The leg and foot week 5 Flashcards
What is the popliteal fossa? What forms the roof of the popliteal fossa and what structures pierce the roof? What are the boundaries of the popliteal fossa? What passes through the popliteal fossa?
The popliteal fossa is an area of transition btwn the posterior thigh and leg and serves as a route by which structures pass from one region to the other. Is a diamond shaped space formed btwn muscles of the posterior thigh and leg.
The roof of the popliteal fossa is formed by a specialization of the fascia lata called the popliteal fascia. Superificial fascia and skin cover the roof. The posterior cutaneous femoral nerve and the small saphenous vein pierce the popliteal fascia.
Superior borders:
medial: semimembranosus and semitendinosus
lateral: biceps femoris
inferior borders:
medial: medial head of the gastrocnemius
lateral: lateral head of the gastrocnemius and the plantaris
Anterior wall (floor):
popliteal surface of the femur (superiorly), capsule of the knee joint (centrally) and hte popliteus muscle with its fascia (inferiorly)
Contents: popliteal artery and vein, termination of the small saphenous vein into the popliteal vein (in the roof), tibial nerve, common fibular nerve, posterior femoral cutaneous nerve, popliteal lymph nodes and vessels
What is plantar faciitis and what are some causes?
inflammation of the plantar aponeurosis or plantar fascia that serves in part to support the arches of the foot. variety of causes including tight calf musculature, high arches, flat feet, or repetitive stress (like running)
What is comparment syndrome? What is it caused by?
painful and potentially dangerous condition where pressure builds within the crural compartments of the leg and compromises the neurovascular structures that lie deep to muscles and fascia in this region. may be acute (ocurring after sig injury like a fx) or chronic (in athletes due to muscular hypertrophy and/or swelling with repetitive activities)
Most structures pass btwn the thigh and leg through the ____ ___ and pass btwn the leg and foot btwn the ___ ____. The leg is divided into three compartments by _____ ____ (extensions of the crura) and the ____ _____.
popliteal
tarsal tunnel
intermuscular septa
interosseus membrane
What are the 2 muscle groups of the posterior leg and what comprise those groups? What is the innervation and blood supply of muscles in this comparment? What is the general fxn of muscles in this comparment?
superficial group: gastrocnemius, plantaris, soleus
deep group: popliteus, flexor hallucis longus
flexor digitorum longus
tibialis posterior
all of the muscles of the posterior comparment of the leg are innervated by the tibial nerve and receive blood supply from the posterior tibial artery
In general, muscles of the posterior comparment of the leg plantarflex and invert the foot and flex the toes.
What is clinically significant about the placement of the neurovasculature in the posterior compartment of the leg?
the posterior tibial artery and the tibial nerve lie in the deep layer of the posterior leg. Swelling of muscles in the deep compartment as occurs in compartment syndrome can compress this neurovasculature and affect the foot.
What is the origin, insertion, fxn, and innervation of the gastrocnemius?
origin: medial and lateral epicondyles of the femur
insertion: calcaneus via the Achilles’ tendon (tendocalcaneus)
fxn: plantar-flexes the foot at the talocrural joint (most efficiently when the leg is extended at the knee, flexes teh leg at the knee joint
innervation: tibial nerve
What is the origin, insertion, fxn, and innervation of the soleus?
origin: posterior aspects of the proximal fibular head and neck and tibia (soleal line)
insertion: calcaneus via the Achilles’ tenddon
fxn: Plantarflexes the foot (“workhorse” of plantarflexion)
innervation: tibial nerve
What is the origin, insertion, fxn, and innervation of the plantaris?
origin: lateral epicondyle of the femur (proximal to the gastrocneumius)
insertion: calcaneus
fxn: weakly assisits in plantarflexion of the foot
innervation: tibial nerve
What is the origin, insertion, fxn, and innervation of the popliteus?
origin: lateral suface of the lateral femoral condyle
insertion: posterior tibia above the soleal line
fxn: laterally rotates the femur on the tibia (unlocks the knee). this allows the knee to go from extension (where the femur is medially rotated on the tibia) to flexion.
innervation: tibial nerve
What is the origin, insertion, fxn, and innervation of the flexor digitorum longus?
origin: medial, posterior tibia below the soleal line
insertion: plantar surface of the distal phalanges of digits 2-5 (bases)
fxn: flexes the digits, plantarflexes the foot at the talocrural joint, inverts the foot at the subtalar joint
innervation: tibial nerve
What is the origin, insertion, fxn, and innervation of the tibialis posterior?
origin: posterior tibia (inferior to soleal line), posterior fibula, interosseus membrane
insertion: navicular tuberosity (the major insertion), all 3 cuneiforms, cuboud, and bases of metatarsals 2, 3, and 4
fxn: plantarflexes the foot at the talocrural joint and inverts the foot at the subtalar joint
innervation: tibial nerve
What is the origin, insertion, fxn, and innervation of the flexor hallucis longus?
origin: posterior surface of the inferior fibula, inerosseus membrane
insertion: plantar surface of the distal phalanx of the great toe (base)
fxn: flexes the great toe, weakly assists in plantarflexoin of the foot and inversion of the foot at the subtalar joint
innervation: tibial nerve
Identify these muscles of the posterior leg. What group of muscles do they comprise?
superficial group
Identify these muscles of the posterior leg. What group of muscles do they comprise?
deep group
Dicuss how arteries course through the posterior leg and what muscles they supply.
The popliteal artery is the major blood supply of the leg and foot and enters the posterior compartment of the leg through the popliteal fossa. It enters the posterior leg btwn the gastrocnemius and popliteus and then passes deep to the soleus to enter the deep region of the posterior leg. It then divides into an anterior tibial artery and a posterior tibial artery. The anterior tibial artery passes through an aperture in the interosseus membrane to enter and supply the anterior comparmemnt of the leg. The posterior tibial artery and its branches supply the posterior and lateral compartments of the leg. The fibular artery, a major branch of the posterior tibial artery, courses on the lateral aspect of the posterior comparment supplying adjacent muscles. It gives off perforating branches through the intermuscular septum to supply the lateral compartment of the leg but it does not course through the lateral compartment of the leg.
The common fibular nerve divides into what branches? Where is is more common to have a lesion of this nerve (before or after branching) and what sx may result?
Divides into superficial and deep branches. Is more common to have a nerve lesion of the common fibular nerve before it branches where it is less protected (is in superficial position as it wraps around head of the fibula). Could have resulting weakness in muscles that the superficial and/or deep branches innervate.
Motor deficits: inability to dorsiflex the foot against gravity (resulting in a foot drop), significant weakness in ankle eversion, weakness with extension of the toes, steppage gait (excessive hip flexion to compensate for lack of dorsiflexion)
sensory deficits: decreased sensation on the lateral leg, decreased sensation on the dorsum of the foot
What nerves do the medial and lateral sural nerves branch from? What do they innervate?
The medial sural nerve is a branch of the tibal nerve that originates high in the leg btwn the two heads of the gastrocnemius. It travels around the lateral malleolus and into the foot and innervates the skin of the inferior posterior lateral leg, the lateral side of the foot, and the little toe.
The lateral sural nerve is a branch of the common fibular nerve. It innervates the skin over the superior lateral leg.
Identify these muscles of the anterior compartment of the leg.
Discuss the courses of the neurovasculature of the anterior comparment of the leg as they course into the foot. What do they innervate/supply?
As stated, the anterior tibial artery passes from the posterior comparment of the leg to the anterior compartment of the leg through the interosseus membrane to supply the anterior compartment of the leg. It turns into the dorsalis pedis artery in the foot.
The deep fibular nerve is a branch of the common fibular nerve. It enters the anterior compartment of the leg and gives off muscular branches to muscles in the region. Also gives cutaneous innervation to skin btwn the first and second toe. Can think of it as the flip-flop nerve.
Identify the muscles of the lateral compartment of the leg.
Discuss the innervation of the superficial fibular nerve.
It innervates the muscles in the lateral compartment of the leg (fibularis longus and brevis) and supplies most of the cutaneous innervation to the dorsum of the foot
What structures pass through the tarsal tunnel? What can happen in tarsal tunnel syndrome?
structures that pass through the tarsal tunnel pass under the flexor retinaculum and do so from anterior to posterior as follows:
tibialis posterior
flexor digitorum longus
posterior tibial artery and vein
tibial nerve
flexor hallucis longus
In tarsal tunnel syndrome, can get venous stasis of the posterior tibial vein that causes compression of the tibial nerve.
Describe the cutaneous innervation of the dorsum of the foot.
After the tibial nerve and posterior tibial artery pass through the tarsal tunnel, what do they branch into in the foot? Why is this clinically relevant?
They branch into the medial and lateral plantar nerve and artery to supply/innervate the intrinsic muscles of the foot. In tarsal tunnel, can get compression of the tibial nerve and get sx in the intrinsic muscles of the foot.
Describe the cutaneous innervation to the plantar surface of the foot.
Describe the cutaneous innervation of the anterior leg and dorsum of the foot.
Describe the cutaneous innervation of the posterior leg and heel of foot.
