VR controller cameras can help you play Feet Saber | Laptop Mag
These researchers came up with a solution for one of VR's biggest issues: tracking your legs | CNN Business
Amazon.com: Skywin VR Tracker Strap for HTC Vive System Tracker Puck (1 Pack) - Adjustable Strap for Hand Foot Object and Full-Body Tracking in Virtual Reality : Electrónica
EOZ Premium VR Strap - For Feet (Medium) - In stock? Shipped the same day!
Adding tracked feet to VR is very, very simple | KitGuru