Insight into Injury

This current Side Heel challenge has been much more difficult for me than the Front Thrust.  There is so much more involved and it just literally takes more energy to do 10 side heels versus 10 front thrust kicks.  The Side Heel also causes me pain in my one knee, which I believe is being caused by hyper-extension.  I've gotten some feedback on this and I've been working on some adjustments, but even so, after almost 800 kicks in the last 6 days, plus my regular training, its taken it's toll.  

I'm not sure if my kick has improved that much with this challenge, technically speaking, but I've taken this opportunity as a chance to try and pinpoint when I am experiencing pain, as well as when I'm not. 

Here's what I know.

• I don't seem to cause injury when kicking from horse.  Only from Bow stance.
• If I can really engage my leg muscles (ie. quads), less pain.  *This was some direct feedback I received and it has worked as long as I can engage those muscles.  This has proven more difficult than expected.
• If I pivot my base foot just a bit more than I've become used to, no pain.  This also seems to help me engage my leg muscles (as per my previous point) and seems to keep everything more aligned, right from my head to my heel.  I worry with this because I don't want to start venturing into back kick territory.
• The more power I direct to my heel, the less pain.
• The more I focus on chambering properly, the less pain.
• I have no pain in my left knee.  My left leg is my weaker side so perhaps I'm just not putting as much force into it.
• There is more pain if I get sloppy.  Ie. if I let things slide during the last couple of kicks in a set.
• The less stable I am, the more sloppy the kick.  I really need to improve my balance.
• I would describe it more as tenderness or tension rather than sharp pain.  And it's in the back of my knee, not really the joint.

From what I can tell there are a myriad of factors involved here.  But I have a feeling they are all connected to the same thing (engaging those muscles to avoid hyper-extension) and if I can make these adjustments, I'll be able to alleviate this pain.  The hardest part is consistency and being fully aware with each and every kick.