What is the response for the T1 myotome pattern?

The T1 myotome is primarily responsible for the motor innervation of the intrinsic muscles of the hand, particularly those involved in finger abduction and adduction. This includes the interossei muscles, which facilitate the separation and bringing together of the fingers. When testing for T1 function, assessing the ability to abduct and adduct the fingers provides insight into the integrity of the lower trunk of the brachial plexus, specifically the T1 nerve root.

In contrast, the other options relate to different myotome patterns. Elbow flexion is predominantly controlled by the C5 and C6 myotomes, knee flexion involves the L5 and S1 myotomes, and wrist extension is associated with the C6 and C7 myotomes. Thus, finger abduction and adduction is the correct response as it is uniquely linked to T1 function.