leg

Question 1

popliteal fossa:
1. what is the popliteal fossa?

2. what is it bounded by?
3. through which structure does the adductor canal open into the popliteal fossa?

Answer 1

1. diamond shaped region behind the knee joint
2. Bounded by biceps femoris, semimembranosus and tendon of semitendinosus and lateral and medial heads of the gastrocnemius
3. The adductor canal opens to the popliteal fossa through adductor
   hiatus

Question 2

popliteal fossa:

1. what 7 structures does the popliteal fossa contain?
2. in which 2 injuries is the popliteal artery at risk?

Answer 2

1. Contains
   - Popliteal artery and vein, with their branches and tributaries
   (artery slightly medial to Vein)
   - Tibial nerve
   - Common fibular nerve
   - Posterior cutaneous nerve of the thigh
   - Terminal part of small saphenous vein
   - Lymph nodes
   - Fat
2. the popliteal artery is at risk in knee dislocation and supracondylar fracture of the femur

Question 3

locking/unlocking of the Knee: when standing, what is the knee is ‘locked’ into position

1. why is it in this locked position?
2. in what action does locking occur?
3. what makes the knee locked? (ligaments)
4. describe the femoral condyles during this locked position
5. what muscles lock the knee?

Answer 3

1. it is in this locked position to reduce the amount of muscle work needed to maintain the standing position
2. Locking occurs in the last 30 degrees of extension
3. ligaments are tightened
4. Flat surface of the femoral condyles are in contact with the tibia plateaus = joint surfaces become larger
5. Vastus medialis locks the knee, aided by Gluteus maximus, tensor fascia lata

Question 4

popliteus:

1. what position must the femur be in, for flexion of the knee?
2. what does the popliteus muscle do?
3. what is the origin of the popliteus muscle?
4. what is the insertion of the popliteus muscle?

Answer 4

1. During flexion of the knee, femur must initially be rotated laterally
2. Popliteus laterally rotates the femur and un-locks the knee (when standing, i.e. in closed kinetic chain)
3. origin: Lateral surface of lateral condyle of femur and lateral meniscus
4. insertion: posterior surface of tibia, superior to soleal line

Question 5

compartments of the leg: posterior compartment

1. what is the posterior compartment of the leg divided into?
2. what muscles does the superficial flexor compartment contain?
3. what are the 2 functions of the posterior compartment?
4. what is the posterior compartment supplied by?

Answer 5

1. the posterior compartment is divided into superficial and deep flexor compartments
2. Gastrocnemius, soleus and plantaris
3. primarily flexes the ankle but gastrocnemius also flexes the knee
4. it is supplied by the tibial nerve and posterior tibial artery

Question 6

superficial flexors:

1. what are gastrocnemius and soleus (sometimes plantaris) collectively called?
2. what 2 functions does this do?

Answer 6

1. gastrocnemius and soleus (sometimes plantaris) are collectively called triceps surae
2. the triceps surae:
   - pushes the body forward off the planted foot during walking
   - elevates the body upward onto the toes when standing

Question 7

calcaneal tendon:

1. where does the calcaneal tendon insert?
2. where does bursa lie?
3. what happens in a calcaneal tendon rupture?

Answer 7

1. inserts into the middle of the back of calcaneus bone
2. there is a bursa between the deep surface and the bone
3. there is no power of plantar flexion against resistance, which can be tested with the Thompson’s test (calf squeeze test)

Question 8

deep flexor compartment:

1. what muscles make up the deep flexor compartment?
2. what are they also known as?
3. what is the deep flexor compartment innervated by?
4. what is the deep flexor compartment supplied by arteriorly?

Answer 8

1. Flexor hallucis longus, flexor digitorum longus
   and tibialis posterior
2. with the exception of tibialis posterior, deep flexors are extrinsic flexors of the toes
3. it is supplied by the tibialis nerve
4. the posterior tibial artery, which is accompanied by the tibial nerve, descends deep to the soleus muscle towards the medial malleolus

Question 9

flexors of the ankle:

1. what are the 4 flexor muscle of the ankle?
2. what are the origins of each muscle?
3. what are the insertions of each muscle?
4. what are they innervated by?
5. what is the primary function of the tibialis posterior?
6. what is the soleus mostly responsible for?

Answer 9

Question 10

extrinsic flexors of the toes:

1. what are the 2 extrinsic flexors of the toes?
2. what are the origins of these muscles?
3. what are the insertions of these muscles?
4. what are they supplied by?
5. what is the function of the flexor hallucis longus?

Answer 10

Question 11

1. how is the ankle reflex (achilles refelx) tested?
2. which nerve roots does it test?

Answer 11

1. Elicited by striking the calcaneal tendon briskly
2. Tests the S1 and S2 nerve roots

Question 12

anterior compartment:

1. what muscles are within the anterior compartment
2. what do they all act on?
3. what muscle is part of the EDF (extensor digitorum longus)?
4. what artery are they supplied by?

Answer 12

1. Tibialis anterior (TA), Extensor hallucis longus (EHL) and Extensor digitorum longus (EDL)
2. With the exception of tibialis anterior, they all act on the toes
3. Fibularis [peroneus] tertius is part of extensor digitorum longus
4. supplied by the anterior tibial artery

Question 13

deep fibular nerve:

1. where does the deep fibular nerve arise between?
2. where does it descend?
3. what is it accompanied by?

Answer 13

1. deep fibular nerve arises between fibularis longus muscle and neck of fibula
2. it descends between tibialis anterior and extensor hallucis longus on the interosseal membrane
3. it is accompanied by anterior tibial vessels

Question 14

anterior tibial artery;

1. what does the anterior tibial artery descend on?
2. what is it accompanied by?
3. what does it supply?
4. what does it become at the ankle?

Answer 14

1. it descend on the anterior surface of the interosseal membrane
2. it is accompanied by the deep fibular (peroneal) nerve
3. it supplies the muscles in the anterior compartment of the leg (dorsiflexors)
4. at the ankle, it becomes the dorsalis pedis artery

Question 15

1. what is the one extensor muscle of the ankle?
2. what is its origin and insertion?
3. what is the extension of the ankle also referred to as?
4. what is it supplied by?
5. what 2 action does it do to the foot?

Answer 15

1. tibialis anterior
2. origin = lateral condyle and superior-lateral surface of tibia and interosseous membrane

insertion = medial cuneiform and base of 1st metatarsal

3. dorsiflexion = extension of the ankle
4. Tibialis anterior, as with all muscles in the anterior compartment of the leg is supplied by the deep fibular [peroneal] nerve
5. tibialis anterior inverts the foot + supports the medial longitudinal arch of the foot

Question 16

extrinsic extensors of the toes:

1. what are the three extrinsic extensors of the toes?
2. what are their origins and insertions?
3. what are they supplied by?

Answer 16

Question 17

lateral compartment:

1. what are the 2 muscles within the lateral compartment of the leg?
2. what arteries supply them primarily?
3. where does the superficial fibular nerve arise from?
4. where does the superficial fibular nerve descend in?
5. when does it become superficial?

Answer 17

1. fibularis longus and fibularis brevis
2. it is supplied primarily by the branches of anterior tibial artery
3. Superficial fibular nerve arises between fibularis longus and neck of fibula
4. Descends in lateral compartment of the leg
5. At distal 1/3 of leg, becomes superficial

Question 18

inversion and eversion:

1. what muscle evert and flex the foot?
2. what do the tendons of these muscle pass behind?
3. what tendon passes across the sole of the foot?

Answer 18

1. The fibular muscles evert and plantar flex the foot
2. Tendons of fibular muscles pass behind the lateral malleolus
3. Tendon of the fibularis longus passes across the sole (lateral longitudinal arch support)

Question 19

inversion and eversion:

1. what two muscles are involved in inversion of the foot?
2. what are the muscles involved in eversion?
3. what what are the peroneus muscles supplied by?
4. what 2 actions does the fibularis longus allow?
5. what does the fibularis brevis do?

Answer 19

Question 20

sural nerve:

1. what function is the sural nerve?
2. what nerve is the lateral cutaneous sural nerve branch from?
3. what nerve is the medial cutaneous sural branch from?
4. what may the sural nerve used for?

Answer 20

1. the sural nerve is a sensory nerve
2. Lateral cutaneous sural branch from the common fibular nerve
3. Medial cutaneous sural branch from the tibial nerve
4. may be used as a nerve graft

Question 21

short saphenous vein:

1. what does the short-saphenous vein penetrate?
2. what does it merge with to form?

Answer 21

1. Small (short) saphenous vein penetrates the deep fascia of the leg between the heads of the gastrocnemius muscle.
2. Merges with deep veins to form the popliteal vein.