Foot and Ankle Flashcards
What are the 7 tarsus of the foot?
- calcaneus
- talus
- navicular
- cuboid
- cuneiforms (3)
Why are there 5 metatarsus (3 phalanges per metatarsal), but only 14 phalanges?
Only 2 phalanges articulate with the first metatarsal, while the other 4 metatarsus articulate with 3 phalanges
Describe the fascia of the foot in terms of dorsal and plantar aspects:
- dorsal: thin and continuous with extensor retinaculum
- plantar: plantar fascia, central part thickens to form plantar aponeurosis (becomes tendinous)
- a part of the plantar fascia and arises from calcaneous posteriorly
- consists of longitudinally arranged band of dense connective tissue
- covers entire length of sole
- divides into five bands (enclose digital tendons)
- helps support the longitudinal foot arches
plantar aponeurosis
- plantar aponeurosis inflammation at proximal attachment (calcaneus)
- pain is most severe after sitting and getting out of bed
- causes: running, high impact exercise, worn out shoes, overweight
- may lead to: bony process (“heel spur” or “calcaneal spur”) may develop especially from medial calcaneal tubercle
plantar fasciitis
What are the 2 muscles present in the dorsum of foot?
- innervation?
- extensor hallucis brevis (1st phalanx)
- extensor digitorum brevis (2nd-4th phalanges): joins respective long tendons approximately at the MP joint
(these muscles form a fleshy mass on lateral part of dorsum of foot, anterior to lateral malleolus)
- innervation: deep fibular N.
What is the arrangement of the plantar foot muscles and what is their role?
- arranged in 4 layers
- these muscles are synergists: help maintain foot arches and stand on uneven ground
What are the plantar muscles of the first layer? (3)
(3 short muscles that extend from calcaneous to phalanges)
- abductor digiti minimi
- flexor digitorum brevis
- abductor hallucis
What are the plantar muscles of the second layer? (2)
(keeps toes in line and prevents them turning laterally when flexor digitorum longus is contracting)
- quadratus plantae: joins tendon of FDL to calcaneous, assits FDL in flexing lateral four digits
- lumbricals: originate from FDL tendons, medial aspect of extensor expansion, flex mp joint, extend pip and dip joints
*FHL and FDL tendons are located in this layer, but not considered a part of 2nd layer plantar muscles*
What are the plantar muscles present in the third layer? (3-4)
(3 short muscles to first and fifth digits (anterior half of foot))
- flexor digiti minimi brevis
- adductor hallucis: transverse head and oblique head
- flexor hallucis brevis: two heads (medial and lateral) cover plantar surface of first metatarsal, tendons have sesamoid bones, protect first metatarsal head and tendon of FHL when standing/walking
What are the plantar muscles of the fourth layer?
(interossei between metatarsals)
- 3 plantar interossei: “pad” digits 3, 4, and 5 toward 2nd digit
- 4 dorsal interossei: “dab” digits 2, 3, and 4 away from midline of 2nd digit
*fibularis longus and tibialis posterior tendons are also in this layer*
- a foot deformity characterized by lateral deviation of great toe
- surrounding tissues swell and resultant pressure/friction against shoe causes bursa to form
- if the bursa becomes tender/inflammed, this is a bursa
- inflammed areas of thick skin, corns, may form over proximal interphalangeal joints
- possible causes: wearing pointy heeled shoes
hallux valgus
What is one of the main causes of toe deformities?
What are the 4 main types of toe deformities?
- in part, because of shortened flexor muscles which can override lumbrical function
- mallet toe (flexion in distal IP joint), hammer toe, claw toe, trigger toe (extended mp, flex ip)
- toe deformity (usually of 2nd toe)
- proximal phalanx is permanently hyperextended at metatarso-phalangeal joint
- middle phalanx is plantarflexed at the proximal interphalangeal joint
- distal phalanx is extended
hammer toe
- toe deformity characterized by hyperextension of metatarso-phalangeal joints
- flexion of the distal and proximal interphalangeal joints
claw toes