I sleep on my front and have never really been able to sleep on my back unless I was really hammered. Does it make a difference when it comes to inducing LD?
it really doesnt matter too much how you sleep, what matters is your mind, ive been lucid on my back and side, so that shouldnt be to much of a problem.
The idea that you can only lucid dream while sleeping on your back or any other position is a complete myth. The only sleeping position that you need to make sure you use is the one that’s most comfortable.
I’ve been told that you shouldn’t sleep on your back, as it’s “unnatural”. Sleeping on your side, or in fetal position is more “healthy”. But I’m not to sure about that =P
Personally, I used to only sleep on my side, but I’ve slept on my back ever since I broke my collar bone and HAD to sleep on it x3
I’ve read you can only be completely relaxed when lying on your back with your limbs apart as well, but I guess it’s all about experimenting for yourself 
I don’t think anything would affect your LDing directly negatively ^^