This was probably just me, but I found that the peddle would roll back as I was going up hill and encountered a large rock or root. I would try to put the power down and the foot would roll off the back of the peddle and the shins would get beet up. I more than likely had my foot positioned too far back on the peddle contributing to my issue!. So to help try putting your foot a bit more forward on the peddle if you experience any of that. Good luck and happy riding!