Lecture 3.5 - Popliteal Fossa and Leg Flashcards
What is the popliteal fossa and its boundaries?
- diamond-shaped space posterior to the knee
boundaries: - suprior lateral: biceps femoris
- superior medial: semimembranosus, semitendinosus
- inferior: medial/lateral heads of the gastrocnemius
What blood vessels and nerves does the popliteal fossa contain?
- popliteal artery/vein
- tibial nerve
- common fibular nerve
- small saphenous vein
What bones are in the leg (crus)? What are its muscle groups?
Bones: - tibia (supports body weight) - fibula (stability to ankle joint) Muscles: - anterior muscles (4) - lateral muscles (2) - posterior muscles (7)
What kind of fascia is in the leg?
- deep fascia = crural fascia
- continuous with fascia lata of thigh
- crural fascia separates leg into 4 regions
What are the actions of the anterior leg muscles? Lateral leg muscles? Posterior leg muscles?
Anterior muscles:
- dorsiflexion (extension) of foot and/or toes
Lateral muscles:
- eversion and plantarflexion of foot
Posterior muscles:
- plantarflexion (flexion) of foot and/or toes
- inversion of foot
Which muscles are the anterior crural compartment? What do they do? What is their innervation?
- tibialis anterior, extensor hallucis/digitorum longus, fibularis tertius
- they dorsiflex the foot and extend the toes
- supplied by deep fibular nerve
Which muscles are the lateral crural compartment? What do they do? What is their innervation?
- fibularis longus/brevis
- they evert the foot
- supplied by the superficial fibular nerve
Which muscles are the posterior crural compartment? What do they do? What is their innervation?
- superficial: triceps surae, plantaris
- deep: tibialis posterior, flexor digitorum longus, flexor hallucis longus
- they plantarflex the foot and flex the toes
- supplied by tibial nerve
Tibialis Anterior (OINA)
O: lateral tibial condyle, lateral surface of tibia, and interosseous membrane
I: medial cuneiform and first metatarsal
N: deep fibular nerve
A: dorsiflexes and inverts foot
What is Foot-Drop?
paralysis of tibialis anterior causes foot drip de to injury to common fibular nerve or its deep branch
What are shin-splints?
painful swelling of anterior compartment muscles after vigorous or lengthy exercise
Extensor Hallucis Longus (OINA)
O: middle anterior fibula and interosseous membrane
I: distal phalanx of hallux
N: deep fibular nerve
A: dorsiflex foot; extends hallux
Extensor Digitorum Longus (OINA)
O: lateral tibial condyle, proximal 2/3rds of fibula and interosseous membrane
I: middle and distal phalanges of lateral 4 digits
N: deep fibular nerve
A: dorsiflexes and everts foot; extends lateral 4 digits
Fibularis Tertius (OINA)
O: lower fibula and interosseous membrane
I: base of 5th metatarsal
N: deep fibular nerve
A: dorsiflexes and everts foot
Fibularis Longus (OINA)
O: head and superior lateral fibula
I: 1st metatarsal and medial cineiform
N: superficial fibular nerve
A: plarflexes and everts foot
Fibularis Brevis (OINA)
O: inferior lateral fibula
I: tuberosity of 5th metatarsal
N: superficial fibular nerve
A: plantarflexes and everts foot
How can the 5th metatarsal be avulsed traumatically?
during violent eversion of the foot, the tubercles of the 5th metatarsal bone can be avulsed
What are the deep and superficial muscles int he posterior compartment?
Deep: - popliteus - flexor hallucis longus - tibialis posterior - flexor digitorum longus Superficial: - gastrocnemius - soleus - plantaris
Gastrocnemius (OINA)
O: lateral and medial femoral condyles
I: posterior calcaneus
N: tibial nerve
A: flexes knee; plantarflexes foot
What do the superficial posterior muscles do?
help in walking, dancing, and standing on the toes
What is tennis leg?
painful calf injury due to tearing of medial belly of gastrocnemius
Soleus (OINA)
O: fibular head and soleal line of tibia
I: posterior calcaneus
N: tibial nerve
A: plantarflexes foot
What does constantly wearing high heels do to your muscels?
women you continuously wear high heel shoes have shorter triceps surae and can experience transitory calf pain when they switch to flats
How is the calcaneal tendon ruptured?
occurs in old age, or playing squash, or at the start of a 100 meter dash, due to ischemia
Plantaris (OINA)
O: inferior lateral supracondylar line
I: posterior calcaneus
N: tibial nerve
A: weakly assits gastrocnemius
What is special about plantaris tendon?
its tendon can be removed and used to repair other damaged tendon
Popliteus (OINA)
O: lateral epicondyle of femur
I: superior posterior tibia
N: tibial nerve
A: flexes knee and rotates knee joint; unlocks knee at the beginning of flexion of the fully extended knee
What are the actions of the popliteus?
- rotation is about 5 degrees
- when the knee is fully extended it is locked by the medial rotation of femur on tibia around a tight ACL
- popliteus unlocks the knee by laterally rotating the femur ont he weight-bearing tibial allowing relaxation of the ligaments and then flexion
- during this movement it also causes the lateral meniscus to be pulled out of the way of injury
What are the characteristics of the deep posterior muscles?
- three deep posterior leg muscles
- all span the ankle joint
- two of them also flex the toes
Flexor Hallucis Longus (OINA)
O: inferior 2/3 of posterior fibula; interosseous membrane
I: distal phalanx of hallux
N: tibial nerve
A: flexes hallus and plantarflexes foot
How does the flexor hallucis longus, tibialis posterior, and flexor digitorum longus help in running?
Flexor digitorum/hallucis longus and tibialis help to maintain the medial longitudinal arch of foot.
Flexor hallucis longus is the “toe off” muscle during walking and running.
Flexor digitorum longus gives foot a grip while walking and running
Tibialis Posterior (OINA)
O: interosseous membrane; posterior tibia and fibula
I: navicular, cuneiform, cuboid, and 2-4 metatarsals
N: tibial nerve
A: plantarflexes and inverts foot
Flexor Digitorum Longus (OIN)A
O: middle posterior tibia
I: distal phalanges of lateral 4 digits
N: tibial nerve
A: flexes lateral 4 digits; plantarflexes foot
What are the nerves of the posterior leg? What is their pathways and symptoms of damage?
Tibial nerve continues across ankle
- if damaged: weak plantarflexion; plantarflexion is accompined by eversion; loss of toe flexion
Common fibular nerve winds around head of fibula
- very frequently damaged
- if damaged: loss of eversion and dorsiflexion
What are the nerves of the lateral and anterior leg? What is their pathways and symptoms of damage?
Common fibular nerve: Superficial fibular (lateral) - damage results in weak eversion Deep fibular (anterior) - damage results in loss of dorsiflexion (foot drop)
What are the arteries of the knee and leg?
- “genu” means “knee” in Latin
- after giving off genicular arteries, popliteal artery divides into:
- anterior tibial artery (goes to anterior compartment)
- posterior tibial artery (stays in posterior compartment)
- – fibular artery
