Foot Flashcards
dorsum foot muscles
-extensor digitorum brevis
-extensor hallucis brevis
-innervation- deep fibular nerve
-blood supply- dorsalis pedis artery
-assist the extensor longus muscle with extending the toes (MP and IP joints)
blood supply to anterior leg compartment
-anterior tibial artery (one of terminal branches of popliteal artery)
-after branching from popliteal artery -> passes through gap in superior part of interosseous membrane to enter the anterior compartment of leg
-courses inferior on anterior surface of interosseous membrane between tibialis anterior and extensor digitorum longus muscles
-when anterior tibial artery courses ankle joint -> becomes dorsalis pedis artery that supplies dorsal foot
-arcuate branch forms arch across foot that gives rise to dorsal metatarsal arteries -> ultimately dorsal digital arteries
dorsalis pedis artery
-evaluated when performing PE of peripheral vascular system
-farthest palpable vessel from heart
-palpated between tendons of extensor hallucis longus and extensor digitorum longus
motor/sensory innervation: superficial fibular nerve
-motor innervation in lateral compartment
-courses between fibularis longus and brevis to provide them with innervation along its path
-sensory innervation- at distal third of leg -> pierces deep fascia to enter the superficial fascia where it becomes cutaneous nerve
-cutaneous nerve continues its course inferiorly to supply distal third of lateral leg and dorsum of foot
motor/sensory innervation deep fibular nerve
-motor- innervates muscles in anterior compartment of leg as well as extensor brevis muscle in dorsal foot
-sensory- innervates small cutaneous region located at webspace between 1st and 2nd toes
cutaneous innervation: dorsal foot
-superficial fibular nerve- most of dorsal foot
-deep fibular nerve- supplies webspace between 1st and 2nd toes
-medial- saphenous nerve
-lateral- sural nerve
foot drop
-results from complete paralysis of foot dorsiflexor muscles
-paralysis results in toe pointing (dropping) towards the floor when raising foor off the ground during walking
-to life their foot higher off the ground to prevent dragging of toes -> pt compensates by increasing knee flexion
-alteration in gait -> steppage gait
foot slap
-results from weakness (paresis) of foot dorsiflexor muscles (partial foot drop)
-when heel strikes ground during walking, weakness of dorsiflexor muscles results in inability to slowly lower the foot to the ground -> results in an audible slapping of the foot against the ground
most common cause of foot drop/slap
-due to compression of neuron fibers within the common fibular (peroneal) nerve or deep fibular (peroneal) nerve as it courses within the anterior compartment
neurological causes of foot drop include the following conditions
-charcot marie tooth disease
-diabetic neuropathy
-multiple sclerosis
tarsal bones
-calcaneus- calcaneus tuberosity and sustenaculum tali (talar shelf)
-talus- head and neck
-navicular
-cuboid
-cuneiforms- medial, intermediate, lateral
-metatarsals 1-5
-phalanges- proximal, middle, and distal
foot regions
7 tarsals, 5 metatarsals, 14 phalanges
-3 anatomical and functional groups:
-hindfoot- talus and calcaneous
-midfoot- navicular, cuboid, and cuneiforms
-forefoot- metatarsals and phalanges
calcaneal (achilles) tendons
-attaches to calcaneal tuberosity
-narrow space between anterior surface of the calcaneal tenon and superior part of posterior surface of calcaneal tuberosity is occupied by retrocalcaneal bursa
-irritation/inflammation of retrocalcaneal bursa, or of subcutaneous calcaneal bursa (achilles bursa) can cause pain at heel and ankle
microscopic tears of collagen fibers of calcaneal tendon
-result in tendinitis
-can ultimately lead to calcaneal tendon rupture
-steroids (systemically or injected) around tendon -> increase probability of calcaneal tendon rupture
distal tibiofibular joint
-distal tibia and fibula are held tightly together by interosseous membrane and the anterior and posterior tibiofibular ligaments
-syndesmotic sprain (high ankle sprain)- injury to distal tibiofibular syndesmosis with possible disruption of distal tibiofibular ligaments and interosseous membrane
subtalar and transverse tarsal joints
-subtalar joint- articulation between inferior surface of the talus and the superior surface of calcaneus
-transverse tarsal joint- consist of 2 joints:
-talonavicular- articulation between talus and navicular bone
-calcaneocuboid joint- articulation between calcaneus and the cuboid
deltoid ligament
-fibrous capsule of ankle is fairly weak -> must rely on ligaments to provide support
-deltoid ligament (medial collateral) - fan shaped ligament whose apex is located on medial malleolus of tibia and attaches to navicular, talus, calcaneus
-strong ligament and functions to prevent excessive range of motion (primarily eversion)
-has 4 parts:
-tibionavicular ligament
-tibiocalcaneal ligament
-anterior tibiotalar ligament
-posterior tibiotalar ligament
plantar fascia and plantar foot muscles
-plantar fascia- deep fascia of sole of the foot
-plantar aponeurosis- thickened central portion of fascia which spans distance between calcaneus and toes
plantar fasciitis
-joggers heel, tenis heel, policemans heel
-most common cause of heel pain
-caused by repetitive microtrauma to plantar fascia
plantar foot muscle: layer 1
-abductor hallucis- medial plantar artery
-flexor digitorum brevis- medial and lateral plantar artery
-abductor digiti minimi- lateral plantar artery
-abductor hallucis and flexor digitorum brevis innervated by medial planar nerve
-abductor digiti minimi innervated by lateral plantar nerve
-abductor hallucis- abducts and flexes 1st digit (big toe)
-flexor digitorum brevis- flexes lateral 4 digits
-abductor digiti minimi- abduct and flexes 5th digit (little toe)
plantar foot muscles: layer 2
-intrinsic plantar foot muscles
-quadratus plantae- lateral plantar nerve
-lumbricals- medial 1- medial plantar nerve; lateral 3- lateral plantar nerve
-both supplied by medial and lateral plantar artery
-quadratus plantae- assists in flexor digitorum longus with flexing lateral 4 digits
-lumbricals- flex proximal phalanges, extend middle and distal phalanges of lateral 4 digits
plantar foot muscles layer 3
-flexor hallucis brevis
-adductor hallucis- transverse and oblique heads
-flexor digiti minimi brevis
-medial and lateral plantar nerves and arteries
medial and lateral sesamoids of foot
-located within the 2 tendons of flexor hallucis brevis muscle
-sesamoids function to increase mechanical advantage of flexor hallucis brevis, assist in weight bearing and determine the line of action of the flexor hallucis longus muscle
-disruption of sesamoids leads to disruption of normal functioning of metatarsophalangeal joint
plantar foot muscles layer 4
-intrinsic foot muscles consist of 2 groups of muscles that abduct and adduct the toes
-both innervated by lateral plantar nerve:
-dorsal interossei
-plantar interossei
hallux valgus
-bunion
-deformity
-may be caused by pressure from improperly fitted footwear or degenerative joint disease
-characterized by lateral deviation of the great toe
-L in vaLgus -> lateral
foot arches
-2 types of foot arches: longitudinal and transverse
-longitudinal arch- medial and lateral longitudinal arch
-transverse arch- half arch lying inferior to forefoot and between lateral and medial longitudinal arches
longitudinal arch
-medial longitudinal arch- largest and most clinically significant -> located from proximal to distal along the medial aspect of foot
-lateral longitudinal arch- lies from proximal to distal along the lateral aspect of foot and is more shallow that medial arch
weight bearing areas of foot
-located at anterior and posterior aspect of longitudinal arches
-these are calcaneal tuberosity -> heads of 2nd-5th metatarsals and the sesamoid bones of the 1st metatarsals
dynamic and passive support of arches
-arches are formed by tarsal and metatarsal bones- supported by foots ligaments and tendons
-dynamic support of longitudinal arch is provided by intrinsic foot muscles in sole of foot as well as tibialis posterior, tibialis anterior, and flexor hallucis longus muscles
-passive support provided by plantar aponeurosis, short plantar ligament, long plantar ligament, and plantar calcaneonavicular (spring) ligament
-spring ligament- important bc it supports head of talus at peak of medial longitudinal arch of foot
acquired flat feet
-fallen arches
-inferomedial displacement of head of talus
-most likely to be secondary to dysfunction of tibialis posterior muscle
blood supply to plantar foot
-posterior tibial artery enters foot inferior to medial malleolus through the tarsal tunnel
-after passing through tunnel it bifurcates into 2 vessels
-medial plantar artery- courses through foot along the medial edge of abductor hallucis
-lateral plantar artery- courses between quadratus plantae and flexor digitorum brevis muscles
-distally in foot -> vessel curves medially to form deep plantar arch
-arch supplies blood to metatarsals and phalanges via plantar metatarsal arteries and plantar digital arteries
-termination point of arch is where it joins with deep plantar artery -> terminal branch of dorsalis pedis artery
innervation of plantar foot
-tibial nerve- enters foot inferior to medial malleolus through tarsal tunnel
-branches:
-medial calcaneal nerve- branches from tibial nerve within tunnel -> provides sensory innervation to posterior and plantar heel
-terminal branches:
-medial plantar nerve- motor to intrinsic foot muscles and sensory to medial region of plantar aspect of foot
-lateral plantar nerve- motor to intrinsic foot muscles and sensory to lateral region of plantar aspect of foot
lateral and medial plantar nerves
-often compromised in diabetic pts
-loss of sensation to feet along with poor blood flow -> render these pts susceptible to development of foot ulcers
-foot ulcers are undetected and untreated
-can lead to infection and possibly the need to amputation
-most amputation a re preventable with regular care and proper footwear
achilles tear
-left calf and ankle pain
-going out to lunge
-snap -> calcaneal tendon (watershed area)
-irregular mass in posterior calf
-diffculty doing plantar flexion
-easier time with dorsiflexion bc no opposing pull
-Tomson’s test- squeeze gastrocnemius muscles look for flexion -> if no flexion -> tendon tear
plantar fascitis
-running for long times
-persistent
-anterior to calcaneal tuberosity
which ligaments maintain the longitudinal arch of foot
-posterior tibial ligament
-intrinsic plantar ligaments
-people with drop foot/slap have large arch
