Lecture 24: Posterior Leg and Popliteal fossa

Question 1

What are the 4 boundaries of the Popliteal fossa (diamond) + floor

Answer 1

Superolateral: Biceps femoris
Superomedial: semitendinosus+ semimembranosus
Inferior: medial + lateral heads of gastrocnemius
Floor: capsule of knee joint and popliteus muscle(when flexed)

Question 2

What are the contents of popliteal fossa from deepest and most medial to less medial

Answer 2

Popliteal artery, then popliteal vein, then tibial nerve then common fibula/peroneal nerve which lies on the lateral border of biceps femoris, exiting

Question 3

What are the two superficial vessels that lie on top of the deep fascia of the posterior leg from the popliteal fossa

Answer 3

The small saphenous vein from femoral vein which runs with the Sural nerve. This nerve travels down the posterior comp of the leg between the two heads of gastrocnemius and is made from the Tibial nerve and the common peroneal nerve. It supplies cutaneous sensation to the posterior and lateral calf + heel.

Question 4

What are the vessels and nerves in the posterior leg and their order of position from med to lat, where do they end up in the foot.

Answer 4

Posterior tibial vein then post tibial Artery which sits between superficial and deep muscles in the posterior leg compartment, then Tibial nerve. They all run in the posterior compartment before eventually passing posterior to the medial malleolus. In the sole of the foot the Post tib artery and Tib nerve divide into Medial and Lateral plantar branches.

Question 5

Where is the Tarsal tunnel and what are its contents superior to inferior

Answer 5

Tarsal tunnel is a space for tendons and vessels on the medial side of the foot between the medial malleolus and the calcaneous. 
contents: Tibial posterior tendon
flex Digitorum longus 
post. tib. Artery 
post tib. Vein
tib. Nerve 
flex Hallucis longus 
(TDavnH)

Question 6

What are the three muscles of the superficial compartment of the posterior leg (sup to deep) and what makes the Triceps surae

Answer 6

Gastrocnemius, Plantaris, Soleus,

Triceps Surae: 2 heads of gastroc + soleus

Question 7

What is the common innervation and action of all the muscles in the posterior compartment of the leg

Answer 7

Tibial nerve. They all plantar flex the ankle - except popliteus

Question 8

What is the origin and insertion, special action other than common action of post compartment of leg of Gastrocnemius

Answer 8

O: Medial and Lateral condyle of the femur
I: Post calcaneus via Achilles Tendon
Special: Flexes knee bc crosses knee joint

Question 9

What is the origin and insertion, special action other than common action of post compartment of leg of Soleus

Answer 9

O: Superior 1/3 fibula and soleal line of tibia
I: Post calcaneus via Achilles Tendon
no special

Question 10

What is the origin and insertion, special action other than common action of post compartment of leg of Plantaris

Answer 10

O: Superior to the lateral head of gastrocnemius on the femur
I: Medial side of the Achilles tendon
no special (remnant muscle)

Question 11

What are the 4 muscles of the deep posterior comp of the leg (med to lat+ comparable superficial/ deepness)

Answer 11

Superiorly is popliteus

most medial is Flexor digitorum longus then most deep: Tibialis posterior then most lateral is Flexor Hallucis longus

Question 12

What is the origin and insertion, special action other than common action of post compartment of leg of Tibialis Posterior

Answer 12

O: Posterior tibia, fibula and interosseus membrane
I: Navicular with slips to all mid and hind foot bones
Special: Inverts the foot and reinforces the arch of the foot

Question 13

What is the origin and insertion, special action other than common action of post compartment of leg of Flexor Digitorum Longus

Answer 13

O: Middle half of the tibia
I: Distal phalanges of the lateral 4 toes under the foot
Special: Flexes the toes

Question 14

What is the origin and insertion, special action other than common action of post compartment of leg of Flexor Hallucis Longus

Answer 14

O: Inferior 2/3 of the fibula and the interosseus membrane
I: Distal phalanx of the great toe under the foot
Special: flexes great toe

Question 15

What is the origin and insertion, special action other than common action of post compartment of leg of Popliteus

Answer 15

O: Lateral condyle of femur and lateral meniscus
I: Posterior tibia superior to the soleal line
Special: It does not plantar flex the ankle, it medially rotates the tibia and unlocks the knee when walking

Question 16

What are the 4 good places to find a pulse in the lower limb

Answer 16

1. Femoral artery up in the femoral triangle
2. Popliteal artery at the popliteal fossa
3. Post Tib artery at Tarsal tunnel
4. Dorsalis Pedis artery at the 2nd digit of foot

Question 17

What is the clinical presentation of Achilles tendon injuries, where is the common site of injury and treatments

Answer 17

Presents as inability to push off due to loss of plantar flexion. More likely at where it attaches at the calcaneous but can also happen at the musculotendinous junction. Treatment can be sutured back together or it can be cast in plantar flexion to promote healing

Question 18

What is the fabella

Answer 18

A sesamoid bone located in the tendon of the lateral head of the gastrocnemius in some people sometimes mistaken for loose body or fracture in xray