With our commercial Reformer range, each Reformer has several stoppers - their job being to control how far the carriage travels into the springs.
For shorter legs, either zero or one stopper would be appropriate to achieve a 90-degree angle between the ankles, knees and hips when lying on the carriage. For those with longer legs, one to two stoppers allow the legs to form a right angle whilst preventing the carriage from closing too far to the foot bar.