i just recently started doing legs again ever since college football and damm they are weak. im 6'4 250 and i pack a lot of upper body muscle and my legs dont match my upper body. well i started doing legs a few weeks ago and the day after i got this strain in my lower back that caused me to stay in bed for a few days and i couldnt walk. well i did them again last week and the next day again i felt some pain but not as bad as before. today is leg day again. i understand my lower back is very weak, but i need to know what kind of excersises to do to strengthen it back up. and i could surely use a good leg routine........any suggestions?