You can begin gently stretching your hamstring right away by doing the standing hamstring stretch. Make sure you do not feel any sharp pain. You should feel only a mild discomfort in the back of your thigh when you are doing this stretch.
After the hamstring stretches become easier, you can do the hamstring stretch on a wall and the standing calf stretch. It’s good to stretch your calf muscle because it attaches near where your hamstring ends.
When the pain is gone, start strengthening your hamstrings using the following exercises.
You can challenge yourself by moving the chair farther from the door to increase the resistance of the tubing.
After your hamstrings have become stronger and you feel your leg is stable, you can begin strengthening the quadriceps (the muscles in the front of the thigh) by doing lunges and the slump stretch.