Question

Supraspinatus

a) extends shoulder; adducts and rotates arm
b) extends shoulder; laterally rotates arm
c) abducts arm
d) pronates forearm

Answer 1

The supraspinatus muscle functions to abduct the arm. It is part of the rotator cuff, which encompasses four muscles around the shoulder joint. The relevant option indicating that the supraspinatus abducts the arm is option (c).

Step-by-step explanation:

The question is asking about the function of the supraspinatus muscle, specifically its action related to the movement of the arm. Looking at the options provided in the question:

1. Option (a) is not correct as it includes adduction, which is not a function of the supraspinatus.
2. Option (b) mentions extending the shoulder and laterally rotating the arm; again this is not a motion performed by the supraspinatus.
3. Option (c) says the supraspinatus abducts arm, which is correct. The supraspinatus is one of the muscles that form the rotator cuff, and is responsible for the initial phase of arm abduction.
4. Option (d) refers to pronating the forearm, which is unrelated to the supraspinatus as it involves muscles of the forearm.

Therefore, the correct answer to the question is:

c) abducts arm