What nerve root is tested by extensor hallucis longus?

Prepare for the Neuromusculoskeletal II Lecture Exam with detailed study guides, flashcards, and multiple choice questions. Unlock comprehensive insights and enhance your knowledge for success.

Multiple Choice

What nerve root is tested by extensor hallucis longus?

The main idea is localizing a nerve root by a specific muscle action. Extensor hallucis longus extends the big toe and is innervated mainly by the deep peroneal nerve from the L5 root. So testing the ability to extend the big toe (and resist toe extension while dorsiflexing the foot) specifically gauges the L5 myotome. If L5 is affected, you’ll see weakness in big toe extension, which is a classic sign of L5 radiculopathy. In contrast, other roots don’t control this action as directly: L4 is more tied to general dorsiflexion via tibialis anterior, L3 relates more to hip/knee functions, and S1 to plantarflexion. Therefore, L5 best explains the extensor hallucis longus function.

The main idea is localizing a nerve root by a specific muscle action. Extensor hallucis longus extends the big toe and is innervated mainly by the deep peroneal nerve from the L5 root. So testing the ability to extend the big toe (and resist toe extension while dorsiflexing the foot) specifically gauges the L5 myotome. If L5 is affected, you’ll see weakness in big toe extension, which is a classic sign of L5 radiculopathy. In contrast, other roots don’t control this action as directly: L4 is more tied to general dorsiflexion via tibialis anterior, L3 relates more to hip/knee functions, and S1 to plantarflexion. Therefore, L5 best explains the extensor hallucis longus function.

More practice questions