The Leg Flashcards
What are the boarders of the popliteal fossa?
Superiorly - Biceps femoris, semimembranous and the tendon of semitendinosus.
Inferiorly - Lateral and medial heads of gastrocnemius.
Floor - femur
How does the adductor canal open into popliteal fossa?
It opens at the adductor hiatus in adductor magnus at the adductor tubercle.
What are the contents of the popliteal fossa?
- Popliteal artery and vein with their branches and tributaries.
- Tibial nerve.
- Common fibular nerve.
- Posterior cutaneous nerve of the thigh.
- Terminal part of small saphenous vein.
- Lymph nodes.
- Fat.
When is the popliteal artery at risk? and why
Dislocation of the knee or a supracondylar fracture of femur. This is because the popliteal artery lies on the femur.
What is the role of popliteus?
It laterally rotates the femur when it contracts, unlocking the knee.
What are the attachments of poplitus?
Posterior surface of tibia to the lateral condyle and lateral meniscus of femur.
Describe the locking of the knee
Flat surfaces of femoral condyles in contact with tibial plateaus. The femur rotates medial to lock the knee. Vastus medialis locks the knee, aided by glut max and TFL
Describe how the knees unlock
The femur must rotate laterally to unlock, this occurs due to contraction of popliteus.
Describe how a ruptured anterior cruciate ligament can occur and the clinical sign to test it
It occurs due to posterior impact. The clinical sign is called an anterior drawer sign, it shows the tibia moving forward.
Describe how a ruptured posterior cruciate ligament can occur and the clinical sign to test it
It can occur from anterior impact. The clinical sign is called the posterior drawer sign, is shows the tibia moving posterior.
What muscles are in the superficial posterior compartment and what is their function and what are they supplied by?
Gastrocnemius, soleus and plantaris. They all plantarflex the ankle and gastrocnemius flexes the knee. Supplied by posterior tibial artery and tibial nerve.
What is special about plantaris?
Like palmaris longus, is it a spare muscle with a small belly and long tendon so it can be used to do tendon repairs
What is the sural nerve formed by and why is it special
Formed by lateral cutaneous sural nerve from deep peroneal nerve and the medial cutaneous sural nerve from the tibial nerve. It can be used as a nerve graph
What does the small saphenous vein merge with and what is it accompanied by?
It merges with deep veins to form the popliteal vein. It is accompanied by the sural nerve.
What are gastrocnemius, soleus (and sometimes plantaris) collectively known as? and what is their role
Triceps Surae (meaning calf). They propel the body forward off the planted foot during walking. Elevates the body upward onto toes.
What is the common insertion for the posterior superficial muscles
The posterior surface of calcaneous via the calcaneal tendon
What are the Deep flexors of the leg? and what are they supplied by?
Flexor hallucis longus, flexor digitorum longus, tibialis posterior. Supplied by tibial nerve
What are the actions of the deep flexors of the leg?
FHL - Flexes big toe. FDL - flexes lateral 4 digits. Tibialis Posterior - plantarflexion, inversion and maintains medial longitudinal arch
Describe the Achilles reflex
Elicted by striking the Calcaneal tendon. It tests S1 ans S2 spinal segments.
What muscles are in the anterior compartment and what are they are supplied by?
Tibialis anterior, EHL, EDL. They are supplied by the anterior tibial artery and deep fibular nerve
Describe features of the deep fibular nerve
Arised between Fibularis longus and neck of fibula. Descends between tibialis anterior and EHL. Accompanied by anterior tibial artery
Describe features of the anterior tibial artery
Passes anterior to IO membrane. Descends between tibialis anterior and EHL. At the ankle is becomes dorsalis pedis
What is fibularis tertius?
It is fibres of the EDL
What are the functions of the extensors of the leg?
EHL - extension of big toe and dorsiflexion. EDL - extension of lateral four toes and dorsiflexion. Tibialis anterior - dosiflexion and inversion. FIbularis tertius - eversion and dorsiflexion.
What are the muscles in the lateral compartment of the leg? What are they supplied by?
Fibularis longus and fibularis brevis. They are supplied by the perforating branches of the anterior tibial and fibular artery and the superficial fibular nerve
What are the actions of fibularis longus and fibularis brevis
Longus - eversion and plantarflexion.
Brevis - Eversion of the foot
