MSK Exam 2 Flashcards
Between what 2 anatomical points does the patellar tendon pass?
From the apex of the patella to the tuberosity of the tibia
Where does the oblique popliteal ligament pass and what does it check?
From the lateral femur to the posterior head of the tibia; checks extensions
Where does the arcuate popliteal ligament pass?
From the lateral condyle of the femur to the head of the fibula
Where does the ACL pass?
From the font of the intercondylar eminence to the medial surface of the lateral femoral condyle posteriorly
What does the ACL check?
Extension and anterior slipping of the tibia on the femur
Where does the PCL pass?
From the posterior intercondylar fossa and the posterior end of the lateral meniscus to the lateral surface of the medial femoral condyle anteriorly
What does the PCL check?
Checks flexion and posterior slippage of the tibia on the femur
Where does the ACL most commonly tear?
The mid portion of the ligament (origin and insertion are much broader)
What test performed in clinic can verify an ACL tear?
An anterior drawer test– if positive, the torn ACL will permit the tibia to slide anteriorly on the femur
To what other structure is the medial meniscus firmly attached?
The MCL
What is the role of the medial meniscus?
Deepens the medial tibial condyle
What is the role of the lateral meniscus?
Deepens the lateral tibial condyle
What is the medial collateral ligament?
Thickened portion of the articular capsule from the medial side of the medial femoral condyle to the medial condyle and body of the tibia; keeps knee STABLE as it moves through its full arc of motion
What is the lateral collateral ligament?
From the back of the lateral femoral condyle to the lateral side of the head of the fibula; keeps knee stable as it moves through its full arc of motion
What is the mechanism of injury to the MCL?
Forced abduction of the tibia on the femur (knee hit from lateral side; MCL is stretched)
What is the mechanism of injury to the LCL?
Forced adduction of the tibia on the femur ( a force pushing the knee from the medial/inner side of the joint causing stress on the outside)
Which of the menisci is more commonly involved in tears and why?
Medial meniscus.
The lateral meniscus does not tear readily because it is more mobile.
What muscles are in the posterior compartment of the thigh? What are they commonly called as a group?
- semimembranosus
- semitendonosus
- biceps femoris
commonly called “hamstrings”
What nerve passes deep to the long head of the biceps femoris muscle?
The sciatic nerve
What is the proximal attachment of the long head of the biceps femoris?
the ischial tuberosity
What is the distal attachment of the long head of the biceps femoris?
the head of the fibula
What nerve innervates the long head of the biceps femoris?
tibial division of the sciatic nerve
What is the proximal attachment of the short head of the biceps femoris?
Linea aspera of the femur
What is the distal attachment of the short head of the biceps femoris?
The tendon of the short head joins the tendon of the long head to insert into the head of the fibula
What is the action of the biceps femoris muscle?
Extends the thigh and FLEXES the leg
What innervates the short head of the biceps femoris?
Common fibular division of the sciatic nerve
What is the proximal attachment of the semitendinosus?
ischial tuberosity
What is the distal attachment of the semitendonosis?
medial surface of the superior part of the tibia
What innervates the semitendonosus?
tibial division of the sciatic nerve
what is the proximal attachment of the semimembranosus?
ischial tuberosity
What is the distal attachment of the semimembranosus?
posterior part of the medial condyle of the tibia
What is the action of the semitendonosus?
extends the thigh and flexes the leg
What is the action of the semimembranosus?
Extends the thigh and flexes the leg
What innervates the semimembranosus?
tibial division of the sciatic nerve
What are the borders of the popliteal fossa?
Superolateral–> biceps femoris
Superomedial–> semintendonosus and semimembranosus muscles
Inferolateral/inferomedial–> the 2 heads of the gastrocnemius
Posterior–> skin and deep popliteal fascia
Anterior–> popliteal surface of femur
Where does the sciatic nerve branch into the tibial and common fibular nerves?
At the superior border of the popliteal fossa
What is the adductor hiatus?
An opening in the adductor magnus between its hamstring and adductor parts; serves as the terminal end of the adductor canal
Where does the common fibular nerve run?
Parallels the biceps femoris tendon and passes superficial to the lateral head of the gastrocnemius muscle
Where does the tibial nerve pass?
Deep to the plantaris and gastrocnemius muscle at the inferior border of the popliteal fossa
What lies deep to the tibial nerve?
The popliteal artery and vein
What are the superior lateral and superior medial genicular arteries?
Branches of the popliteal artery that participate in the formation of the arterial anastomoses around the knee joint (genicular anastamosis). Located deep in the popliteal fossa.
Distally, where does the popliteal artery pass?
Deep to the plantaris and gastrocnemius muscles
What does the genicular anastomosis receive contributions from?
Femoral artery, lateral circumflex artery and anterior tibial artery
Where is the popliteus muscle located?
Deep to the popliteal artery/vein
What structure on the medial side of the knee is composed of the convergence of 3 muscle tendons?
Pes Anserinus, made up by the tendons of the sartorius, gracilis and semitendinosus
Where does the posterior compartment of the leg lie?
Posterior to the interosseous membrane
What divides the muscles of the posterior compartment of the leg into superficial and deep groups?
A transverse intermuscular septum
What 3 muscles make up the superficial posterior group of the leg?
Gastrocnemius, soleus and plantaris
What is the group action of the superficial posterior muscle group?
Flexion of the foot
What 4 muscles make up the deep posterior group of the leg?
- popliteus
- tibialis posterior
- flexor digitorum longus
- flexor hallucis longus
What is the shared action of the deep posterior muscle group of the leg?
Inversion of the foot, plantar flexion of the foot, and flexion of the toes
What nerve innervates both the superficial and deep posterior muscle groups of the leg?
The tibial nerve
What is the most superficial muscle of the posterior compartment of the leg?
Gastrocnemius muscle
What are the proximal attachments of the gastrocnemius muscle?
The femoral condyles
What is the distal attachment of the gastrocnemius muscle?
Calcaneal tuberosity by way of the calcaneal (Achilles tendon)
What is the action of the gastrocnemius?
plantar flexion
What muscle is deep to the gastrocnemius muscle?
The soleus
What is the proximal attachment of the soleus muscle?
Soleal line of the tibia and the head of the fibula
What is the distal attachment of the soleus muscle?
The calcaneal tendon
What is the action of the soleus muscle?
Plantar flexion of the foot
What is the proximal attachment of the plantaris muscle?
Lateral supracondylar line of the femur
Where does the tendon of the plantaris muscle course?
Proximal part of leg: courses between the gastrocnemius and soleus muscles
Distal part of the leg: may be seen on the medial side of the tendon of the gastrocnemius muscle
What is the attachment of the tendon of the plantaris muscle?
Joins the calcaneal tendon and ultimately attaches to the calcaneus
What is the action of the plantaris muscle?
Plantar flexion of the foot/weak flexion of the knee
Where to the tibial nerve, posterior tibial artery and posterior tibial vein exit the popliteal fossa?
By passing deep to the tedinous arch of the soleus. They course distally in the transverse intramuscular septum that separates the superficial posterior muscle group
At the inferior border of the popliteus muscle, what does the popliteal artery bifurcate into?
- posterior tibial artery
2. anterior tibial artery
What is the proximal attachment of the popliteus muscle?
lateral condyle of the femur
What is the distal attachment of the popliteus muscle?
posterior surface of the proximal tibia
What is the action of the popliteus muscle?
Rotates the femur on the tibia to unlock the extended knee. Also a weak flexor of the leg
What is the proximal attachment of the flexor hallucis longus?
Posterior surface of the fibula
What is the distal attachment of the flexor hallucis longus?
Base of the distal phalanx of the great toe (hallux)
What is the innervation of the flexor hallucis longus?
Tibial nerve (S2, S3)
What is the action of the flexor hallucis longus?
Flexes great toe at all joints; weakly plantar flexes ankle; supports medial longitudinal arch of the foot
What is the proximal attachment of the flexor digitorum longus?
Posterior surface of the tibia
What is the distal attachment of the flexor digitorum longus?
Bases of distal plalanges of the lateral 4 digits
What innervates the flexor digitorum longus?
Tibial nerve (S2,3)
What is the main action of the flexor digitorum longus?
Flexes lateral four digits; plantar flexes ankle; supports longitudinal arch
What is the proximal attachment of the tibialis posterior?
Posterior surface of the tibia and fibula
What is the distal attachment of the tibialis posterior?
Plantar surface of several tarsal
What is the innervation of the tibialis posterior?
Tibial nerve (L4,L5)
What is the action of the tibialis posterior?
Plantarflexes ankle; inverts foot
Where do the long tendons and principle vessels/nerves from the posterior compartment of the leg pass?
Posterior to the medial malleolus, deep to the flexor rtinuaculum to enter the sole of the foot
What do the TIBIALIS muscles do?
invert the foot
What the the fibularis (perineal) muscles do?
evert the foot
What 2 arteries are in the posterior compartment of the leg?
Posterior tibial artery and the fibular artery
What does the posterior tibial artery divide into?
Medial and lateral plantar arteries
What artery does the fibular artery come off of near its origin?
Posterior tibial artery
What causes foot drop?
Injury to the common fibular nerve, often as a result of fractures of the fibula, or pressure from casts or splints.
Where does sensory loss occur in foot drop?
Down the anterior and lateral sides of the leg and dorsum of foot and toes
Where to the muscles of the dorsum (extensor digitorum brevis and extensor hallucis brevis) of the foot originate?
Calcaneus
What is the nerve supply of the muscles of the dorsum of the foot (extensor digitorum brevis and extensor hallucis brevis)?
Deep fibular nerve
What is the distal attachment of the extensor digitorum brevis?
Middle plalange of lateral 4 toes
What is the main action(s) of the extensor digitorum brevis?
Aids the extensor digitorum longus in extending the 4 medial toes at the metatarsophalangeal (MP) and interphalangeal (IP) joints
What is the distal attachment of the extensor hallucis brevis?
Dorsal aspect of base of proximal phalanx of great toe (digit 1)
What is the main action(s) of the extensor hallucis longus?
Aids extensor hallucis longus in extending the great toe at the MP joint
What is the anterior tibial artery when it passes the ankle joint?
Dorsalis pedis
What does the dorsalis pedis branch into when it ends?
Arcuate and larger deep plantar artery
Where can the dorsalis pedis artery be palpated?
Lateral to the extensor hallucis longus tendon
What is the role of the intrinsic muscles of the foot?
Specialized to maintain the arches of the foot so we can stand on uneven surfaces
What is the arterial supply to the plantar surface of the foot?
From arteries derived from the posterior tibial artery (medial and lateral plantar arteries)
What is the axis of reference for abduction and adduction of the foot?
The second toe
What are the muslces of the first layer of the foot?
Flexor digitorum brevis, abductor hallucis, and abductor digiti minimi
What is the proximal attachment of the 3 muscles of the first layer of the foot (Flexor digitorum brevis, abductor hallucis, and abductor digit minimi)?
Calcaneal tuberosity
What is the distal attachment of the flexor digitorum brevis?
Middles phalanges of the lateral 4 toes
What is the innervation of the flexor digitorum brevis?
Medial plantar nerve
What is the main action of the flexor digitorum brevis?
Flexes the lateral 4 digits
What is the distal attachment of the abductor hallucis?
Medial side of the proximal phalanx of the great toe
What is the innervation of the abductor hallucis?
Medial plantar nerve
What is the main action of the abductor hallucis?
Abduct the great toe
What is the distal attachment of the abductor digiti minimi?
Lateral side of the proximal phalanx of the 5th toe
What innervates the abductor digiti minimi?
Lateral plantar nerve
What is the action of the abductor digiti minimi?
Abducts the 5th toe
What are the muscles of the second layer of the foot?
Quadratus plantae and Lumbricals
What is the proximal attachment of the quadratus plantae?
Calcaneous
What is the distal attachment of the quadratus plantae?
Tendon of the flexor digitorum longus muscle
What is the innervation of the quadratus plantae?
Lateral plantar nerve
What is the main action of the quadratus plantae?
Assists the flexor digitorum longus muscle in flexing the lateral 4 digits
What is the proximal attachment of the lumbricals?
Tendons of the flexor digitorum longus
What is the distal attachment of the lumbicals?
Extensor expansions of the lateral 4 toes
What is the innervation of the lumbricals
Medial plantar nerve- medial 1
Lateral plantar nerve- lateral 3
What is the action of the lumbricals?
Flex proximal phalanges, extend middle and distal phalanges of the lateral 4 digits
What are the 3 muscles of the third layer of the foot?
Flexor hallucis brevis, adductor hallucis (transverse and oblique heads), and flexor digiti minimi
What is the proximal attachment of the flexor hallucis brevis?
Lateral tarsal bones
What is the distal attachment of the flexor hallucis brevis?
Proximal phalanx of the great toe
What is the proximal attachment of the adductor hallucis? (transverse and oblique heads)
transverse head: plantar ligaments of metatarsophalangeal joints
bases of metatarsals 2-4- oblique head
What is the distal attachment of the adductor hallucis?
Lateral side of the proximal phalanx of the great toe
What is the innervation of the flexor hallucis brevis?
Medial plantar nerve
What is the main action of the flexor hallucis brevis?
Flexes the great toe
What is the innervation of the adductor hallucis?
Deep branch of the lateral plantar nerve
What is the main action of the adductor hallucis?
Adducts the great toe (moves it TOWARDS the second toe)
What is the proximal attachment of the flexor digiti minimi?
5th metatarsal bone
What is the distal attachment of the flexor digiti minimi?
Proximal phalanx of the 5th toe
What is the innervation of the flexor digiti minimi?
Superficial branch of the lateral plantar nerve
What is the main action of the flexor digiti minimi?
Flexes the 5th toe
What is genu recurvatum?
The knee is hyperextended such that the lower extremity curves
Where does the small saphenous vein terminate?
The popliteal fossa
What are the contents of the popliteal fossa?
- Termination of small saphenous vein
- Popliteal artery and vein
- Tibial and common fibular nerves
- Posterior cutaneous nerve of the thigh
- Popliteal lymph nodes and lymphatic vessels
What is the proximal attachment of the popliteus muscle?
Lateral condyle of femur
What is the distal attachment of the popliteus?
Posterior surface of tibia
What is the innervation of the popliteus?
Tibial nerve (L4,5,S1)
What is the main action of the popliteus muscle?
Weakly flexes the knee
What is the proximal attachment of the plantaris muscle?
Lateral supracondylar line of femur
What is the distal attachment of the plantaris muscle?
Posterior surface of calcaneus via calcaneal tendon
What is the innervation of the plantaris muscle?
Tibial nerve (S1,2)
What is the main action of the plantaris muscle?
Weakly assists gastrocnemius muscle in plantar flexing the ankle
What is the action of the talocrural (ankle) joint?
Dorsiflexion and plantarflexion
What is the main action of the subtalar (talocalcaneal) joint?
Gliding (inversion and eversion)
What is the most common ankle sprain?
with foot in plantar position, inverted, and abducted. strain is focused on lateral ligament of the ankle joint
What causes Pott’s fracture-dislocation of the ankle?
When the foot is forcibly everted, it pulls on the extremely strong deltoid ligament/can pull the medial malleolus off the tibia, causing the talus to move laterally shearing off the lateral malleolus or breaking the fibula superior to the inferior tibiofibular joint
What are the muscles of the lateral compartment of the leg?
Fibularis longus and fibularis brevis
What is the proximal attachment of the fibularis longus?
Head and lateral surface of the fibula
What is the distal attachment of fibularis longus?
Base of 1st metatarsal and medial cuneiform
What is the innervation of the fibularis longus?
superficial fibular nerve (L5, S1, S2)
What is the main action of the fibularis longus?
Everts foot and weakly plantar flexes
What is the proximal attachment of the fibularis brevis?
inferior lateral surface of the fibula
What is the distal attachment of the fibularis brevis?
Dorsal surface of the tuberosity on lateral side of base of the 5th metatarsal
What innervates the fibularis brevis?
Superficial fibular nerve (L5,S1,S2)
Main action of fibularis brevis?
Everts foot and weakly plantarflexes
What does the common fibular nerve branch into?
Superficial and deep fibular nerves
What does the superficial fibular nerve supply?
Lateral compartment of the leg muscles, skin on distal third of anterior surface of leg and dorsu of foot
What does the deep fibular nerve supply?
The anterior compartment of the leg muscles; skin of first interdigital cleft on the dorsum of the foot
From what does the anterior tibial artery originate?
Popliteal artery
What does the anterior tibial artery supply?
The anterior compartment of the leg