Lower Leg & Foot Flashcards
Bones of the foot
Tarsals
Metatarsals
Phalanges
Tarsal bones
Proximal: Talus, Calcaneus
Intermediate: navicular
Distal: Cuboid, medial cuneiform, intermediate cuneiform, lateral cuneiform
Talus bone
Superior: ankle joint (tib/fib)
Inferior: subtalar (calcaneus)
anterior: talonavicular (navicular)
Calcaneus
“heel bone”
Superior: subtalar (talus)
Anterior: calcaneocuboid (cuboid)
Navicular
Posterior: talus
Anterior: all 3 cuneiforms
Lateral: cuboid
Tuberosity on plantar surface (tibialis posterior)
Cuboid
Posterior: calcaneus
Anterior: 4th & 5th MTT
Inferior surface has groove for fibulas longus
Lateral Cuneiform
Anterior: 3rd MTT
Attachment for flexor hallux brevis
Middle Cuneiform
Anterior: 2nd MTT
Medial Cuneiform
Anterior: 1st MTT
Attachment for: tibialis anterior, tibialis posterior, fibularis longus
Metatarsals
Convex dorsally. Consists of head, neck, shaft and base.
Proximal: tarsometatarsal joints
Lateral: intermetatarsal joints
Distal: metatarsophalangeal joints
Arches of the foot
2 longitudinal arches (medial and lateral)
Anterior transverse arch
Medial longitudinal arch
Formed by: calcaneus, talus, navicular, first 3 metatarsal bones
Supported by:
Muscle: tibialis anterior, tibialis posterior, fibulas longus, flexor digitorum longus, flexor hallucis, intrinsic foot muscles
Ligaments: plantar ligaments, deltoid ligament (medial ligament of ankle)
Lateral longitudinal arch
Formed by: calcaneus, cuboid, 4th and 5th MTT
Supported by:
Muscular: fibularis longus, flexor digitorum longus, intrinsic foot muscles
Ligaments: plantar ligaments
Transverse arch
Formed by: metatarsal bases, cuboid, three cuneiforms
Supported by:
Muscular: fibularis longus, tibialis posterior
Ligaments: plantar ligaments, deep transverse metatarsal ligaments
Borders of the Tarsal Tunnel
Floor: medial aspect of tibia, talus, calcaneus
Roof: flexor retinaculum (between medial malleolus and medial tubercle of calcaneus)
Contents of the Tarsal Tunnel
Tibialis posterior tendon Flexor digitorum longus tendon Posterior tibial vein Posterior tibial artery Tibial nerve Flexor hallucis longus tendon
Ankle joint
AKA talocrural joint
Formed by tibia, fibular, talus
Hinge joint.
Movements are dorsiflexion and plantar flexion
Ligaments of the ankle joint
Tibiofibular ligaments Medial ligament (deltoid ligament) Anterior talofibular ligament Posterior talofibular ligament Calcaneofibular ligament
Deltoid ligament
Medial malleolus to talus/calcaneus/navicular
Function to resist over eversion of ankle
Anterior talofibular ligament
ATFL
Lateral malleolus to lateral aspect of talus
Posterior talofibular ligament
PTFL
From lateral malleolus to posterior aspect of talus
Calcaneofibular
CFL
Lateral malleolus and calcaneus
Pott’s fracture
Bimalleolar/trimalleolar fractures of ankle
- Forced eversion pulls on medial ligaments producing avulsion fracture of medial malleolus
- Talus moves laterally breaking off lateral malleolus
- Tibia is forced anterior shearing off distal/posterior part against talus
Dorsal Muscles of the foot
Extensor digitorum brevis
Extensor hallucis brevis
Plantar muscles of the foot
First layer:
Abductor hallucis
Flexor digitorum brevis
Abductor digiti minimi
Second layer:
Quadratus plantae
Lumbricals
3rd layer:
Flexor hallucis brevis
Adductor hallucis
Flexor digiti minimi brevis
4th layer:
Plantar interossei
Dorsal interossei
Extensor digitorum brevis
Origin: calcaneus, interosseous talocalcaneal ligament and inf. extensor retinaculum
Insertion: proximal phalanx of great toe and log extensor tendons of toes 2-4
Innervation: deep fibular nerve
Function: aids extensor digitorum longus at MTPJs and IPJs
Extensor hallucis brevis
Origin: calcaneus, interosseous talocalcaneal ligament and inf. extensor retinaculum
Insertion: base of proximal phalanx of great toe
Innervation: deep fibular n.
Function: aids extensor hallucis longus in extending great toe at MTPJ
Abductor hallucis
Origin: medial tubercle of calcaneus, flexor retinaculum and plantar aponeurosis
Insertion: medial base of proximal phalanx of great toe
Innervation: medial plantar nerve
Function: abducts and flex great toe
Flexor digitorum brevis
Origin: medial tubercle of calcaneus and plantar aponeurosis
Insertion: middle phalanges of lat. 4 digits
Innervation: medial plantar n.
Function: flexes lat. 4 digits at PIPJs
Abductor digiti minimi
Origin: medial and lateral tubercles of calcaneus and plantar aponeurosis
Insertion: lateral base of proximal phalanx of 5th
Innervation: lateral plantar n.
Function: abductd and flexes 5th digit
Quadratus plantae
Origin: medial and lateral plantar surface of calcaneus
Insertion: tendons of flexor digitorum longus
Innervation: lateral plantar n.
Function: assists FDL in flexing lateral 4 digits
Lumbricals
Origin: tendons of flexor digitorum longus
Insertion: extensor hoods of lateral 4 digits
Innervation: most medial: medial plantar n. lateral 3: lateral plantar n.
Function: flexes a MTPJs and extends IPJs
Flexor hallucis brevis
Origin: plantar surface of cuboid and lateral cuneiforms, tendon of post. tibialis
Insertion: base of proximal phalanx of great toe
Innervation: medial plantar n.
Function: flexes proximal phalanx at MTPJ
Adductor Hallucis
Origin: oblique head: bases of 2nd/3rd/4th MTT. Transerve head: plantar ligaments of MTPJs.
Insertion: lateral base of proximal phalanx of great toe
Innervation: deep branch of lateral plantar n.
Function: adduct great toe
Flexor digiti minimi brevis
Origin: base of 5th MTT
Insertion: proximal phalanx of 5th digit
Innervation: superficial branch of lateral plantar n.
Function: flexes proximal phalanx of 5th digit
Plantar interossei
Origin: medial side of 3rd/4th/5th MTT
Insertion: medal side of phalanges 3-5
Innervation: lateral plantar nerve
Function: adduct digits 3-5, flex MTPJs
Dorsal interossei
Origin: side of 1-5 MTT
Insertion: 1st: medial side of proximal phalanx of second digit. 2-4th: lateral side of proximal phalanx 2-4
Innervation: lateral plantar n.
Function: abducts digits 2-4 and flex MTPJs
Compartments of the lower leg
Anterior
Lateral
Deep posterior
Superficial posterior
Muscles of the anterior compartment of leg
Tibialis Anterior
Extensor digitorum longus
Extensor Hallucis Longus
Fibularis (peroneal) Tertius
Muscles in the lateral compartment of the leg
Fibularis (peroneal) longus
Fibularis (peroneal) brevis
Muscles in the superficial posterior compartment of the leg
Gastrocnemius
Plantaris
Soleus
Muscles in the deep posterior compartment of the leg
Popliteus
Tibialis posterior
Flexor Digitorum longus
Flexor hallucis longus
Tibialis Anterior
Origin: lateral surface of tibia
Insertion: medial cuneiform and base of 1st MTT
Innervation: deep fibular nerve
Function: dorsiflexion and inversion of foot
Extensor Digitorum Longus
Origin: lateral condyle of tibia and medial surface of fibular
Insertion: splits into 4 insertions onto each toe
Innervation: deep fibular n.
Function: extension of lateral 4 toes, dorsiflexion of foot
Extensor Hallucis Longus
Origin: medial surface of fibular shaft
Insertion: base of distal phalanx of great toe
Innervation: deep fibular n.
Function: extension of great toe, dorsiflexion of foot
Fibularis (peroneal) tertius
Origin: extensor digitorum longus and medial surface of fibula
Insertion: 5th MTT
Innervation: deep fibular n.
Function: eversion and dorsiflexion of foot
Fibularis (peroneal) longus
Origin: superior and lateral surface of fibula. descends posterior to lateral malleolus and travels under the foot.
Insertion: plantar aspect of medial cuneiform and base of 1st MTT
Innervation: superficial fibular (peroneal) nerve
Function: eversion and plantar flexion of foot
Fibularis (peroneal) brevis
Origin: inferolateral surface of fibular shaft
Insertion: tubercle on 5th MTT
Innervation: superficial fibular (peroneal) nerve
Function: eversion of foot
Gastrocnemius
Origin: lateral head: lateral femoral condyle. Medial head: medial femoral condyle.
Insertion: calcaneal tendon
Innervation: tibial n.
Function: plantar flexes at the ankle joint, moderate flexion of knee
Plantaris
Absent in 10% Origin: lateral supracondylar line of femur Insertion: calcaneal tendon Innervation: tibial n. Function: plantar flexes ankle joint
Soleus
Origin: soleal line of tibia and proximal fibula
Insertion: calcaneal tendon
Innervation: tibial n.
Function: plantar flexes foot at ankle
Popliteus
Origin: lateral condyle of femur and post form of lateral meniscus
Insertion: above origin of soleus
Innervation: tibial n.
Function: laterally rotates femur, ‘unlocking’ knee to allow flexion
Tibialis posterior
Origin: interosseous membrane and posterior surface of tibia and fibula
Insertion: plantar surface of medial tarsal bones
Innervation: tibial n.
Function: inverts and plantar flexes foot
Flexor digitorum longus
Origin: medial surface of tibia
Insertion: plantar surface of lateral 4 digits
Innervation: tibial n.
Function: flexes lateral 4 toes
Flexor Hallucis longus
Origin: posterior surface of fibula
Insertion: plantar surface of great toe
Innervation: tibial n.
Function: flexes great toe
Tibial nerve, roots and origins
L4-S3
Branch of the sciatic nerve
Arising at the apex of popliteal fossa
Tibial nerve innervations
Motor:
Superficial posterior: plantaris, soleus, gastrocnemius
Deep posterior: popliteal, flexor hallucis longus, flexor digitorum longus, tibialis posterior
Intrinsic muscles: all except extensor digitorum brevis
Sensory: Combines with common fibular to create Sural nerve Sole of foot with 3 branches: Medial calcaneal branches (S1/2) Medial plantar nerve (L4/5) Lateral plantar nerve (S1/2)
Common fibular nerve, roots and origins
L4 - S2
Branch of sciatic
Arising from apex of popliteal fossa
Common fibular nerve innervations
Motor:
Short head of biceps femoris
Superficial fibular n.: lateral compartment
Deep fibular n.: anterior compartment
Sensory: Sural (with branches from tibial): Lateral sural cutaneous nerve superficial fibular nerve Deep fibular nerve
