shoulders, traps, quadriceps (as knees are slightly flexed)
instructions
preparation
execution
variations / comments
Stand on platform, heels extending off. Place shoulders under padded lever. Stand upright, knees and hips straight and grasp the sides of padded lever or handles.
Extend ankles to raise heels as high as possible. Bend ankles until calves are stretched. Repeat.
Alternatively keep knees slightly flexed throughout motion.