Advanced Flexor Digitorum Longus Quiz

Q1. Why can a tibial nerve lesion proximal to the ankle weaken flexor digitorum longus?

• Its motor supply arises from the femoral nerve
• Its motor supply travels in the tibial nerve
• Its motor supply is entirely within the medial plantar nerve
• Its motor supply travels only in the deep fibular nerve

Q2. Why does flexor digitorum longus flex the distal interphalangeal joints while flexor digitorum brevis does not?

• Its tendons continue to the distal phalanges
• It does not cross any toe joint
• It inserts on the metatarsal heads
• Its tendons end on the proximal phalanges

Q3. Why is the relationship between flexor digitorum longus and quadratus plantae mechanically important?

• Quadratus plantae separates the tendon from all digital branches
• Quadratus plantae extends the toes against the long flexor
• Quadratus plantae converts the tendon into an ankle dorsiflexor
• Quadratus plantae helps correct the oblique pull of the long flexor tendon

Q4. Why can pathology within the tarsal tunnel affect the flexor digitorum longus tendon region?

• The tendon lies within the femoral sheath
• The tendon crosses the greater sciatic foramen
• The tendon passes through the extensor retinaculum on the dorsum
• The tendon passes through the confined region beneath the flexor retinaculum

Q5. How does the insertion of flexor digitorum longus differ from that of flexor digitorum brevis?

• Longus inserts on middle phalanges while brevis reaches distal phalanges
• Both insert only on proximal phalanges
• Both insert on the calcaneus
• Longus reaches distal phalanges while brevis inserts on middle phalanges

Q6. Why can flexor digitorum longus contribute to foot stability during stance?

• It extends the toes away from the ground
• Its tendons stabilize the toes and support the longitudinal arches
• It acts only when the foot is non-weight-bearing
• It locks the patella against the femur

Q7. Why is the knot of Henry clinically relevant?

• It is a crossing point between the long flexor tendons of the hallux and lateral toes
• It is the crossing of the tibial and common fibular nerves
• It is the junction of the plantar fascia and patellar ligament
• It is the insertion of the Achilles tendon

Q8. Which feature helps distinguish the flexor digitorum longus tendon from flexor hallucis longus behind the medial malleolus?

• It is the most posterior tendon in the tunnel
• It lies anterior to tibialis posterior
• It passes outside the flexor retinaculum
• Flexor digitorum longus lies anterior to the neurovascular bundle and flexor hallucis longus

Q9. Why may weakness of flexor digitorum longus reduce effective push-off?

• It abolishes hip extension
• It prevents quadriceps contraction
• It directly paralyzes the intrinsic toe extensors
• It reduces toe stabilization and part of the plantarflexion contribution

Q10. Which statement best integrates the anatomy of flexor digitorum longus?

• It is a tibial-nerve-supplied deep posterior leg muscle that flexes toes two through five and assists plantarflexion
• It is a femoral-nerve-supplied thigh muscle that extends the knee
• It is a deep-fibular-nerve-supplied anterior leg muscle that extends the lateral four toes
• It is a superficial-fibular-nerve-supplied lateral leg muscle that only everts the foot