Muscle knots in the Trapezius are most often found right in the meaty ridge of your upper shoulder, where the trapezius meets your neck, and along the shoulder blades. These muscle knots become irritated, the pain typically travels up your neck to the base of your skull and can even wrap around the side of your head, causing a tension headache or a headache behind your eye. Knots lower down in your trap, near your shoulder blade, typically keep the pain localized, making the area feel stiff and achy, right between your shoulder blades.