I'd like to see your video reference if you have one. The poses are stiff but you got the main idea down, but the timing doesn't work at all. It's also very floaty and weightless.
If you look at the reference, you can see that every step is very fast, you need to be quick on your feet in MMA, boxing or other martials arts. Right now the feet in your anim are slow, linear and they slide around. A good idea is to place key poses when there's contact with the ground, if you nail the steps to the ground and the impact of the guy falling, you'll get your weight. Look at the timing on the punches at the end, they're very powerful, use quicktime or http://anilyzer.com/ to scrub your reference frame by frame and see how many frames there are for the anticipation and the hit and the settle.
Also, the timing is a little jumpy when it comes for the character to be quick and such. Feels too floaty and there's also about the issue that you can't really feel the weight behind the kick and the force of the impact on the other model. Try to make the other model react properly to a kick that could bring you down. Maybe turning the head faster followed by the whole body could work and to compensate for how you have your final shot set up you can maybe make the character try to cushion the fall with his arms to then turn around and receive the beating out of the other model.
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Front Kick Knockout - Updated 2 from Louis Veillette on Vimeo.
Here is an updated version of the same animation.