Purpose: Many swimmers lack anterior and posterior sagittal plane stability, demonstrated by poor dolphin kicking or excessive lumbar spine arching. This exercise is a regression from the hands over head partner pull: http://www.swimmingworldmagazine.com/lane9/news/ASCAEducation/33441.asp. Directions: Lie on your back and have your knees bent. Have a partner loop a towel around the back of the shins, then have tighten your abdominals and have your partner pull the towels in the direction of your upper thigh (femur). Try to not let your back arch during this exercise. Hold for approximately 5 seconds, for 5 - 10 repetitions.