ANAT: Integrative anatomy of the lower limb

Question 1

What are the nerves of the lumbosacral plexus and which roots do they come from?

Answer 1

• Femoral nerve - L2-4
• Obturator nerve - L2-4
• Lumbosacral trunks - L4-5
• Superior gluteal nerve - L4-S1
• Inferior gluteal nerve - L5-S2
• Sciatic nerve - L4-S3:
  
  • tibial nerve
  • common peroneal nerve

Question 2

Which nerve supplies the anterior comparment of the thigh? Is it dorsal or ventral?

Answer 2

Femoral nerve (L2-4), Dorsal

Question 3

Which nerve supplies the “lateral” compartment of the thigh? Is this dorsal or ventral?

Answer 3

Gluteal nerves (L4-5, S1-3), dorsal

Question 4

Which nerve supplies the medial compartment of the thigh (responsible for adduction)? Is it ventral or dorsal

Answer 4

Obturator nerve (L2-4), ventral

Question 5

Which nerve supplies the posterior compartment of the thigh? is it dorsal or ventral?

Answer 5

Tibial nerve (L4-5, S1-3), ventral

Question 6

Which nerve supplies the posterior compartment of the leg? Ventral or dorsal?

Answer 6

Tibial nerve (L4-5, S1-3), ventral

Question 7

Which nerve supplies the anterior compartment of the leg? Ventral or dorsal?

Answer 7

Deep peroneal nerve (L4-5, S1-3), dorsal

Question 8

Which nerve supplies the lateral compartment of the leg? Ventral or dorsal?

Answer 8

Superficial peroneal nerve (L4-5, S1-3), Dorsal

Question 9

Which nerve supplies the sole of the foot? Ventral or dorsal?

Answer 9

Tibial nerve (L4-5, S1-3), ventral

Question 10

What are the 2 phases of the gait cycle?

Answer 10

Stance phase and swing phase

Question 11

What are the 5 components of stance phase?

Answer 11

• HS - heel strike
• FF - then toe comes down (foot flat)
• MS - body over grounded foot (midstance)
• HO - heel comes off ground (heel off)
• TO - toes come off ground (toe off)

Question 12

What is the leg muscles’ response at heel strike (and immediately after)?

Answer 12

Extension!

• Hamstrings act eccentrically to control hip flexion
• Quadruceps act eccentrically to control knee flexion
• Anterior tibial muscles act eccentrically to lower the forefoot in a controlling way

Question 13

When we see a limp, what is it that we actually see?

Answer 13

Not the actual muscle failure, but the body compensating for the weakness.

Question 14

Describe a hip extensor limp

Answer 14

• See them throwing weight backwards at HS
• Torso’s CoG is behind the hip
• Controls tendency to uncontrolled flexion at heel strike

Question 15

Explain a knee extensor limp

Answer 15

• We see the person throwing their weight forwards
• Maybe using their hand to press down on their thigh

Question 16

Explain an ankle extensor limp

Answer 16

• “Foot slap”
• Weakened anterior tibial uscles can’t control foot flexion
• Fore foot slaps down onto the ground after heel strike

Question 17

What produces most of the movements during stance phase?

Answer 17

Forward momentum of the body/torso

Question 18

What is the cause of a Tendelenberg gait/limp?

Answer 18

Compromise lesser gluteals, so patient throws weight over supporting hip to prevent collapse

Question 19

What muscle actions occur during swing phase?

Answer 19

1. The hip flexes
2. Knee flexes (shortens limb to allow to swing through) then extends (as hip slows down and leg catches up)
3. The ankle dorsiflexes (lift toes to swing clear of the ground)