Have a look at these and try adapting some of the techniques (the jumping off the cliff and flying into the wall ones would be most useful for what you want). http://www.nccinema.ch/etutorials.html
Bascially you can green screen the person you want to be thrown up in the air. Have them jump and land as if blasted. Then when you green screen them over your background/explosion move the quad with the person up and then down during the part when they are jumping. This will make their jump seem much larger. You could use the explosion to block out the first few frames to hide the knee bend as they jump.
Alternatively you use a mini trampoline to get the height. The explosion would be used to cover the trampoline. The person would need to land on mats to break their fall so you would have to film their landing as a second shot. This could be just of them falling from a standing position with burnt clothes, bloodied make up effects etc. Cutting between the two shots - person flung into air CUT TO to person hitting ground bloodied - would give the scene a bit more energy as well.
Oh yes and try not to double post - if you have forgotten something or wish to amend your post you can just use the EDIT button. Good luck!