In 2006, Estrada saw the muscular legs of a paralyzed Englishman named Robin Gibbons and was "blown away." Gibbons had come from London to Boston to row alongside the able-bodied at an annual rowing competition, using electrodes to power his legs. Estrada was watching from the crowd. So was Rob Welch, an administrator from Spaulding Rehabilitation Hospital, where most of Boston's spinal cord injuries are treated. Recalling Gibbons' strong thighs, Welch said, "You just don't see that with paraplegia. He even had hair on his legs." In addition to muscle atrophy, the poor circulation of paralyzed limbs often leads to hair loss.