What Causes Sharp Pain Between Shoulder Blades?

Hi Doctor. I was shoveling heavy sleet from my driveway about an hour ago, and shortly thereafter, I started experiencing a sharp pain between my shoulder blades. It felt almost like the way my elbow feels when I hit my funny bone. The pain was sharp at first, then became more lingering. Once I started moving around again, it starting gradually worsening, and about a half hour ago, it felt really sharp any time I would move. Now, fifteen minutes later, the pain is still lingering, and I ve started moving around without it worsening. It s settled into being just a sore sensation when I move my shoulders. I ve never had muscle spasms or pinched a nerve, which is what my brother seems to think it is, but I want to be more sure before I start relaxing about it.