This is a runners calf stretch to help you improve your ankle dorsiflexion. Find a comfortable stretch with your feet straight ahead and hold for 1-2 minutes. After your stretch begin your PAILs contraction by pushing the ball of the foot into the ground and ramp up slowly (20, 40, 60%). Hold for 10seconds. Release your contraction and slowly start to bring the ball of your foot to your knee engaging the shin for your RAILs contraction. Ramp up slowly and hold for 10 seconds.