Other devices, disclosed in the prior art, teach a rigid system. Such a system may be in the form of a surface that the user's presses against. The problem with such a device is that when removed, the ability of the user to "lean" against the device is removed, and the absence of the positive reinforcement causes a user's swing to revert back to the same problems that the swing aid was supposed to address. The soft surface of the present device acts as a "reminder" but not a constraint. The object the user must achieve is to swing through the golf swing without his or her lower leg pressing into the soft sides of the cradle. This practice makes the user more cognizant of the position of the knee and lower leg as he or she swings through. As the device is used and practiced with, the user learns to work to keep his or her knee and lower leg in proper position, and not rely on "leaning" against a device. In this way the user learns what proper positioning feels like, and is more likely to repeat the position when the device is not present. The prior art cited, in particular U.S. Pat. No. 5,591,090 to Kauffman prevents sway with a rigid forward structure. The use of the inner curved, circular configuration in the present invention corrects two golfing swing problems, being lateral sway and the straightening of the trailing leg.