He's right. Just check with your physician first.
Long version:
Years back, I injured my lower back due to stupidity (bending sideways with a heavy object, instead of keeping my back straight and lowering straight down with my legs). Ended up with a slipped disc.
The slipped disc put a serious cramp on working out. It got to the point where I would feel the disc slip out multiple times a day, every single day. Fortunately for me, it never put me down. It would ache, my back would stiffen up and I'd be walking like Frankenstein, but I was still mobile, and I eventually learned how to carefully manipulate it back in place.
I lived with this for years (too stubborn to get back surgery etc.), and as mentioned the back injury (along with a shoulder injury) put a serious cramp on working out.
A few years back, I decided enough was enough. I'd lost a lot of the strength I'd built-up to at one point, from not working out due to the injuries and some other health issues I'd been dealing with, but I REALLY missed the strength I used to have, so I decided to see how much of it I could regain.
I was making decent progress, but was not doing deadlifts because of that lower back issue.
I noticed two issues though:
1) As I increased weight on squats, I realized that while my legs were getting stronger, my lower back was giving me more and more problems. I realized that the slipped disc was slipping out of place at the bottom of my squats, and the heavier I squatted, the more stress that out-of-place disc resulted in, causing even more issues.
2) because the disc would slip out at the bottom of the squat movement, I tried avoiding squatting deep. The bottom of my squats stopping at parallel, and even above parallel.
I also noticed that while my legs were getting stronger and I was squatting heavier, I was still having issues getting up from a full squat (eg. from things like adding air to the tires).
My knees (and the head of the quads near the knee) hurt when trying to stand back up, and I was getting up like a stiff, really old person. At first, I thought, "Eh, result of getting older". Then I considered, how can my quads be getting stronger, but still have issues with just my bodyweight from a full squatting position? Could it be due to me not training for strength in the full range of motion due to the other issues? I never had those problems when I used to squat deep.
I went back to the drawing board, and decided I needed to see if I could rehab my back and everything else. I knew my back was a lot weaker from avoiding straining it for years, but I also realized that because certain stretches, movements would immediately make that disc slip out, I'd also been avoiding stretches that did that, and had lost a lot of hamstring and hip flexibility.
I started with the stretches. What made the biggest difference was stretching my hamstrings and hip flexors, so I could squat deep while keeping my back straight and tight. As the hamstring and hip flexibility increased, so did my range of motion while keeping my back straight, with a slight arch of course.
It's that, "lift with your legs, not your back" concept. Strengthen the core to increase the stability and support for holding the spine in place, while maintaining the hip and hamstring flexibility to avoid the tightness that can pull things out of place.
Watch people with poor hamstring flexibility, poor hip flexibility, and poor quadricep range of motion. Instead of squatting down (even to pick up something light, like the newspaper from the ground), they bend their backs. When you already have back issues, that isn't helping.
I then started squatting again. First, with just bodyweight, but focusing on squatting all the way down. Yes, my knees and quads complained at first, but I kept at it.
I slowly increased weight while focusing on squatting all the way down (it took months to retrain my quads and knees for the flexibility and strength in full range movements, and that was AFTER taking months of stretching to regain the hamstring and hip flexibility), but as I did that, I noticed that getting up from a full squat was no longer a problem.
My knees stopped hurting from squatting down to air up the tires, and instead of getting up in super slow-mo (sometimes needing to use my hands on my thighs to push myself up, because my knees were stiff/hurting from that squatting position), the more weight I could do full squats with, the springier I could get up with just my bodyweight (must've looked like a loon after airing up my tires, then literally jumping up with a smile on my face).
I also started deadlifts again. Boy, did my back grumble at that. My back was so unused to it, that even light deadlifts ached, but I kept at it.
It took a couple of years, and I'm still not back to peak strength, but my back no longer bothers me. That disc rarely slips out of place, and if it does, it doesn't slip out anywhere even close to as much as it used to.
Strengthening my back has helped hold it in place better (along with increasing my hamstring and hip flexibility to avoid pulling it out of place, and strengthening my legs in the full range of motion to avoid the 'bending at the waist/back to pick things up to avoid squatting all the way down', which just added to the issues). The stronger I got, and the heavier I could deadlift, the less my back bothered me.
Increasing overall core strength (abs, obliques, serratus, as well as those spinal erectors), made a huge difference in the support for the spine.
I'm not the first one to have experienced this either. I know of numerous other guys with back issues, who've managed to alleviate those issues by strengthening their backs. I should've done it a long time ago.
Just remember that proper lifting form is crucial to avoiding injury and/or exacerbating any issues.
"So about that 5 carat diamond...something happened in the post and it turned into powder..."
