Which nerve root level relates to weakness in the anterior tibialis and extensor hallicus longus and sensory loss over the medial dorsum of the foot?

Which nerve root level relates to weakness in the anterior tibialis and extensor hallicus longus and sensory loss over the medial dorsum of the foot?

• A. L3
• B. 4
• C. L5
• D. S1

Answer: (C)

Weakness in the anterior tibialis and extensor hallucis longus, along with sensory loss over the medial dorsum of the foot, indicates involvement of the L5 nerve root. The anterior tibialis muscle is responsible for dorsiflexion of the foot, and the extensor hallucis longus contributes to extending the big toe and dorsiflexion. The sensory distribution of the L5 nerve root includes the lateral aspect of the lower leg and part of the dorsum of the foot. In this case, weakness in those specific muscles suggests dysfunction at the level of the L5 nerve root, impacting its motor function, while sensory loss in that region further supports the involvement of L5, as it serves that area of the skin. Therefore, identifying L5 as the correct answer reflects an understanding of the neuroanatomy and functional deficits associated with specific nerve roots and their corresponding musculature and sensory zones.

Weakness in the anterior tibialis and extensor hallucis longus, along with sensory loss over the medial dorsum of the foot, indicates involvement of the L5 nerve root. The anterior tibialis muscle is responsible for dorsiflexion of the foot, and the extensor hallucis longus contributes to extending the big toe and dorsiflexion. The sensory distribution of the L5 nerve root includes the lateral aspect of the lower leg and part of the dorsum of the foot.

In this case, weakness in those specific muscles suggests dysfunction at the level of the L5 nerve root, impacting its motor function, while sensory loss in that region further supports the involvement of L5, as it serves that area of the skin. Therefore, identifying L5 as the correct answer reflects an understanding of the neuroanatomy and functional deficits associated with specific nerve roots and their corresponding musculature and sensory zones.