Medi-Dyne ProStretch Single Make stretching easier and more effective with the Medi-Dyne ProStretch Single. Designed to stretch calves, hamstrings, Plantar fascia, and toes, the ProStretch Single holds your foot in the optimal position for proper stretching. This allows for a biomechanically accurate and efficient stretch that can work the lower leg muscles more effectively than traditional stretching. Stretching with the ProStretch Single may help increase flexibility and range of motion while relieving and strengthening tight calf muscles, Achilles tendons and foot muscles. Fits adult shoes up to size 13. Includes a detailed stretching guide with targeted gastroc, soleus, Achilles tendon, hamstring, plantar fascia, and toe stretches.