Optimum Leg Length

Does anyone have any information regarding the optimal leg bend for a ski?

I am aware of the various rules of thumb (enough room for a fist under the knee) and (knee at navel height) but they both seem like there is a lot of room for variation.

When ordering a fixed leg length ski manufacturers must have a guide to determine what the optimum length must be. Is there some equation that they utilise using a known angle to a specific leg length. If so what is the angle?

Any help or insights would be greatly appreciated.

I've asked a couple of folks about this and there doesn't seem to be a definitive formula.

Basically you should be comfortable and able to push your foot against the footplate when you rotate.

As an example I paddled a new ski this weekend and had the leg length too long. I couldn't push hard against the footplate without stretching my leg so far the back of my knee was pressing against the bottom of the cockpit.

I adjusted it - but too far and I then felt a bit twitchy in the boat. So the ideal is somewhere between those two positions!

If I could adjust my leg length I cuold be much taller....