Brannock Brannock, a Boston Marathon bombing victim, slides to the edge of her wheelchair. She looks down at a pair of carefully selected gray New Balance sneakers. And stands. Her thigh slides deeper into a soft plastic socket as she shifts her weight from her right leg to her new prosthetic leg. The bone where her left leg was amputated sends a sharp, shooting pain, and she starts to cry. Not because it hurts. Because she is about to walk again, her first steps in 173 days.