MMT Nerve Innervation and Muscle Function 3

Question 1

The thenar muscles tested during thumb opposition MMT are primarily innervated by which nerve?

Accepted Answer

Median nerve

Answer

The thenar muscles (abductor pollicis brevis, opponens pollicis) are innervated by the recurrent branch of the median nerve (C8-T1); carpal tunnel syndrome often weakens these muscles.

Question 2

Which nerve root is primarily responsible for shoulder external rotation, tested via the infraspinatus in MMT?

Accepted Answer

C5

Answer

Shoulder external rotation (infraspinatus and teres minor) is primarily innervated at C5 via the suprascapular and axillary nerves respectively.

Question 3

The rhomboid muscles, tested by scapular retraction in MMT, are innervated by which nerve?

Accepted Answer

Dorsal scapular nerve

Answer

The rhomboids are innervated by the dorsal scapular nerve (C4-C5) and tested via scapular retraction/adduction in MMT.

Question 4

In MMT, which muscle's grade most directly reflects C7 nerve root function?

Accepted Answer

Triceps brachii

Answer

The triceps brachii is primarily innervated at C7 via the radial nerve, making elbow extension the key MMT test for C7 nerve root integrity.

Question 5

Weakness of foot eversion during MMT implicates which nerve?

Accepted Answer

Superficial peroneal nerve

Answer

The peroneus longus and brevis (foot evertors) are innervated by the superficial peroneal nerve (L5-S1), so eversion weakness implicates this nerve.

(MMT) Manual Muscle Testing Practice Test

(MMT) Manual Muscle Testing Practice Test

MMT Nerve Innervation and Muscle Function 3