CALCANEAL INVERSION, TALAR MOTION OF ABD, DF, AND TIBIOFIBULAR LATERAL ROTATION.
Pronation is coupled with CALCANEAL EVERSION, TALAR MOTION OF ADD, PF AND TIBIOFIBULAR MEDIAL ROTATION.
calcaneus is locked or on the ground but can move INV/EV, but limited DF/PF, ADD/ABD.