DAVENPORT, Iowa — A week before Daniel Griffin planned to cycle across Iowa, he faced a challenge most bikers never consider: How would he stay strapped into the left pedal? A brain tumor and six surgeries had left the 16-year-old with a drop foot incapable of moving up and down. His toes wouldn’t wiggle either. Weeks before the late-July trek, his appendix burst. He had hundreds of miles of ...