After running, descending, long miles on a steep trail I'm finding that the worst pain/soreness in my legs are due to loose earth like gravel. Its hard to tell which muscles are hurting and Ive only experienced the pain two times, and ran this type of long run on steep trails only twice. Im a flatlander... I feel it the most after the run while walking on loose gravel, but also while running I feel it enough to change the way I descend down a trail which slows me down.
More specifically, any side-wards motion due to slips or bumping against roots. This has only happened twice but the pain was definitely below the knee and maybe mostly on the front outer side of leg.
Instead of trying to say what muscles are hurting me can someone tell me what muscles are responsible for stabilizing your feet and some suggestion for strengthen them in general or for running.
What muscles are these and how do you strengthen them?