Balance in Sport

Balance in Sports

Definition

• Balance is the ability to neutralize forces that disturb equilibrium.

Types of Balance

• Static Balance: The ability to hold a stationary position. E.g., handstand, swimmer on blocks.
• Dynamic Balance: The ability to hold a moving position to execute an outcome. E.g., surfing, skateboarding, kicking a ball.

Factors Affecting Balance

• Base of Support (BOS): The greater the base of support, the greater the degree of stability.
• Mass: The greater the mass of an object, the greater its stability, assuming other factors are equal.
• Line of Gravity (LOG): The closer the line of gravity is to the limits of the base of support, the less the degree of stability.
• Movement is easier when the line of gravity falls outside the object’s base of support.
• Height of Centre of Gravity (COG): The higher the centre of gravity above the base of support, the less stable the object.
  • Low COG = increased stability
  • High COG = decreased stability

Centre of Gravity (COG)

• Theoretical point in an object where all mass is equally distributed; can be inside or outside the body.
• Standing still: COG is in the abdominal cavity, about 6 inches above the pubis symphysis.
• COG position changes as body position changes.
• COG position determines body balance.
• To approximate COG, draw a box around the object and draw diagonal lines through the box.

Line of Gravity

• Imaginary vertical line passing downwards through the centre of gravity to the ground.

Manipulating Balance for Sports

• Decreasing stability for quick movement:
  • Decrease the size of the effective base.
  • Displace the centre of weight quickly outside the effective base (move the line of gravity close to the base of support).
• Increasing stability:
  • Increase the size of the base of support in the direction of the oncoming force
  • Horizontally positioning the COG near the edge of the base of support on the side of the external force

Sports Requiring Balance

• Low Balance: Sprint starts (swimming, athletics), tennis (service reception), sports requiring quick lateral movement.
• High Balance: Wrestling, weight lifting, collision sports.