Why my left leg quadriceps are bigger that my right?

even though i am right footed (soccer), my left quad was a bit bigger, you should start workin out (if you are old enough), use the same wait for both legs even if one is stronger, eventually both legs will be equally as strong and the same size, my theory for this is that when i sprint, my left leg is doing most of the pushin, and when i kick, my left foot has to hold all of my weight up, i dont know but know my legs are the same size

Probably because you recently hurt the other leg so your left leg has been picking up the slack. :) Also, just because you are right handed doesn't mean you are right legged. My brother is left handed but right eyed and right legged. You can tell by this simple test (will you are NOT injured) stand with your feet together and fall forward. The leg that goes to catch you first is your primary. Also, sometimes you favore your 'prefered' side for precise things and use your unfavored side more for base things, which can make the off side stronger. I am strongly right handed but I use my left arm to carry anything heavy, to leave my right hand open to use for fine details like keys and doorknobs, so my left arm has always been stronger.

think about this?...if you someone slice you from head to toe and line your two body halves together, most of all your body will not line up the same ...all bodies are not symetrically align...i have injuries in the past and after that its normal to have one body part longer or fatter than the other...you try to have therapy to regain strength in your limbs but one seems to always be stronger or weaker than the other...After injury or accident thats a given and you learn to live with it. you are not perfect but you can adapt to the strengths and weaknesses right ? Since I'm a woman, you know that our breasts are not even. One seems to be bigger than the other. My past partners told me they dont seem to notice but I know that my right is larger by 1/2 inch ...its like with men some men have one testicle larger than another ...its normal...its the way you were made...your body shouldnt be the issue here...if you are loved for you rather than your appearance, thats all that counts...

For the right handed persons,the body parts on the rightside are generally bigger and stronger.

You are probably favoring the stronger leg. You might want to see a doc so he can get you some rehab.

use it or lose it concept. when your right knee was hurt, you didn't use that leg and its muscles so they must have shrunk.