I got back into training about 2 months ago, having purchased a solid olympic bar squat/bench setup.
I decided I'd start on the 5x5 workout because I've read so much about it, and it eases your body back into working out.
Anyhoo, 5th week in, everything was going fine, but at some point after one of the deadlift days (I had 70kg on the bar) I felt a pain in my left lower back, radiating down my left leg. It disappeared and I stretched my hips quite a bit and gave it a few days off, but jumped back in (probably too soon).
I was down in the garage starting where I left off and got through the warm up squat sets easily, then I got through the first work set easily (55kg on the bar - I find it easy to lift, but obviously my lower back doesn't) and on the second set on the way up I just felt this agonising ping in my lower back and was barely able to re-rack the bar. Anyway I had to wait in the garage until my girlfriend got home from work. Then my brother had to come over to help me up the stairs. I was completely out of action for about 3 days with bad pain through my left lower back, hips, and down my left leg.
My GP said I'd most likely torn a muscle (the fv(k?) because there was so much guarding going on down the left side of my spine, and I'd herniated a disc. He said to take it easy, take analgesics, painkillers, etc. Give it a few months before you do any load bearing exercises with your spine again, and be very careful with your form.
Anyway it's been about 3 weeks and it's fine now. I was told in most cases the herniation sort of "slips" back into place between the vertebrae on it's own, which I guess has happened.
Meanwhile, my girlfriend's father, who is also a GP, and did the first Degree in Sports Science that became available in the UK in the 70's, is pretty old school in his thinking. He said (DON'T BITE MY HEAD OFF, I'M JUST REPEATING WHAT HE SAID) the human body isn't really supposed to lift huge amounts of weight and I shouldn't be aiming to do so anyhow. It's bad for the our joints and the ligaments can't adapt as well as the muscles. He said stick to higher reps - 20-25 of a lower weight. One analogy he used which I did appreciate was that of our friend paleoman. He said "when the tribesmen went out hunting, one man didn't carry the kill home by himself. They all helped drag it back together, or cut it up and brought pieces back. It's similar to what I'm suggesting. More reps of a lower weight".
So I'm 28 now, but from the ages of 3-16 was on prednisone (quarterzone) on dosages ranging from 5-80mg a day for a kidney disorder. Apparently prednisone can weaken your ligaments and give you early onset osteoporosis

I'm thinking maybe I should listen to my girlfriend's dad. I don't know how I'll ever have the confidence to squat again though after that pain.
Has anybody here had a similar experience and can tell me how they eased back into it? Can you guys suggest stretches or exercises to strengthen the lower back to prevent something like this happening again?