Unfortunately predicting RSD spread is tough. Everyone is different & every new injury is different. My RSD started in my right arm from an unknown injury. While detoxing from some of my pain meds, I passed out in the shower & apparently hit my foot on the drain in the tub/shower. That caused the RSD to spread to my right foot. However, I have had several bad falls since that & it didnt cause spread. RSD has also spread into my back, stomach, & heart and I don't know why. My best advice is to keep your stress as low as possible so your nervous system isnt in high gear. I wish you luck!! As soon as you can, get your injured area moving as much as possible. I wish I could help you more!!!