You can do the hamstring stretch (exercise 1) right away. You can start doing exercise 2 as soon as it is not too painful to move your kneecap. When the pain in your knee has decreased, you can do the quadriceps stretch and start strengthening the thigh muscles using exercises 4 through 6.
Hamstring stretch: Do not round your shoulders and bring your head toward your toe. This will stretch your low back instead of your hamstrings.
Straight leg raise:
Weight lifting - leg extension:
Written by Tammy White, M.S., P.T., for Clinical Reference Systems