2.5 Flashcards
Motion of forefoot
Flexion, extension, abduction, adduction
Midline is 2nd digit
Motion of the ankle
flexion and extension = dorsiflexion and plantarflexion
Motion of foot and ankle
inversion and eversion at subtalar joint
Supination and pronation at multiple joints
- complex movement of gait cycle
- Supination: inversion, adduction, plantarflexion
- Pronation: eversion, abduction, dorsiflexion
Pathologic motion of foot and ankle
Ankle joint is the most frequently injured major joint of the body.
Most common type is inversion sprain of deltoid ligament.
Eversion sprain: sprain of lateral ligament (ATFL)
Osteology of distal tibia and fibula
Syndesmosis joint between them
Distinct from proximal tib-fib joint which is a synovial joint
3 ligaments:
- anterior tibiofibular ligament (green)
- posterior tibiofibular ligament (pink)
- interosseous membrane (purple)
High ankle sprain
Injury to distal tib-fib ligament, often the anterior ligament
Mechanism is usually a forced external rotation to a dorsiflexed ankle
Foot bones
1st digit has no middle phalanx, but 2 sesamoid bones
The sustentaculum tail is a part of the calcaneus that supports the talus.
Parts of the foot
Forefoot
- metatarsals
- phalanges
Midfoot
- cuboid
- navicular
- cuneiforms
Hindfoot
- calcaneus
- talus
Lisfranc injury
Fracture of dislocation of midfoot
Most common dislocation
Arches of the foot
Distribute body weight and absorb shock
Adjustments for walking on uneven surfaces
Springboard for walking and running
Have dynamic and static support
- Dynamic: muscles support with contractions that respond to demands of the foot
- with contributions from intrinsic and extrinsic muscles
- Static: bones and ligament
- structures give constant support
- spring ligament (plantar calcaneonavicular ligament)
- helps maintain medial arch
- supports head of talus and talonavicular joint
- sustentaculum tail to navicular
Pes planus
Flat feet
Long arches can distupt foot function
Joints of the foot
Talocrural (ankle) joint
- hinge with tibia
Talonavicular
- ball and socket
Subtalar
- planar with calcaneus
Talocrural joint
- trochlea of talus
- tibia
- lateral and medial malleolus
- structure:
- anterior trochlea is wide
- stabilizes joint during dorsiflexion
weakest in plantarflexion
Ankle ligaments
Deltoid: MCL of the ankle
- strong and prevents eversion
- 4 parts:
- tibionavicular
- tibiocalcaneal
- posterior and anterior tibiotalar
Lateral collateral ligament
3 parts
Weaker than deltoid… inversion injuries are more common
Anterior talofibular ligament (ATFL): second most injured
Ankle tendons
Tom Dick And Harry
Tibialis posterior
Digitorum longus (flexor)
Artery: posterior tibial artery and nerve
Hallicus longus (flexor)
Tarsal tunnel syndrome: an entrapment syndrome of the tibial nerve within the tarsal tunnel
Common fractures
Pott fracture/dislocation
- fibula fracture
- ATFL torn
- medial malleolus fracture
- deltoid ligament torn
Musculature of dorsum of foot
Extensor muscles:
- extensor hallicus brevis
- extensor digitorum brevis
Second plantar foot layer
Lumbricals (4)
- Flex MTP
- Extend PIP & DIP
Quadratus plantae (2 heads)
1st lumbrical is unipennate and originates from one tendon.
Lumbricals 2-4 are bipennate and originate from adjacent tendon.
The tendons of flexor hallicus longus and flexor digitorum longus are also located in this layer.
Master knot of henry
Tendons of FHL and FDL interconnect where they cross.
Quadratus plantae often inserts at this location and inserts onto FHL and FDL.
Plantar aponeurosis
Known as plantar fascia
Thickening of deep fascia of sole of foot
Connects calcaneal tuberosity with each toe
Functions:
- supports both longitudinal arches
- protection of underlying neurovasculature
Plantar fasciitis
- Straining and inflammation of aponeurosis
- common in runners
- pain most at medial calcaneus
Dorsum arteries
Sole neurovasculature
Dorsalis pedis pulse
Have patient extend big toe to find tendon of extensor hallicus longus, palpate just lateral to tendon
Furthest palpable vessel from the heart, making it important for assessing peripheral circulation
Posterior tibial pulse
Have patient invert foot to relax flexor retinaculum, palpate just posterior to medial malleolus
Veins
Deep veins follow arteries of same name
Superficial veins drain into dorsal venous arch
- Small saphenous vein drains - lateral side
- Great saphenous vein - medial side
Nerves
Tibial nerve bifurcates deep to abductor hallicus.
Medial and lateral plantar nerves parallel to the arteries of the same name.
Together they supply all intrinsic muscles of sole and skin of sole.
Innervation of the foot
Medial leg to heel: saphenous nerve (branch of femoral nerve)
Dorsum: common fibular nerve
- motor: deep fibular nerve
- cutaneous: superficial fibular nerve
Plantar foot: tibial nerve
- motor and sensory
