Keeping the left leg straight squat back and to the right. Lower the hips through a full comfortable range of motion. The right knee can drift slightly forward of the right foot, be kept in line directly above the right foot, or be lined up slightly behind the right foot, depending upon what's most comfortable to the athlete. The back should remain arched and the head should stay up through performance of the exercise. Return to the starting position and then repeat in the opposite direction until the desired number of repetitions has been completed. Common Errors Allowing the back to round rather than maintaining an arched-back position during performance of the exercise.