Intermediate Lumbricals Quiz

Q1. Which lumbrical is typically unipennate?

• Second lumbrical
• Third lumbrical
• Fourth lumbrical
• First lumbrical

Q2. How do the second through fourth lumbricals usually arise?

• From adjacent sides of two flexor digitorum longus tendons
• From the metatarsal shafts only
• From extensor digitorum longus
• From the calcaneal tuberosity only

Q3. On which side of each associated toe does a lumbrical tendon pass before joining the extensor expansion?

• Medial side
• Through the plantar plate
• Directly through the proximal phalanx
• Lateral side

Q4. Which lumbricals share the same general innervation pattern as the hand, with the most medial supplied differently from the others?

• First three by sural nerve and fourth by tibial nerve
• First by medial plantar nerve, lateral three by lateral plantar nerve
• All four by deep fibular nerve
• All four by medial plantar nerve

Q5. Why can the lumbricals extend the interphalangeal joints even though they originate from flexor tendons?

• They attach directly to the distal tibia
• They insert into the extensor expansions
• They cross dorsal to the ankle
• They insert on the calcaneus

Q6. What is the relationship of the lumbricals to the flexor digitorum longus tendons?

• They arise from the flexor digitorum longus tendons
• They have no relationship to digital flexor tendons
• They form the flexor digitorum longus tendon
• They lie only dorsal to the extensor tendons

Q7. Which arterial network contributes to the blood supply of the plantar lumbricals?

• Plantar arterial branches
• Descending genicular artery only
• Anterior tibial recurrent artery only
• Superior gluteal artery only

Q8. How do lumbricals contribute to controlled toe posture during stance?

• They are the primary plantarflexors of the ankle
• They help balance flexor and extensor forces across the toe joints
• They abduct all toes from the second digit
• They lock the ankle mortise directly

Q9. Which structure lies in the same second plantar layer and modifies the pull of flexor digitorum longus?

• Extensor digitorum brevis
• Abductor hallucis
• Quadratus plantae
• Adductor hallucis

Q10. Why are the lumbricals described as unusual intrinsic muscles?

• They originate from the femur
• They contain no skeletal muscle fibers
• They originate from the tendons of another muscle
• They have no nerve supply