I am currently not an LEO. However, I am in FBI agent applicant purgatory waiting on Phase 2 and in the hiring process for the DEA, 2 local law enforcement departments, and waiting on 1 academy start date. I have passed all the of physical tests without any back pain or injury. (Although I did stress fracture both tib/fibs in both legs for the FBI Phase 1 PT test) I had a herniated disc in my back (L4/L5) causing me sciatica at age 25, got a microdiscectomy back operation at 28. I am about to turn 31 in a month. NOTARPilot, had some great points, focusing on core strength, correct lifting, etc.
Knowing what I do now, I would have done these things differently.
1. Not waited so long to get the operation (mind you I had sciatica)
2. Not listen to any doctor that told me, 'We need to fix YOU, not your back", thus implying to deal with the pain and avoid operations at all cost.
3. My 3rd doctor who is amongst the best in neurosurgery at UCLA Medical Center suggested that physical therapy wasn't needed. However, he had no knowledge of my specific life goals, so I would recommend therapy after surgery just to keep your tendons, calfs, etc. from shrinking and tightening up as this can cause lower leg stress fractures when it comes to sprinting and running.