There are about 700 muscles in the human body, often subject to injury. Although almost any muscle can be strained or "pulled" if it's overexerted, certain muscles are more prone to injury. These include muscles in the lower back, hip, legs, neck and shoulder. If you think you may have a pulled shoulder muscle, there are certain signs and symptoms that can confirm this without the obvious step of seeing a doctor.
Locate the exact area of the pain. Is it in your muscle, or is it a shooting or traveling pain that might be centered in another nearby area such as your back or arm? Sometimes pain can be deceptive, initially focusing itself in one area before moving or spreading.
Assess whether you've suffered an injury that could have caused a pulled shoulder muscle. Did you somehow overload the muscle or do something else that might have strained it? Shoulder muscle pulls don't occur spontaneously. They're caused by a specific action or combination of actions that overexert the muscle.
Examine your shoulder or have someone else examine it for you to look for symptoms of a pulled muscle. These include tenderness and swelling. There may even be some bruising if the injury is severe and caused internal bleeding in the area of the muscle pull.
Move your arm to see if there's any impairment in your range of motion. A pulled shoulder muscle may limit your movement due to pain and inflammation.