Mechanics of the Foot and Ankle Flashcards
What is the tibiotalar joint stabilized by?
- Joint stabilized by capsule,
- deltoid ligament,
- anterior talofibular (ATFL-always tear first!),
- calcaneofibular (CFL)
- posterior talofibular (PTFL) ligaments
What are the subunits of the deltoid ligament? What injury usually occurs here?
- Comprised of: tibionavicular, anterior and posterior tibiotalar, and tibiocalcaneal ligaments
- Usually bone injury (fracture) occurs before this ligament is damaged.
Describe the lateral ligaments of the tibiotalar joint
- The ATFL (always tear first in inversion sprain)
- Attaches to the lateral malleolus & to the neck & lateral articular facet of the talus
- The Calcaneofibular
- Attaches to the lateral malleolus & to the tubercle of the lateral surface of the calcaneus
- The PTFL
- Attaches to the lateral malleolus & to the lateral tubercle of the post process of the talus
What are the major motions of the ankle?
- Plantar flexion (to 50 degrees)
- Performed by gastrocnemius & soleus (major players)
- Performed by plantaris (if you have one!), tibialis post, flexor hallucis longus & flexor digitorum longus (minor players)
- Dorsiflexion (to 20 degrees)
- Performed by tibialis anterior (major player)
- Performed by extensor digitorum longus & extensor hallucis longus (minor players)
When is the ankle most stable?
In dorsiflexion
Accessory ankle motions?
•Side-to-side glide, rotation, abduction and adduction only if the joint is plantar flexed.
Major motions of the subtalar joint?
- Major motions are calcaneal ABDuction (valgus) & ADDuction (varus) in relationship to a fixed talus
- So the heel deviates in and out
The talus articulates with the…
The calcaneus articulates with the…
Navicular
cuboid
Motion of the hind foot is the combined motions of the…
• Talocalcaneal (subtalar), Talonavicular, and Calcaneocuboid
Motions of the hind foot?
Inversion and eversion
Where is the midfoot?
•Between Transverse Tarsal joint and Tarsometatarsal joint
Motions of the midfoot?
Pronation and supination
Describe pronation
Pronation= Eversion + Dorsiflexion + ABduction (calcaneus & foot)
Describe supination
Supination= Inversion + Plantar flexion + ADduction (calcaneus & foot)
Motion of the tarsometatarsal joints?
•flexion & extension
Motions of the intermetatarsal joints?
sliding
MTP movements?
Flexion, extension, abduction, and adduction.
Also slide, rotate and can provide long axis traction
Movements of IP’s
Flex and extend
What are the longitudinal arches?
Lateral and medial
Describe the lateral arch. What is it built for?
- Weight bearing & elastic
- Firm osseous structure
- Made up of calcaneus, cuboid, 4th& 5th Mets
- Limited mobility
- Built to transmit weight & thrust to the ground
Describe the medial arch. What is it’s primary purpose?
- More mobile & higher than the lateral arch
- Made of (calcaneus), talus, navicular, the cuneiforms and 1-3Mets
- Controlled by plantar ligament, plantar fascia, tibialis post, FDL, FHL & intrinsic muscles of the foot
- Does not have firm osseous support
- Changes to adapt to terrain
The medial arch helps to control…
gait
What is a high medial arch caused by?
•Caused by ADduction of foot and a varus calcaneus
What causes a dropped medial arch?
- Caused by ABduction of foot and a valgus calcaneus & dorsiflexion of the ankle
- Extreme pronation!!!
What does the foot musculature do with regard to the arch?
What do they not do?
They help control it for balance and gait.
Do not support the arch.