Dr. Elara Vance had spent twenty years listening to bodies lie.

“Your socket alignment is off by four millimeters anteriorly,” she said. “Your hip extensors are compensating at 340% normal load. You’re a fracture waiting to happen.”

The skeleton glided. Joint powers flowed like a smooth river. The ground reaction force arrow pointed straight through the center of mass—a perfect, golden line of efficiency.

She saved the project file: Leo_Park_Fixed.v3d .

The engine chewed through the motion capture data. On her left monitor: raw marker trajectories—shiny pearls tracing Leo’s spine, hip, ankle. On the right: Visual 3D’s magic —a computed cascade of joint angles, moments, and powers.