Which statement regarding a muscle is FALSE if it is innervated by the lower scapular nerve?

The statement regarding a muscle innervated by the lower scapular nerve being responsible for abducting the humerus is incorrect because the muscles innervated by this nerve primarily include the teres major and parts of the subscapularis. The teres major assists in actions such as extending and internally rotating the humerus, while the subscapularis is involved in internal rotation and adduction. Therefore, these muscles do not facilitate abduction of the humerus, which is primarily carried out by the deltoid and supraspinatus muscles.

On the other hand, the flexion and extension of the humerus relate to the roles of muscles such as the pectoralis major and the teres major, with the latter having a role in extension. Consequently, the lower scapular nerve innervates muscles that contribute to flexion and extension, making the assertion that it participates in the abduction of the humerus false. This distinction highlights the specific functions of muscle innervation and reinforces the understanding of muscle actions related to the shoulder complex.