Abstract: A teaching and practice device for improving a golfer's swing and alignment that eliminates sway. An extensible base adapted to be placed upon the playing surface is adjusted to the desired playing width and positioned substantially parallel with the desired target line. The base comprises a pair of axially displaceable brackets that can be moved with respect to each other to dispose the base at a desired length, normally the width of the golfer's shoulders. Each of the base brackets comprises a horizontal portion for contacting the playing surface and an integral vertical portion. The vertical portions comprise elongated slots adapted to be registered with one another to facilitate length adjustments. Foot control arms pivotally associated with the base at its opposite ends firmly contact the outside edges of the golfer's feet and prevent improper leg movement during the golf swing.