What leg to push off of. Effect of heeling on forward velocity.

[Idiot Savant]

I thought I'd throw in two cents about using the legs with a double blade.
I hope I've got this right because it's been a several weeks since I've been on the water and even longer since I was paying attention to what I was actually doing while paddling.
The starting position is with both legs bent a little. With each stroke I push/straighten the leg on the side I'm paddling on. Since you switch sides with each stroke, one knee is up and the other down with each stroke. There is some rotation of the hips involved.

 

[Glenn MacGrady]

I thought I'd throw in two cents about using the legs with a double blade.

The starting position is with both legs bent a little. With each stroke I push/straighten the leg on the side I'm paddling on. Since you switch sides with each stroke, one knee is up and the other down with each stroke. There is some rotation of the hips involved.

That's right.

Think about the mechanics from the point of view of your hip rotation. To forward stroke pull on the right side, you invoke your torso by rotating your right hip aft (clockwise). That will naturally straighten your right leg.

In addition, you assist the clockwise rotation of your hips and torso by pushing with your right leg against the foot bar. That push transmits extra force up your right leg, into your clockwise rotating hips, into your torso, into your shoulder, down your right arm, and finally into the backward pull of the paddle face against the water.