Any set of duty belt suspenders is a wise investment if you have back problems. Blauer makes a set I've heard good things about.
Also re arrange your belt and clear any handcuffs/whatever from anywhere behind 8 o clock and 4 o clock. Also put NOTHING in the rear pockets/sap pockets while seated, not even wallets or thin gloves, sitting on the uneven stuff for a shift is very bad for your back. Add one of the padded back supports as well, you can find them in leather or nylon to match your equipment, there are many different brands. You will likely notice a huge difference with just those changes.
Lots of guys I know are getting the MOLLE vests for 'back pain' then loading them up with equipment, which is silly and counterproductive if eliminating back pain is the real goal. I wore a MOLLE vest/carrier in the army loaded with shit on the front and it was horrible for my back. Good hiking packs use a waist belt for most of the load and stabilizing support shoulder straps; so should your duty gear.
When I started this job my back and knees were already jacked up from the army. I worked in a place that had traditional uniforms with no cargo pockets, just sap pockets filled with crap, and nylon fake leather Bianchi belts with no stretch to them, wore two single cuff cases on either side of my spine per policy. I developed sciatica quickly.
Now I have cargo pockets and keep nothing in the rear pockets, I use a safariland drop holster and wear just one single cuff case at about 3:30 right up on the attachment point for the drop, so there is nothing on my back but keepers. I also switched to a real leather belt which I prefer to anything nylon as I prefer the way leather stretches and molds to your body shape over time.
My back issues are almost entirely gone with just those changes. If they get worse I will invest in a suspender set.
ETA: If your department has a shitfit about suspenders any competent uniform tailor can add access points to a traditional class B shirt that lets you run them under your shirt, but over your vest. Lots of guys at my old agency did that since we had anal uniform policies.