Which of the following are biomechanical principles for balance?

• A. The force that opposes motion between surfaces
• B. Stance, base of support (points of contact), center of gravity
• C. The energy stored due to height
• D. The turning or twisting force

Answer: (B)

Balance relies on keeping the body's weight over its base of support. The best description of this is stance, base of support (the contact area with the ground), and the center of gravity (the point where the body's mass is concentrated). Stance is how you position your feet and body to maintain stability. The base of support is the area bounded by your points of contact; widening it—by spreading the feet or lowering the body—expands the region that can contain the center of gravity and improves balance. The center of gravity is the single point where mass is evenly distributed; when it sits over the base of support, you stay upright, and you adjust your stance to keep it there during movement. The other ideas—friction, energy from height, and turning forces—affect movement and stability but aren’t the core biomechanical principles that govern balance.