Hi...I'm a new rider who just passed his road test (thank you PRS!)..and I'm noticing that after every ride, the muscle/tendon along the bottom of my thumbs hurt. I don't actually have a bike yet, and the muscles/tendons have been hurting since the beginning of June, when I did my PRS training...has anyone had any experience with this? Or perhaps know what I'm doing wrong? I would appreciate any tips. Thanks!