14 - Ankle Joint and Foot Flashcards
What muscles do plantarflexion?
gastrocnemius soleus TP FDL FHL PL PB Plantaris
What muscle medially rotates leg?
Popliteus
What muscles do inversion?
Tibialis Anterior and Posterior (NO compartment)
What muscles do eversion?
Peroneus Brevis and Longus
What muscles do dorsiflexion?
TA
EDL
EHL
Peroneus Tertius
What bones make up the ankle joint and what actions?
- articulation of the TALUS and the tibia and fibula
- allows dorsiflexion and plantarflexion
What bones make up the subtalar joint and what actions are permitted here?
- the inferior talus and superior calcaneus
- allows inversion and eversion
Talocalcaneonavicular Joint Complex?
- involves the talus, calcaneus and navicular
What is the lateral boundary of the foot?
CUBOID (not lateral cuneiform)
What are the 3 cuneiforms?
Medial, intermediate, lateral
Bones of the foot?
- distal, medial, proximal phalanges. Big toe only has proximal and distal
- metatarsals
- cuneiforms
- cuboid
- navicular
- talus
- sustentaculum tali (medial to calcaneus, inferior to talus)
- calcaneus
What is the purpose of the tarsal bones?
To support the ankle joint
Describe the shape of the talus?
> superior is dome shaped (talar dome) that articulates with tibia and fibula
wider at the ANTERIOR than posterior
Why is the talus wider at the anterior than the posterior?
> means the ankle joint is more stable in certain positions
during dorsiflexion the anterior talus is engaged which is wider and so it sits TIGHT in the joint and is relatively stable
during plantarflexion, the talus is rolled forwards so the thinner posterior portion of the talus is articulating with the fibula and tibia - this is LESS tight and less stable
plantarflexion; high heels, toes, stepping off curb is less stable
What is the mortis?
Cup shaped area the tibia and fibula make for the talus to sit in
What are important ligaments at the ankle joint?
- Tibiofibular Ligament
- Lateral Ligament Complex
- Medial Ligament Complex
What is the tibiofibular ligament?
> thickened distal portion of the interosseous membrane
holds the tibia and fibula tight so the articulating talus sits well in the mortis
it is a syndesmosis joint (permits very little movement)
The distal tibiofibular joint forms a … joint
Syndesmosis Joint
Bony projection of the medial calcaneus is called the …
Sustentaculum tali - sits under and supports the talus
The neck of the talus projects forward to articulate with the …
Navicular
What bones help make the arch of the foot?
The navicular and cuneiforms (higher than cuboid and calcaneus)
How many phalanges do the toes have?
Great toe has 2, lateral 4 toes have 3
What does the subtalar joint involve?
Calcaneus, talus and navicular (inversion and eversion)
Where is the hinge for inversion/eversion?
- Hinge is through an oblique plane through the subtalar joint
- lifting up lateral/medial border of foot
Myotome and muscles involved in dorsiflexion?
L4/L5 TA EDL EHL PT
Myotome and muscles involved in plantarflexion?
S1/S2 Gastroc Soleus Plantaris TP EDL EHL PL PB (run posterior to lateral malleolus)
Myotome and muscles involved in inversion?
L4
TP
TA
Myotome and muscles involved in eversion?
L5/S1
PL
PB
PT
What ligaments are usually rupturing/stretching when you sprain your ankle?
Medial or lateral ligament complexes
> usually the lateral complex as medial is broad and strong
Describe the lateral ligament complex
- has 3 parts to it
- finer than medial side
- 1x fibula to calcaneus
- 2x taliofibular ligaments (1 anterior and 1 posterior)
Describe the Medial Ligament Complex
- is a much stronger complex than lateral
- has 4 parts but don’t find as discrete; is a broad strong complex
- called the deltoid ligament
- 1x TIBIA to calcaneus
- 1x Tibia to navicular
- 2x Tibia to talus
Which of the ankle ligaments is the strongest?
The deltoid ligament/medial ligament complex
What is the most common way to injure ankle?
Inversion and plantarflexion - position of relative weakness and instability
How should the ankle joint look in an AP x ray?
> The space between the talus and tibia should be thin (tightly associated) and evenly spaced
if the foot shifts laterally the space will increase
medial/deltoid ligaments damaged
What is a syndesmotic injury?
- joint between distal fibula and tibia
- on lateral side between fibula and talus the gap is wider
- tibiofibular ligament has ruptured; usually overlaps slightly/tightly associated
- can overlook as no fracture
Describe the neurovascular structures in the foot
- coming posteriorly round the medial malleolus in the tarsal tunnel, the tibial n and posterior tibial artery split
- posterior tibial artery becomes the medial and lateral plantar arteries
- tibial nerve becomes the medial and lateral plantar nerves (supplies sole of foot)
Where will you find the pulse of the posterior tibial artery?
Half way between the medial malleolus and the heel
What maintains the arches of the foot?
- Shape of the bones
- Ligaments
- Tendons
> many bones/ligaments to give flexibility to absorb shock and act as spring board
What is the highest arch of the foot?
The medial arch
Plantar Aponeurosis?
- deep fascia of foot and first thing beneath skin
- tough and covers plantar surface of foot
- plantarfascitis; inflammation of this
How many muscle layers are there in the sole of the foot?
4
In which muscle layer does the NM bundle run in in the sole of the foot?
> tibial n and posterior tibial artery
> 2nd layer of foot
