Hi. I've been running for ~30 years, but just recently got into trail racing. Lately I've done two very technical courses. The last one was long for me about 8. It was very rooty (took my first fall) and I was looking down for close to 2 hours. My mid-back (rhomboids? Either side of spine) was killing me after an hour. How do you get used to running looking down? Just get more practice? It really hurt although after I finished the pain went away.