Lower leg and Ankle Flashcards
what type of joint is the proximal tibiofibular joint?
planar synovial joint
what type of joint is the distal tibiofibular joint?
syndesmosis - not a synovial joint
what prevents ankle adduction
medial malleolus and lateral (fibular) collateral ligaments
what makes up the lateral (fibular) collateral ligaments
anterior and posterior talofibular ligament and calcaneofibular ligament
What prevents ankle abduction
lateral malleolus and medial (tibial) collateral ligaments
what makes up the medial collateral ligaments
anterior and posterior tabiotalar and tabionavicular ligaments
when is the ankle most stable and why?
most stable during dorsiflexion b/c talus is trapezoid shape and during dorsiflexion the top 2 corners are locked between 2 malleolus
what motions occur at the ankle?
dorsi and plantarflexion
what motions occur at the intertarsal joints?
inversion and eversion
muscles that pass over the ankle anteriorly do what motion?
dorsiflex
dorsiflexion is achieved by what muscles?
extensor muscles innervated by posterior division nerve (fibular nerve)
what motion is achieved at the intertarsal joint from muscles that go around the medial edge?
inversion
what motion is achieved at the intertarsal joint from muscles that go around the lateral edge?
eversion - only done by fibularis muscles
tibialis anterior
Proximal attachment – tibia, fibular, and interosseous membrane
Distal attachment – base of 1st metatarsal
Innervation - fibular nerve L4, L5 ventral rami
Action - inversion at intertarsal joint, dorsiflexion
extensor digitorum longus
Proximal attachment – tibia, fibula, interosseous membrane
Distal attachment – extensor expansion 2-5
Innervation – fibular nerve L4, L5 ventral rami
Action – dorsiflex ankle, extend digits 2-5
extensor hallucis longus
Proximal attachment – tibia, fibula, interosseous membrane
Distal attachment – extensor expansion
Innervation – fibular nerve L4, L5 ventral rami
Action – dorsiflex ankle, invert, extend digit 1 (done when you swing so you don’t drag your big toe while walking)
fibularis tertius
Proximal attachment – fibula
Distal attachment – base of 5th metatarsal
Innervation – fibular nerve L4, L5 ventral rami
Action – dorsiflex at ankle, evert at intertarsal joint
what prevents bowstringing at angle
superior/inferior extensor/fibular retinaculum
fibularis longus
Proximal attachment – fibula
Distal attachment – base of metatarsal 1 and 1st (medial cuneiform)
Innervation – superficial fibular nerve L5, S1, S2
Action - plantarflexion (cross posterior to lateral malleolus), evert at intertarsal joint and also maintains transverse arch at intertarsal joint
fibularis brevis
Proximal attachment – fibula
Distal attachment – base of metatarsal 5 (same as tertius)
Innervation – superficial fibular nerve L5, S1, S2
Action - plantarflexion (cross posterior to lateral malleolus), evert at intertarsal joint
what is the gastroc so powerful?
anaerobic muscle - powerful but has a short life span
what muscle is used for walking and long distance running and why?
soleus b/c it is aerobic
gastrocnemius
Proximal attachment – medial and lateral condyle of femur
Distal attachment – heal through achilles tendon
Innervation – tibial nerve S1, S2
Action – flex knee (synergize w/ hamstrings), plantarflex at ankle
soleus
Proximal attachment – tibia, fibula, interosseous membrane
Distal attachment – calcaneus (Achilles) tendon
Innervation – tibial nerve S1, S2
Action – plantarflex at ankle
popliteus
Proximal attachment – lateral condyle
Distal attachment – tibia, runs through joint capsule
Innervation – tibial nerve L4, L5, S1
Action – flex at knee, main function is to external rotate femur and internally rotate tibia – counter rotate tibia and femur to unlock knee during walking phase – counter rotation to unlock the knee
what is main function of popliteus
rotate femur laterally at knee to “unlock” from full extension
tibialis posterior
Proximal attachment – tibia, fibula, interosseous membrane
Distal attachment – calcaneus, cuboid, cuneiform, and bases of middle metatarsals 2-4
Innervation – tibial nerve L4, L5
Action – plantarflex at ankle, invert at intertarsal joints, maintains transverse arch at intertarsal joints like fibularis longus
flexor hallicis longus
Proximal attachment – fibula and interosseous membrane, and tibia – more lateral posterior leg
Distal attachment – digit 1 distal phalange
Innervation – S2, S3
Action – plantarflex at ankle, flex digit 1 (toe off when you walk), invert at intertarsal
flexor digitorum longus
Proximal attachment – medial posterior side of leg – tibia, fibula, interosseous membrane
Distal attachment – distal phalange of digits 2-5
Innervation – S2, S3
Action – plantarflex at ankle and flex digits 2-5, invert at intertarsal
boundaries of popliteal fossa
- superior lateral = biceps femoris
- superior medial = semitendinosus and semimebranosus
- inferior lateral and medial = gastrocnemius
contents of popliteal fossa
popliteal artery and vein, small saphenous vein, tibial and fibular nerve (sciatic), popliteus muscle