Lecture 26: Ankle joint and foot Flashcards
the foot is divided into what bones?
tarsal bones
metatarsal bones
phalanges
tarsal bones:
-calcaneus
-talus
-navicular
-cuboid
-three cuneiforms( medial, intermediate, lateral)
3 regions of the foot
- Hind foot - Talus and calcaneus
- Mid foot - Cuboid, navicular, 3 cuneiforms
- Forefoot- Metatarsals, phalanges
why do oblique x-rays of foot?
-get better view of the joint spaces
what are these?
sesamoid bones
ankle joint parts
The ankle joint - distal ends tibia & fibula articulates with the talus
Allows dorsiflexion and plantarflexion
- Tibia and fibula form a mortice for
the talus to sit in - Mortice part made up of 2 parts -
tibia and fibula - When walking load on this joint
can be X5 body weight (more
when running/jumping)
when is the ankle joint most stable?
-ankle joint is most stable in dorsiflexion
- Articular surface of talus is wider
anteriorly - So in dorsiflexion the joint between
the talus and tibia becomes “tighter”
as less space to move side to side - So the ankle joint is most stable in in
dorsiflexion - More likely to roll ankle in high heels
when is the ankle joint least stable?
Plantarflexion
* More likely to roll ankle in high
heels
subtalar joint
- The subtalar joint involves the inferior
aspect of the talus and the superior aspect
of the calcaneus - Allows for inversion and eversion
CLINICALLY
The talocalcaneonavicular joint complex
involves talus, sustentaculum tali (of the
calcaneus), and navicular. The movements
at this joint are pronation and supination
/inversion and eversion.
Calcaneus has several small articulations, which allows for movement while maintaining stability
Pronation/supination vs inversion/eversion of foot
Supination = inversion + adduction + plantar flexing
Pronation = eversion + abduction + dorsiflexion
why does calcaneus have many articulation sites?
Calcaneus has multiple articular surfaces.
Allow for a articulation with adjacent bones providing flexibility - but not too much relative movement
do not need to know these details
ligaments of ankle joint
- The ankle joint itself is stabilized by medial
and lateral ligament complexes
+posterior talofibuar lig at the back( do not need to remember, just know its there)
lateral ligament complex: parts
The lateral ligament complex is
composed of three parts: anterior and
posterior talofibular ligaments and a
calcaneofibular ligament
- Prevent Inversion or varus of ankle