Now that you have finished your initial body rolling, gently draw your knees to your chest, holding them together or slightly apart, whichever is comfortable, as best you can. Hold for a count of 30. Now, gently rock back and forth on your back. Do not roll over to your side like you did in the first warm up exercise. This movement is done on a flat back. Do this 6-10 times, more if  you like.  In a second variation, hold your knees and mimic a walking motion while you are doing the gentle rock described above with your head slightly elevated or flat. Your knees can be slightly apart or wide as is comfortable for you. You’ll feel this massage in your upper and middle back as well as the lower back  while warming up the hip flexors.