Which muscle is primarily responsible for external rotation in addition to infraspinatus?

Which muscle is primarily responsible for external rotation in addition to infraspinatus?

• A. Supraspinatus
• B. Teres minor
• C. Subscapularis
• D. Deltoid

Answer: (B)

The teres minor muscle plays a significant role in external rotation of the humerus, particularly in conjunction with the infraspinatus muscle. Both of these muscles are part of the rotator cuff group and are critical for facilitating movements of the shoulder joint. The teres minor originates from the lateral border of the scapula and inserts on the greater tubercle of the humerus. Its orientation allows it to effectively assist in externally rotating the arm at the shoulder. In addition to external rotation, the teres minor also contributes to stabilization of the shoulder joint during movement. Understanding the function of the teres minor is important for recognizing its contribution to shoulder mechanics. Complementing the infraspinatus, which is also primarily involved in external rotation, the teres minor enhances the ability to rotate the arm away from the body, an essential movement in various activities ranging from sports to daily tasks.

The teres minor muscle plays a significant role in external rotation of the humerus, particularly in conjunction with the infraspinatus muscle. Both of these muscles are part of the rotator cuff group and are critical for facilitating movements of the shoulder joint.

The teres minor originates from the lateral border of the scapula and inserts on the greater tubercle of the humerus. Its orientation allows it to effectively assist in externally rotating the arm at the shoulder. In addition to external rotation, the teres minor also contributes to stabilization of the shoulder joint during movement.

Understanding the function of the teres minor is important for recognizing its contribution to shoulder mechanics. Complementing the infraspinatus, which is also primarily involved in external rotation, the teres minor enhances the ability to rotate the arm away from the body, an essential movement in various activities ranging from sports to daily tasks.