Lecture 12 - Muscles of the Leg

Question 1

Superficial posterior compartment of the legs? Common function?

Answer 1

FLEXOR muscles
1. gastronemius
2. soleus
3. plantaris (tendon)

Question 2

gastrocnemius
function and innervation

Answer 2

Fun: (2)
Plantar flex. of foot (ankle J.)
Flex. of leg (knee J.)

N: Tibial

Question 3

soleus
function and innervation

Answer 3

Fun: (1) Plantar flexion of the foot (ankle J.)

N: Tibial

Question 4

plantaris
function and innervation

Answer 4

Fun: (2) (weak)
Plantar flex. of foot (ankle J.)
Flex. of leg (Knee J.)

N: Tibial

Question 5

Deep posterior compart of the leg muscle? What is their common function? Common innervation?

Answer 5

Deep FLEXOR muscles
1. flexor hallucis longus
2. flexor digitorum longus
3. tibialis posterior
4. popliteus

N: Tibial Nerve

Question 6

flexor hallucis longus
function and innervation

Answer 6

Fun: (3)
Flex. of big toe @ MTP & IP joints.
Plantar flexion of foot @ the ankle J.
Inversion of foot @ the subtalar J.

N: Tibial

Question 7

flexor digitorum longus
function and innervation

Answer 7

Fun: (3)
1. Flex. of toes #2-5 @ MTP and PIP & DIP joints.
2. Plantar flexion of foot @ ankle J.
3. Inversion of foot @ subtalar J.

N: Tibial

Question 8

tibialis posterior
function and innervation

Answer 8

Fun: (2)
1. Plantar Flex. of foot @ ankle J.
2. Inversion of foot @ subtalar J.

N: tibial

Question 9

popliteus
function and innervation

Answer 9

popliteus is the key to unlock the knee!

Function
1. Flex. of leg @ the knee J.
2. Med. Rot. of leg @ knee J. (to unlock the extended knee)

N: Tibial

Question 10

Arrangement of the Anatomical Structures Passing Behind the Medial Malleolus?

Answer 10

Tom Dick And Very Nervous Harry

Tibialis posterior

flexor digitorum longus

artery, vein

nerve

flexor hallusic longus

Question 11

Popliteal Fossa

Answer 11

Superomedial: semimembranosus and semitendinosus muscles

Lateral: biceps femoris muscle

Inferior: gastrocnemius muscle

Floor: knee joint capsule, distal femur, proximal tibia, popliteus muscle

Roof: popliteal fascia

Question 12

Anterior Compartment of the leg. What is their common function? What are these muscles innervated by?

Answer 12

EXTENSOR muscles

1. tibialis anterior
2. extensor hallucis longus
3. extensor digitorum longus
4. Fibularis (peroneus) tertius

N: deep peroneal (fibular) N.

Question 13

tibialias anterior
function and innervation

Answer 13

Fun: (2)
Dorsiflexion of foot @ ankle J. (prime mover of DF)
Inversion of foot @ subtalar J.

N: Deep Fibular (peroneal)

Question 14

extensor hallucis longus
function and innervation

Answer 14

Function:
1. Ext. of big toe @ MTP and IP joints
2. Dorsiflexion of foot @ ankle J.
3. Inversion of foot @ subtalar J.

N: Deep Fibular (peroneal)

Question 15

extensor digitorum longus
function and innervation

Answer 15

Function
1. Ext. of toes # 2-5 @ MTP and IP (PIP AND DIP) joints
2. Dorsiflexion of foot @ ankle J.
3. Eversion of foot @ subtalar J.

N: Deep Fibular (peroneal)

Question 16

Fibularis (peroneus) tertius
function and innervation

Answer 16

Function
1. Dorsiflexion of foot @ ankle J.
2. Eversion of foot @ subtalar J.

N: Deep Fibular (peroneal)

Question 17

lateral compart of the leg muscles. What is this group innervated by?

Answer 17

1.Fibularis (Peroneus) longus
2.Fibularis (Peroneus) brevis

N: superficial peroneal (fibular) N.

Question 18

Fibularis (Peroneus) longus
function and innervation

Answer 18

Fun: (2)
1. Eversion of foot @ subtalar J.
2. Plantar flexion of foot @ ankle J.

N: Superficial Fibular (peroneal)

Question 19

Fibularis (Peroneus) brevis
function and innervation

Answer 19

Fun: (2)
1. Eversion of foot @ subtalar J.
2. Plantar flexion of foot @ ankle J.

N: Superficial Fibular (peroneal)

Question 20

what is compartment syndrome?

Answer 20

develops when swelling or bleeding occurs within a compartment. Because the fascia does not stretch, this can cause increased pressure on the capillaries, nerves, and muscles in the compartment.

If pressure in the compartment goes up - like overuse of the muscle
It can compress the nerve

What can we expect: loss of extension (dorsiflexion) (anterior muscles)

The patient is given a splint

Question 21

what is the result of compartment syndrome?

Answer 21

Drop foot
- due to compression fo the nerve, the foot cannot do dorsiflexion

Question 22

what two muscles together are known as the Triceps Surae

Answer 22

gastrocnemius and soleus

Question 23

what role does the gastrocnemius and soleus have in venous blood return?

Answer 23

The gastro and soleus are big muscles - that compress the veins and help return of blood to the heart

Question 24

what is the DTR of S1?

Answer 24

calcaneal tendon

Question 25

what can be found on the posterior side of the knee?

Answer 25

the fabella