The Science of Not Falling Down

Officially, balance is the control of the postural equilibrium required for optimal performance of the human body. Less officially, we think of it as the ability to walk, bike, surf, wear 4-inch heels, and climb stairs without falling down.

Sensory input from our visual, vestibular (inner ear), and touch receptors provide information about our position in space. The brain then signals reflexive or voluntary muscle actions that control our movement. Like flexibility, we can think about balance as static or dynamic.

We use different strategies to maintain balance.

Balance training is important for everyone—whether you’re rockin’ those 4-inch heels, running patterns on the field, or picking your way through a muddy section of the trail. And there’s no wiggle room for iffy balance when you’re training with free weights or facing down the balance beam on an obstacle course race. Next time, we’re going to take our base of support into the gym and test it out.


Center of gravity (COG) is the point our weight is evenly distributed around. The center of gravity is typically found in the sacrum, though its exact location varies by gender, body shape, body size, and even age. Our center of gravity shifts around as we move or add external resistance—when a sack of groceries, for instance.

Base of support (BOS) is the two-dimensional distance between our points of contact with a surface. For example, when standing with your feet 12 inches apart, the base of support is the area that your feet cover plus the area between them. Moving your feet closer together shrinks your base of support. A small base of support means more effort will be required to maintain balance.