Kevan Chandler, far right, poses with friends Tom Troyer, left, and Luke Thompson, center, on a backpacking trip through Europe in 2016. Kevan has a rare neuromuscular disease called spinal muscular atrophy where the muscles no longer respond to nerve signals which causes his muscles to atrophy. The backpacking adventure is documented in the new children's book "We Carry Kevan." Photo courtesy of Kevan Chandler, taken by wife Katie Chandler.