**Question:** Most common muscle affected in rotator cuff group is -

A. Supraspinatus
B. Infraspinatus
C. Teres minor
D. Subscapularis

**Core Concept:** Rotator cuff is a group of four muscles that surround and stabilize the humerus head in the glenohumeral joint. Their primary functions include lifting the arm and providing stability to the joint.

**Why the Correct Answer is Right:** The supraspinatus is the most commonly affected muscle in the rotator cuff group due to its close proximity to the glenohumeral joint and its involvement in overhead activities. It helps in upward rotation of the arm and is susceptible to strain, rupture, or impingement.

**Why Each Wrong Option is Incorrect:**

A. Infraspinatus: This muscle helps in downward rotation of the arm and is less commonly affected than supraspinatus.
B. Teres minor: This muscle is a smaller muscle that assists in external rotation of the humerus. Although it can be affected, it is less commonly involved compared to supraspinatus.
C. Subscapularis: This muscle plays a role in internal rotation of the humerus and is less commonly affected than supraspinatus.

**Clinical Pearl:** The rotator cuff muscles are essential for daily activities and sports involving overhead movements. Proper warm-up, strengthening, and stretching exercises can help prevent rotator cuff injuries.

**Correct Answer:** D. Subscapularis