High Jump On-Line Book‎ > ‎HJ Technique‎ > ‎The Approach‎ > ‎Your Approach‎ > ‎Adjustments‎ > ‎

Curve Radius

Adjustments to your rotation about the bar via your curve radius
Using High Jump Coach 2010TM and working from any properly executed HJC 2010 approach, adjusting the curve radius is easy.

Why Adjust Your Curve Radius?

All other things being equal, your curve radius controls your rate of spin about the bar. If the rate of spin about the bar gets you horizontal at the apex (peak) of your flight, then your lower body will spin out of the way of the bar on your descent into the pit. Thus, the adjustments you make to your curve radius depends on how far from horizontal you are at the moment you reach the apex (high point) of your flight.

How much adjustment should you make?

The formula is simple:

for each degree of rotation you are short of getting horizontal as your Center of Mass (CM) reaches the apex of your flight, reduce your curve radius by 1%.

For example, suppose you  are rotated 8 degrees short of horizontal at the apex of your flight, then you would need to reduce your curve radius by 8 %. Thus, if the radius of your current curve is 20 feet, the radius of your new curve would be less by 1'-7" or 18'-5'.

If you are over-rotated, you add 1% to your radius for each degree you are over-rotated. Just the opposite of what you did for under-rotation.

Then Just enter the new radius into HJC 2010, mark your new approach on the approach apron, and jump.