Vive Foot Rocker - Calf Stretcher for Achilles Tendinitis, Heel, Feet, Shin Splint, Plantar Fasciitis Pain Relief - Stretches Strained Leg Muscle - Ankle Wedge Stretch Improves Flexibility

Yesterday while hiking, I saw someone stand by their car, with their leg on one of these things. I figured it was for stretching.