MMT Nerve Innervation and Muscle Function 2

Question 1

Weakness of the tibialis anterior during MMT dorsiflexion testing most directly implicates which nerve root?

Accepted Answer

L4

Answer

The tibialis anterior is innervated by the deep peroneal nerve at L4-L5, with L4 being the dominant root level identified during MMT.

Question 2

The serratus anterior, tested by scapular protraction in MMT, is innervated by which nerve?

Accepted Answer

Long thoracic nerve

Answer

The long thoracic nerve (C5-C7) innervates the serratus anterior; injury causes medial scapular winging observed during MMT.

Question 3

During MMT, weakness of elbow extension most directly implicates which nerve at which root level?

Accepted Answer

Radial nerve C7-C8

Answer

Elbow extension (triceps brachii) is innervated by the radial nerve at C7-C8, with C7 being the key root level tested.

Question 4

The gluteus maximus, the primary muscle for hip extension MMT, is innervated by which nerve?

Accepted Answer

Inferior gluteal nerve

Answer

The gluteus maximus is innervated by the inferior gluteal nerve (L5-S2), making it the nerve tested during hip extension MMT.

Question 5

In MMT, weakness of extensor hallucis longus (great toe extension) is a classic indicator of which nerve root dysfunction?

Accepted Answer

L5

Answer

The extensor hallucis longus is innervated by the deep peroneal nerve at L5, making great toe extension weakness a hallmark L5 nerve root sign.

(MMT) Manual Muscle Testing Practice Test