Which of the Following Statements About the Shoulder Joint Is

Question

Which of the following statements about the shoulder joint is true?
A) Muscles whose action lines cross the anterior aspect of the shoulder joint are extensors.
B) Muscles whose action lines cross the anterior aspect of the shoulder joint may produce lateral extension.
C) Muscles whose action lines cross the inferior aspect of the shoulder joint may produce extension.
D) Muscles whose action lines cross the posterior aspect of the shoulder joint may produce extension.
E) Muscles whose action lines across the superior aspect of the shoulder joint are adductors.

Accepted Answer

Muscles that cross the posterior aspect of the shoulder joint may produce extension. This includes muscles such as the latissimus dorsi and teres major. None of the other statements are true - muscles crossing the anterior aspect may produce flexion or abduction, muscles crossing inferiorly may produce adduction or internal rotation, and muscles crossing superiorly may produce abduction or elevation.