This exercise stretches the muscles at the back of your calf.
It also stretches your Achilles tendon... which is your heel cord.
Here's how to do it.
Sit at the edge of a chair.
Extend one leg out in front of you, with your heel on the floor and your toes pointed up.
Keep your knee as straight as you can.
Place a belt or strap around the ball of your foot.
Gently pull your foot toward your body, until you feel a stretch in your calf and the back of your heel.
Make sure to keep your leg straight and your toes pointed up toward the ceiling.
Hold the stretch for 15 to 30 seconds, and then slowly release the belt or strap.
Repeat the stretch 2 to 4 times on one side.
Then, switch legs and do this exercise 2 to 4 times on the other side.
Some soreness or discomfort may be expected...
but stop doing an exercise if you have increased pain.