Lecture 25:Posterior Leg compartment and popliteal fossa Flashcards
margins of popliteal fossa
The superior margins are
* Biceps Femoris (laterally) and
Semimembranosus and Semitendinosus
(medially)
* The inferior borders
* Medial and lateral heads of Gastrocnemius
contens of popliteal fossa
- Popliteal artery and vein
- Tibial and Common Peroneal nerves
structures in the popliteal fossa from deep to superficial( starting from the knee joint)
- From deep to superficial:
- Knee joint capsule
- Popliteus (not examinable)
- Popliteal artery (most medial)
- Popliteal vein
- Tibial nerve (from sciatic N)
- The artery is the deepest structure in the
fossa (closest to the knee joint/ tibia and
femur).
what structure is likely to be affected 1st in knee dislocation?
popliteal a
sural nerve
- Tibial nerve has superficial branch that exits the popliteal fossa and travels down posterior aspect of leg on gastrocnemeus and becomes = sural nerve (also gets a branch from common peroneal nerve)
sural nerve is derived from 2 branches of common peroneal and tibial nerve
Small saphenous vein runs with sural nerve
great saphenous vein runs with…
saphenous nerve
leg compartments
Three compartments
Anterior, lateral and posterior
Two sub-compartments in posterior leg:
Superficial
Deep
Posterior Compartment
Muscles- Superficial
-gastrocnemius
-soleus
-plantaris
3 muscles, all innervated by tibial nerve
Gastrocnemius: O, I, Action, Nerve
O: 2 heads: medial and lateral femoral condyles.
I: calcaneus via Achilles tendon/calcaneal tendon
Action: Plantarflex ankle, flexes knee
Essential for Jumping and walking
Nerve: Tibial
Soleus: O, I, Action, Nerve
O: superior 1/3 post fibula also tibia
I: calcaneus via Achilles tendon/calcaneal tendon
Action: Plantarflex ankle. Walking
Nerve: Tibial
Plantaris: O, I, Action, Nerve
O: Superior to lateral head gastrocnemius on femur
I: medial side of tendon achilles( seperate from achilles tendon)
Action: Plantarflex ankle
Nerve: Tibial
Good as a tendon for tendon grafts
(70)% have one
Tibialis posterior: O, I, Action, Nerve
O: post tibia & fibula and interosseous membrane
I: Complex insertion into Navicula, medial cuneform + all bones of
mid and hind foot
Action: Plantarflexes ankle
Inverts foot
medial to axis of foot
Reinforces arches of foot
Nerve: tibial n
Flexor digitorum longus: O, I, Action, Nerve
O: middle half of tibia
I: distal phalanges of lateral 4 toes
Action: Flexes toes, plantarflexes ankle,
Reinforces the arches of the foot
Nerve: tibial
Flexor hallucis longus: O, I, Action, Nerve
O: inferior 2/3 of fibula and interosseous membrane
I:distal phalanx great toe
Action: Flexes great toe, plantarflexes ankle,
Reinforces the arches of the foot
Nerve: tibial
Popliteus: O, I, Action, Nerve
O: posterior tibia
I: lateral condyle femur, lateral meniscus
Action: Medially rotates tibia
Nerve: tibial
tarsal tunnel structures
T. Tibialis posterior
D Flexor digitorum longus
A Posterior tibial artery
V Vein
N. Tibial nerve
H. Flexor Hallucis longus
Tom Dick And Very Naughty Harry
Harry is naughty as tendon crossed
everyone in foot
most commonly ruptured tendon
The Achilles tendon is the most commonly injured tendon in the body
* Injuries can occur at the musculotendinous junction, within the tendon itself, or where it attaches to the calcaneus
- “Like kicked in back if leg”
- Audible snap
fabella
- The fabella (little bean) is a sesamoid bone located in the tendon of the lateral head of
gastrocnemius in some people. - It is often mistakenly interpreted as a fracture or loose body on a lateral xray
femoral nerve:
motor & cutaneous innervation
- Originate from L2, L3, L4
- Enter thigh under inguinal
ligament splits into multiple
muscular branches to anterior
thigh muscles - Also innervates skin on
anterior aspect of thigh via
anterior cutaneous nerve of
thigh - And **medial leg and foot via
saphenous nerve **(runs with
saphenous vein) - Supplies hip joint (in part)
obturator nerve:
motor & cutaneous innervation
- Originate from L2, L3, L4
- Enter thigh under through
the obturator foramen - Supplies muscular branches
to medial compartment
thigh muscles - Also innervates small area of
skin on medial thigh via
cutaneous branch
sciatic nerve(tibial nerve):
motor & cutaneous innervation
- L4-S4 LS plexus
- Sciatic nerve has 2 branches:
- Tibial nerve
- Common Peroneal nerve
- The Tibial nerve supplies all the muscles of the posterior compartments (thigh and leg) before passing posterior to the medial malleolus.
- In the sole of the foot Medial and Lateral Plantar nerves (Cutaneous to sole of foot and motor)
- A branch of the Tibial nerve and Common Peroneal nerve form the Sural nerve.
- The Sural nerve supplies the skin to the lateral and posterior sides of the inferior leg and heel.
sciatic nerve( common peroneal nerve):
motor & cutaneous innervation
- The Common Peroneal Nerve divides into:
- Deep Peroneal nerve
- Superficial Peroneal nerve
- The Deep Peroneal nerve supplies anterior compartment, the muscles of the dorsum of the foot, and then becomes cutaneous to the first webspace
- The Superficial Peroneal nerve enters the lateral compartment and supplies both the muscles.
- This nerve then continues as a cutaneous nerve, supplying the skin of the anterior leg and most of the dorsum of the foot.
