Leg Flashcards
What are the muscles of the Posterior Compartment?
- Gastrocnemius
- Soleus
- Plantaris
- Popliteus
- Flexor Hallucis Longus (FHL)
- Flexor Digitiorum Longus (FDL)
- Tibialis Posterior
What divides the superficial and deep compartments of the posterior compartment?
Transverse intermuscular septum
What makes up the triceps surae?
Gastronemuius and soleus mm. collectively make it up… generating majority of plantar flexion force.
What is the Achilles tendon also called?
Calcaneal tendon
- most powerful and and thickest tendon in the body
- continuation of aponeurosis formed by gastrocnemius and soles mm.
Gastrocnemius
O: Lateral head - popliteal surface, lateral aspect of lateral condyle of femur. Medial head - popliteal surface of femur superior to medial condyle.
I: Posterior surface of calcaneus via calcaneal tendon.
A: Plantarflexion with extended knee; leg flexion
N: Tibial n. (S1,S2)
B: Popliteal a.
* functions most effectively with extended knee
*incapable of producing plantar flexion when knee is fully flexed
Soleus
O: Posterior aspect of head and superior 1/4 of posterior surface of fibula: soleal line, middle 1/3 of medial border of tibia.
I: Posterior surface of clacaneus via calcaneal tendon.
A: Plantarflexion independent of position of knee.
N: Tibial n. (S1,S2)
B: Posterior tibial aa.
*Tendinous arch of soleus: continuous proximal attachment, shape like an inverted U
*workhorse of plantar flexion
*accessory soleus present 3% of the time (lies medial to calcaneal tendon)
Plantaris
O: Inferior end of lateral supracondylar line of femur, oblique popliteal l.
I: posterior surface of calcaneus via calcaneal tendon.
A: Weak plantarflexion
N: Tibial n. (S1, S2)
B: Popliteal a.
*absent 5-10%
*short belly, long tendon that is often mistaken for a nerve “freshmen’s nerve”
*tendon often used for grafting
*considered an organ proprioception for large plantar flexors (high density of muscle spindles)
Popliteus
O: Lateral surface of lateral condyle of femur
I: posterior surface of tibia, superior to soleal line
A: Weak flexion of leg; unlocks knee by rotating femur 5 degrees on fixed tibia; medially rotates tibia of unplanted limb
N: Tibial n. (L4, L5, S1)
B: popliteal a.
*tendon emerges from joint capsule of knee
*forms inferior part of floor popliteal fossa
Flexor Hallucis Longus (FHL)
O: inferior 2/3 of posterior surface of fibula; inferior part of interosseous membrane
I: Base of distal phalanx of great toe
A: flexion of great toe at all joints; weak plantarflexion
N: Tibial n. (S2, S3)
B: Fibular a.
*referred to as “Harry”
*powerful flexor of all joints of great toe (toe off)
*tendon passes posterior to medial malleolus and inferior to sustentaculum tali
*Then runs between two sesamoid bones in tendons of flexor hallucis brevis m.
Flexor Digitorum Longus (FDL)
O: Medial part of posterior surface of tibia inferior to soleal line
I: Base of distal phalanges of lateral 4 digits
A: Flexion of lateral 4 digits; plantarflexion
N: Tibial n. (S2, S3)
B: Posterior tibial a.
*referred to as “Dick”
*tendon crosses over TP superior to medial malleoulus.
*tendon passes posterior to medial malleoulus
*Then passes superficial to tendon to FHL in sole of foot
*Direction of pull realigned by quadrates plantae m.
Tibialis posterior
O: Interosseous membrane; posterior surface tibia inferior to soleal line; posterior surface fibula
I: Tuberosity of navicular, cuneiform, cuboid, sustentaculum talk and bases of 2nd - 4th metatarsals.
A: Plantarflexion and inversion
N: Tibial n. (L4, L5)
B: Posterior tibial a.
*reffered to as “Tom”
*between FHL and FDL
*tendon passes immediately posterior to medial malleoulus
*synergist to TA for inversion
*primary role is to support medial longitudinal arch
What are the muscles of Lateral compartment of leg?
- Fibularis Longus (FL)
- Fibularis Brevis (FB)
Fibularis Longus (FL)
O: Head and superior 2/3 lateral surface of fibula
I: Base of 1st metatarsal and medial cuneiform
A: Eversion and weak plantarflexion
N: Superficial fibular n. (L5, S1, S2)
B: Perforating branches of fibular and anterior tibial aa.
Fibularis Brevis (FB)
O: Inferior 2/3 of lateral surface of fibula
I: Tuberoisity of base of 5th metatarsal
A: Eversion and weak plantarflexion
N: Superficial fibular n. ( L5, S1, S2)
B: Performing branches of fibular and anterior tibial aa.
What is the vasculature of lateral compartment of leg?
- no artery courses through lateral compartment
- Supplied by: perforating branches from anterior tibial a. (superior part). Perforating branches from fibular a. (inferior part).
What is the innervation of lateral compartment?
- Superficial fibular n. : terminal branch of common fibular n. terminating as -> medial dorsal cutaneous n., intermediate dorsal cutaneous n.
- Lateral sural cutaneous n. : from common fibular n. supplying skin of upper lateral leg.
What are the muscles of Anterior Compartment?
- Tibialis Anterior (TA)
- Extensor Digitorum Longus (EDL)
- Fibularis Tertius
- Extensor Hallucis Longus (EHL)
Tibialis Anterior (TA)
O: lateral condyle and superior 1/2 of lateral surface of tibia and interosseous membrane
I: medial inferior surfaces of medial cuneiform and bad of 1st metatarsal
A: Dorisiflexion and inversion
N: Deep fibular (peroneal) n. (L4, L5)
B: Anterior tibial a.
*most medial and superficial dorsiflexor
*lies agains lateral surface of tibia
*tendon has its own synodal sheath
*strongest dorsiflexor
Extensor Digitorum Longus (EDL)
O: Lateral condyle of tibia and superior 3/4 of medial surface of fibula and interosseous membrane.
I: middle and distal phalanges of lateral 4 digits
A: Extension of lateral 4 digits and dorsiflexion
N: deep fibular n. (L4, L5)
B: anterior tibial a.
*forms 4tt. that attach to phalanges
*has common synovial sheath with FT
*each tendon forms extensor expansion (over proximal phalanx of toe)
Fibularis Tertius
O: inferior 1/3 of anterior surface of fibula and interosseous membrane
I: dorsum of base of 5th metatarsal
A: Dorsiflexion and aids in eversion
N: deep fibular n. (L4, L5)
B: anterior tibial a.
*separated part of EDL (continuous proximally and separate tendon distally)
*not always present
Extensor Hallicus Longus (EHL)
O: middle part of anterior surface of fibula and interosseous membrane
I: base of distal phalanx of great toe (hallux)
A: extension of great toe and dorsiflexion
N: Deep fibular n. (L4, L5)
B: anterior tibial a.
*deep fibular n. and anterior tibial a. found between EHL and TA
What is a terminal branch of popliteal a. ?
Posterior tibial a.
What does the posterior tibial a. terminate as?
medial and lateral plantar aa.
The fibular artery is from what a.?
from posterior tibial a.
Where does the saphenous v. start?
Where does it drain?
- arises from dorsal venous arch
- drains into popliteal v.
Tibial roots from what?
Branches from what?
- L4-L5
- Branches from the sciatic nerve, larger of two terminal branches of sciatic n.
What forms the sural n.?
-medial sural cutanoues n. joins with aural communicating branch of common fibular n.
Where does the tibial n. travel?
What does it supply?
- passes between 2 heads of gstrocnemius m. and then passes posterior to medial malleolus between tt. of FDL and FHL
- supplies all m. in the posterior compartment of the leg.
What does the tibial n. terminate as?
- medial plantar n.
- lateral plantar n.
Where does the small saphenous v. arise?
What does it drain into?
Where does it ascend?
- arises from lateral side of dorsal venous arch
- ascends posterior to lateral malleolus and continuous upward between heads of gastrocnemius m.
- drains into popliteal v.
