[ehnto]

Gravity acts over time, if you are slowly lowering it you could be expriencing the same force practically as on the way up.

The reason you don't do it for powerlifting is because you're more likely to injure yourself after a max effort lift (like a one rep max lift in competition). Since you exerted maximally on the way up and may struggle controlling it on the way down it while exhausted. All the other compound lifts in powerlifting end at the finish of max exertion so don't have that issue.

If you are only training for general reasons you might not run into it, but if you are a powerlifting athlete doing 5, 3 or 1 rep sets for comp then this is good advice.

[j33zusjuice]

It great advice for exactly the reason you stated. And in gyms that disallow dropping, you give minimal effort on the way down, just enough to not get kicked out.

If you’re hellbent on doing long eccentrics on your low back, do it on back extensions with light weights. I used to do them. I always regretted it the next day.