I have cycled for most of the past three decades, and my shins have suffered for it. Aftet stopping at a red light, I often need to put the pedals back into my power stoke position to start. Often this leads the pedal to flip to the other side and mash into my shin. Over the years I've has blood shins constantly. I stopped using pedals with spikes/screws because they dug into my shins really bad and caused profuse bleeding.

Be careful with your pedals. Get pedals that will not damage your shins, or wear pants to protect them.