While running, most of the aches and pains you experience tend to crop up somewhere below the waist. However, running engages your upper limbs in a rhythmic and repetitive way even if it doesn't pound them the way it does your knees and feet. Your arms swings back and forth almost 1,000 times per mile, so pain below the shoulder blades is not unusual in runners, with specific form problems and muscle weaknesses being the usual culprits.
When you become tired, either as a result of going farther than you're used to or holding an unusually fast pace for a typical distance, your arms tend to fatigue and you naturally draw your shoulders upward an inward, usually without knowing it since you're distracted by the more obvious burning in your legs and lungs. Dr. Dana Williamson notes that consciously relaxing your shoulders when you're running can keep tension out the muscles attached to your shoulder bladed, including the trapezius and levator scapulae.
Strength, Form and Flexibility
Dr. Williamson says that exercising and stretching some of the muscles you pay less attention to as a runner can help ease pain in the upper back. For example, run tall and consciously expand the rib cage as you move along to bring the shoulder blades apart and increase the tone of the muscles between them. You can also try boosting the range of motion in the area before or after running by gently stretching your neck forward, backward and side-to-side and also doing neck rotations. If you bring your shoulders upward and backward and squeeze your shoulder blades together, you should feel a difference in tightness right away.
What you do when you're not running can greatly affect how your body feels when you're working out. This is particularly true of the upper back, since so many people spend a major part of their work day sitting or driving. If you use a computer, try to maintain an ergonomic position -- don't slouch, and keep the mouse in a comfortable position rather than right in front of you, too far to one side, too high or too low. When driving, keep your arms loose and as low to the sides as you can. Finally, try not to sleep on your side too much.
As the name implies, a winged scapula is a visible protrusion of the shoulder blade, usually as a result of weakness in the serratus anterior muscles but sometimes as a result of injury to the nerve controlling them. Runners experiencing shoulder-blade pain in the presence of a winged scapula are more apt to ave suffered an injury, such as a blow to the shoulder. If you have a winged scapula but no pain, still strengthen the muscles using wall push-ups or a punching bag to reduce the chance of injury and improve your running form and overall posture.