I've heard of how walking barefoot in grass can strengthen feet and lower legs. Does anyone have experience with this. I have a history of niggling lower-leg injuries, so last night after my run I walked for 5 minutes barefoot in the grass. Is this something I should do a few times per week? Maybe increase to 10-15 minutes? I'm running anywhere from 70-90mpw right now, but hope to increase it to 100+ by end of April/early May. Thanks.