This is my spine. Take a look at L5 (the sharp bend). You might notice the disk is dark, you might notice the piece sticking out the back. That currently hits my spinal cord on occasion, presenting as sciatica.

I tweaked it wrecking motorcycles, sitting at a desk for eight hours a day and exercising inappropriately. I am currently treating it myself.

Got sciatica? Here's what I know so far. YMMV. Hamstring exercises, good for leg symptoms, very temporary. Extensions, good for centralizing pain into the back. Posture isn't everything, it's the only thing. When yo mamma tells ya stand up straight, do so. I can ameliorate my symptoms spectacularly by pushing my shoulders forward and my head back. The 'string from the top of the head' visualization helps too.

Dunno as I can prevent it, I just wanted the assonance. Well, I am preventing the worst symptoms. Exercise is important. To get there NSAIDs help alot. Diclofenac is the best I've found. Ibuprophen, OK, Aspirin, barely touches it, Acetominaphin/Paracetemol... varied. If I'm really in pain the latter two can help. Generally I'm not, it's an incredibly irritating sensation words fail to describe. Avoid experiencing it if you can. If it's too late for you see if you can find Diclofenac. It is very anti-inflammatory and doesn't rot your gut or liver. May lead to minor cases of death, but then, what doesn't?