-• Size of the base of support in the direction of force or impending force: In general, increasing the size of the base of support increases stability. In preparation for an impact, we tend to spread our feet apart. We do so, however, in the direction of the force. If you were about to be struck from the front, would you widen your base of support by abducting at the hips to spread your feet apart to the side? Probably not. Most likely you would increase your base of support by staggering your feet front-to-back, or in an anterior-posterior orientation. Merely increasing the size of your base of support will not necessarily make you more stable. The increase must be made in the direction of force or impending force. Increases in base of support can be made by placing the feet in a certain position, as in the previous example, or by adding ground contact points. Additional contact points can be added by using other body parts, as when a baby creeps along the ground on hands and knees or when an athlete assumes a three-point or four-point stance (figure 6.7). Older or injured persons also can enhance their stability by using a cane or crutch to add contact points to the system, thereby increasing their bases of support (see figure 6.6c).