I've been practicing rear wheel hops for the past couple of days, and besides painful blisters, my forearm, lower part of my bicep, and the area next to my shoulder blade on my back have begun to ache. I was just wondering if this means I'm doing something wrong and hurting myself or if its just something you get used to (sore because i usually dont use those muscles). I'm coming off an inflamed rotator cuff injury from tennis (which led to 3 months off riding) so i'm trying to play it safe for a while, any help or advice would be great. Cheers.