On shelves at a Humanetics facility in Huron, Ohio, skulls stare from their eyeless sockets, shiny and silver. Around a corner, a rack is filled with squishy, peach-toned arms, legs, torsos and butts.

Maria Weston Kuhn had one lingering question about the car crash that forced her to have emergency surgery during a vacation in Ireland: Why did she and her mother sustain serious injuries while her ...