when we were practicing the knees, i could land them pretty good. and when we were told to put power into kneeing the practice pads, i found it easier to pull down on my partner and put more power into it. I think its because i was too busy trying to get the "right" hand placement to worry about anything else. Ill try it again next time, both ways.
I have another question, which i doubt there is an exact answer for, but how long did it take you to get used to having the weight of thai pads on your arms? we usually do half an hour of practicing, and the past four classes weve spent ten minutes using the thai pads, and about half way through, my left arm just loses all strength and can barely keep it up. I can keep the right up for the whole time though. Dunno if its because im not used to the weight and just need to get used to it, or if im just weak on the left side.
You're right there isn't an exact answer. Its just a matter of the isometric conditioning or the arms/shoulders/traps. You're holding up a weight of between 3 and 5lbs, depending on the brand of pad for ten minutes straight. Its innevitable your arms will go all weaksauce eventually. After a while, you'll adapt and your arms won't tire as quickly, but will eventually, nobody's conditioning is that good! As a matter of fact the conditioning aspect is one of my favorite parts of holding the pads for someone.
As for weakness on one side opposed to the other, if your a righty, your right side will be naturally more developed than your left side. The bones, muscles, tendon, etc are denser than on your "off-side". Its just a natural aspect of human physiology that can be pretty effectively overcome with proper conditioning, but assuming you are symetric in your workouts, your right would always be stronger/more developed than your left.