16: Foot And Ankle Flashcards
Plantar aponeurosis
Central longitudinal thickening of plantar fascia that divides into five bands that enclose digit tendons
Plantar fasciitis
Plantar aponeurosis inflammation at calcaneus
What can plantar fasciitis cause?
Heel spurs, esp. on medial calcaneal tubercle
Extensor digitorum brevis insertion
Phalanges 2-4 MP joints
The two dorsal foot muscles form a fleshy mass where?
Lateral dorsum, anterior to lateral malleolus
Dorsal foot innervation vs plantar foot innervation
Dorsum: deep fibular N
Plantar: medial and lateral plantar nerves
Plantar layer 1 muscles
Abductor digiti minimi, flexor digitorum brevis, abductor hallucis
Plantar layer 2 muscles
Quadratus plantae, lumbricals
Tendons in layer 2 and layer 4
Layer 2: FHL, FDL
Layer 4: tibialis posterior, fibularis longus
Quadratus plantae function
Joins FDL tendons to calcaneus, assisting FDL in flexing the lateral four digits
What forms the medial aspect of the extensor expansion?
Lumbricals
Lumbrical origin
FDL tendon
Lumbrical action
Flexes MP joint, extend PIP and DIP joints
Which muscle’s tendons have sesamoid bones in them?
Flexor hallucis brevis
Purpose of sesamoid bones in food
Protect 1st metatarsal head and tendon of FHL when staining and walking
Which is the ghost muscle in layer three that “doesn’t really exist”
Opponens digiti minimi
Plantar interossei action
Adduct digits 2,3,4, away from midline of 2nd
Dorsal interossei action
Abduct digits 2,3,4 away from midline of 2nd digit
Hallux valgus
Lateral deviation of great toe -> swelling and pressure that can cause a bursa called a bunion
Corns
Inflamed area of thick skin over proximal interphalangeal joints
What causes mallet toe, hammer toe, claw toe, and trigger toe deformities?
Shortened flexor muscles
Which toes are involved in mallet, hammer, claw, and trigger toe?
Mallet/hammer/claw: lateral four toes
Trigger: large toe
Mallet toe
Flexion of DIP
Hammer toe
Extension at MP joint + flexion at PIP
Claw toe
Extension at MP joint + flexion at PIP and DIP
Trigger toe
Extended MP, flexion at IPs
What nerve forms the medial and lateral plantar N’s
Tibial N
Medial plantar N path
Deep to abductor hallucis -> anterior between abductor hallucis + flexor digitorum brevis
Medial plantar N termination
Into four sensory branches near metatarsal bases
Four muscles innervated by medial plantar N (rest of plantar foot innervated by lateral plantar N)
- Abductor hallucis
- Flexor digitorum brevis
- Medial-most lumbrical
- Flexor hallucis brevis
Lateral plantar N path
Deep to abductor hallucis -> anterolaterally deep to flexor digitorum brevis
Termination of lateral plantar N
Superficial + deep branches
Five nerves that innervate the cutaneous foot and the area they innervate
- Deep fibular N: small area between 1st and 2nd digits
- Superficial fibular N: rest of dorsum
- Sural N branches: lateral foot
- Medial plantar N: medial plantar
- Lateral plantar N: lateral plantar
Which two arteries in the dorsal and plantar foot meet to form the plantar arch?
Deep plantar A + lateral plantar A
Where does the posterior tibial A divide into medial and lateral plantar A’s?
Deep to abductor hallucis
What does the lateral plantar A run with?
Lateral plantar N
Medial ankle ligament
Deltoid ligament
Four parts of the deltoid ligament
- Anterior tibiotalar
- Tibionavicular
- Tibocalcaneal
- Posterior tibiotalar
Medial ankle ligament A
Stabilizes ankle during eversion
Three lateral ligaments of the ankle
- Posterior tibiofibular
- Anterior tibiofibular
- Anterior talofibular
Two ligaments that make up the tibiofibular syndesmosis
Anterior tibiofibular + posterior tibiofibular L
Which ligaments are involved in high ankle sprains
Lateral ligaments
The ankle joint: other name + bones involved
Talocrural joint; tibia, fibula, talus
When is the malleoli grip on trochlea of talus the strongest?
During dorsiflexion
Talocrural joint type
Hinge synovial joint
Only movement allowed in talocrural joint
Dorsiflexion/plantarflexion
Transverse tarsal joint: two joint components
Calcaneocuboid + talonavicular joints
What motion does the transverse tarsal joint add to?
Inversion/eversion
Where is a standard transection for a surgical foot amputation
Transverse tarsal joint
Subtalar joint other name
Talocalcaneal joint
Main movement of subtalar joint
Inversion/eversion
What ligament supports the subtalar joint?
Interosseous talocalcaneal L
What action causes almost all ankle sprainns?
Inversion
Functions of the foot arches
Absorb shock during weight bearing, make foot adaptable to surface and weight changes
Three major ligaments that stabilize the arches of the foot
- Spring (plantar calcaneonavicular L)
- Long plantar L
- Shot plantar L
Four muscles that stabilize the medial portion of the longitudinal arch
- FHL
- FDL
- Tibialis posterior
- Tibialis anterior
Two major stabilizers of the transverse arch
- Adductor hallucis
2. Transverse ligaments
Difference between stabilizers of the forefoot vs of the metatarsus and tarsus
Forefoot: passive stabilizers only
Metatarsus and tarsus: active stabilizers only
Pes transversoplanus
Loss of transverse arch
Pes planus
Loss of longitudinal arch (usually medial portion) -> flat feet
What two things become abnormally stretched in pes planus
Plantar L’s + plantar aponeurosis