The infraspinatus muscle is located in the shoulder blade region, specifically on the posterior (back) surface of the scapula bone. Pain from the infraspinatus muscle may be felt in the shoulder, upper back, or down the arm, depending on the severity and location of the injury or strain. Common symptoms of infraspinatus pain include limited range of motion in the shoulder, difficulty lifting or moving the arm, and pain that worsens with certain movements or activities. If you are experiencing persistent or severe pain, it is recommended that you consult with a healthcare professional for an accurate diagnosis and an appropriate treatment plan.