Interval 8: Leg and foot Flashcards
What is the largest joint in the human body?
-Knee joint
What 3 bones articulate in the formation of the knee joint?
-femur, tibia, and patella
The articulation between the patella and femur is the _________ articulation. What is the larger one called?
- patellofemoral articulation
- tibiofemoral is larger
T/F: the fibula does not take place in the articulation of the knee joint.
True
The support of the weight of the body on the vertically-posed ends of the 2 long bones is intrinsically an unstable arrangement, but the knee is secured by what 4 compensating mechanisms?
- 2-fold to 3-fold expansions of the weight bearing surfaces of the femur and tibia
- application to the joint of strong collateral intra-articular ligaments
- reinforcing tendons and aponeurosis
- strong capsule
The knee is strengthened by ligaments of the articular capsule and by ligaments inside the articular capsule. The ligaments of the articular capsule are?
- patella ligament
- oblique popliteal ligament
- arcuate ligament
- fibular and tibial collateral ligaments
Patellar ligament
- extension of the quadriceps tendon
- strengthens anterior and lateral parts of capsule
Oblique popliteal ligament is part of what tendon? and it works with the arcuate ligament to strengthen which dimension of the capsule?
- semimembranosus tendon
- posterior support
The fibular collateral ligament strengthens the _____ side of the capsule, while the tibial collateral ligament strengthens the _______ side.
- fibular: lateral
- tibial: medial
Where does the fibular collateral ligament extend from and to?
-from lateral epicondyle of femur to attach to the head of the fibula
Where does the tibial collateral ligament extend from and to?
-from medial epicondyle of femur to attach to the medial aspect of tibia
The deep fibers of the tibial collateral ligament are attached to the _________.
-medial meniscus
When are the fibular and tibial collateral ligaments the most taut?
-when knee is fully extended
Fibular and tibial collateral ligaments limit _________ of the knee when the knee is flexed
-abduction and adduction
What are the 2 important intra-articular ligaments?
- anterior and posterior cruciate ligaments
- ACL and PCL
- medial and lateral menisci
ACL arises from the rough, non-articular area anterior to the intercondylar eminence of the tibia. It extends in what direction(s) to the posterior part of the medial surface of the ________.
- posteriorly, superiorly, and laterally
- lateral femoral condyle
PCL is ____, ______, and _______ than the ACL
-stronger, shorter, and less oblique
The PCL arises from an area posterior to the tibial eminence and passes in what directions to the lateral surface of the medial femoral condyle.
-anteriorly, superiorly, and medially
What do the ACL and PCL do?
- prevent movements of the tibia forward and backward under the femoral condyles
- ACL prevents anterior displacement, and PCL prevents posterior displacement
The ACL is most taut when? what is it resisting in this stance?
- knee is extended
- resists hyperextension by preventing anterior displacement of the tibia on the femur
When is the PCL most taut and what it is resisting in this stance?
- knee is flexed
- resists excessive flexion by preventing posterior displacement of tibia on femur
Role of medial and lateral menisci
-intracapsular, crescent-shaped fibrocartilages that attach to tibia and act as shock absorbers
Medial vs. lateral miniscus
- medial: shape of the letter C, less mobile, and is attached to deep fibers of the tibial collateral ligament
- lateral: shape of the letter o, more mobile, separated from the fibular collateral ligament by the tendon of the popliteus
What trio of injuries is called the terrible triad?
-rupture of tibial collateral ligament, tear of the ACL, injury to medial meniscus
Like the elbow, the knee is also a ______ joint, and can thus be extended and flexed. Additionally, the knee can be _________.
- hinge joint
- hyperextended, and some lateral and medial rotation occurs during flexion and extension
What are the compartments of the leg?
-anterior, posterior, and lateral compartments
What muscle types are mainly contained within the compartments?
- anterior: muscles that produce extension (dorsiflexion) and inversion of foot
- posterior: flexion (plantar flexion) and inversion
- lateral: flexion (plantar flexion) and eversion
Another name for the ankle joint is…..
-talocrural joint
What articulations does the talocrural joint consist of?
- tibial and talus (tibiotalar joint)
- fibula and talus (talofibular joint)
What plane does the talocrural joint allow movement in?
-sagittal
Plantar flexion
-movement in which the angle between leg and foot increase
Dorsiflexion
-movement in which angle between foot and leg decreases
The subtalar joint is formed by articulations between the _____ and ________ and allows for motion primarily in the ______ plane.
- talus and calcaneus
- coronal plane
Inversion
-movement in which plantar surface of the foot faces medially
Eversion
-movement in which the plantar surface of the foot faces laterally
Name the blood supply and innervation of the anterior compartment of the leg
- deep fibular nerve
- anterior tibial artery
4 muscles of the anterior compartment of the leg
- tibialis anterior
- extensor digitorum longus
- extensory hallucis longus
- fibularis tertius
Tibialis anterior
- dorsiflexes the foot at the ankle joint
- inverts foot
Extensor digitorum longus
- extends lateral digits 2 to 4
- dorsiflexes foot at ankle joint
Extensor hallucis longus
- extends great toe
- dorsiflexes the foot
Fibularis tertius
-dorsiflexes and everts foot
Name the layers, blood supply, and innervation of the posterior compartment of the leg
- superficial and deep layers of muscle
- innervated by tibial nerve
- posterior tibial, fibular, and popliteal arteries
List the 3 muscles of the superficial layer of the posterior leg compartment
- Gastrocnemius
- Plantaris
- Soleus
Gastrocnemius
- plantarflexes foot
- flexes knee
Plantaris
- plantarflexes the foot
- flexes the knee
Soleus
-plantarklexes the foot
Calcaneal tendon
- common tendon of gastrocnemius and soleus
- connects gastrocnemius and soleus muscles to calcaneous bones
Rupture of calcaneal tendon
- caused by forceful pushoff during an activity such as sprinting when running or jumping in basketball game
- bruising is often apparent and visible bulge forms in posterior region of leg due to muscle shortening
If one tears the calcaneal tendon, why does a bulge appear int he posterior region of the leg?
-muscle shortening
Most common treatment of calcaneal tendon rupture
-surgery
4 muscles of the deep layer of the posterior compartment of the leg
- popliteus
- flexor hallucis longus
- flexor digitorum longus
- tibialis posterior
Popliteus
-unlocks knee joint by laterally rotating the femur on a fixed tibia
Flexor hallucis longus
-flexes great toe
Flexor digitorum longus
-flexes digits 2-5
Tibialis posterior
-inverts and plantar flexes the foot, providing support to medial arch of foot during walking
Blood supply and innervation of lateral compartment of leg
- superficial fibular nerve
- anterior tibial and fibular arteries
2 lateral compartment muscles
- fibularis longus
- fibularis brevis
Fibularis longus
-plantarflexes and everts the foot
Fibularis brevis
-plantarflexes and everts the foot
The tibial nerve enters the gluteal region with the ___________ nerve in the sciatic nerve by passing through the greater sciatic foramen _____ to the piriformis muscle
- common fibular nerve
- inferior
The tibial nerve courses through the posterior thigh deep to the hamstrings before separating from the common fibular nerve where?
-superior border of the popliteal fossa
Tibial nerve courses in the posterior part of the leg with the ___________ and then passes through the tarsal tunnel and into the sole of the foot after coursing behind the __________.
- posterior tibial artery
- medial malleous
Tibial nerve innervates muscles in what 3 anatomical locations?
- posterior thigh
- posterior leg
- plantar foot
Does the tibial nerve branch? if so, into what and where?
-yes; into medial and lateral plantar nerves distal to the tarsal tunnel
What 4 muscles does the medial plantar nerve innervate in the sole of the foot?
- flexor digitorum brevis
- flexor hallucis brevis
- abductor hallucis
- first lumbrical
- lateral plantar nerve innervates the rest of the intrinsic foot muscles
Common and digital plantar branches of the medial plantar nerve innervate the _______________.
- skin of medial side of sole of the foot
- medial 3.5 digits
Common and digital plantar branches of the lateral plantar nerve innervate ______________.
-skin of the lateral side of the sole of the foot and the lateral 1.5 digits
Does the common fibular nerve innervate anything in the posterior thigh?
-yes, the short head of the biceps femoris
The __________ innervates the fibularis longus and brevis muscles in the lateral compartment of the leg
-superficial fibular nerve
Superficial fibular nerve innervation of the skin…
-innervates skin of the lateral leg and dorsum of the foot except for the first dorsal webbed space between the great toe and the second toe
The _____________ courses through the fibularis longus muscle and the anterior compartment of the lef with the anterior tibial artery.
-deep fibular nerve
What does the deep fibular nerve innervate?
- anterior compartment of leg
- tibialis anterior
- extensor hallucis longus
- extensor digitorum longus
- fibularis tertius muscles
- ___________
- extensor digitorum brevis and extensor hallucis brevis
Does the deep fibular nerve only innervate anterior compartment leg muscles?
- No, extensor digitorum brevis and extensor hallucis brevis muscles on dorsum of foot
- and skin of webbed space between great toe and 2nd toe
What does the sural nerve innervate?
-skin of the posterior leg and lateral aspect of the foot
Sural vein receives contributions from what nerves?
-tibial and common fibular
Sural nerve courses with the _________ in the posterior leg.
-small saphenous vein
Nerve to the quadratus femorus muscle
- L4, L5, S1
- enters gluteal region after passing through the greater sciatic foramen
- innervates quadratus femoris and inferior gemellus
Nerve to the obturator internus muscle
- L5, S1, and S2
- innervates superior gemellus and obturator internus
Posterior femoral cutaneous nerve
- innervates skin of posterior thigh and upper thigh
- only branch of lumbosacral plexus that has both anterior and posterior division fibers
Perforating cutaneous nerve
-innervates skin covering ischioanal fosal and gluteal region near anal canal