If you wake up stiff and sore but loosen up as the morning goes on, your mattress is a prime suspect. The right mattress won’t cure an underlying back condition, but the wrong one can create or worsen back pain, and replacing it is one of the most direct changes you can make. Here’s how to choose well, without falling for the old myths.

A note before we start: persistent or severe back pain deserves a professional opinion. This guide is about choosing a mattress, not a substitute for seeing a doctor or physiotherapist.

The “firm is best for bad backs” myth

For decades, the standard advice for back pain was “sleep on the firmest mattress you can find”: some people were even told to put a board under the mattress. Research has moved on. Studies comparing mattress types have generally found that medium-firm mattresses give better outcomes for low back pain than very firm ones, because a rock-hard surface leaves your lumbar spine unsupported and loads pressure onto your hips and shoulders.

What your back actually needs is neutral spinal alignment: the same gentle S-curve you have standing upright, maintained while you sleep. That takes a mattress firm enough to stop your hips sagging, and forgiving enough on the surface to let your shoulders and hips settle in.

What to look for in the mattress

1. A supportive core that resists sagging

Sagging in the middle third of the mattress is the classic cause of mattress-related back pain. Your hips drop, and your spine bends all night. Look for a quality spring system or high-density core, and pay attention to designs that reinforce the centre: Restonic’s well-known Marvelous Middle construction strengthens exactly the zone where body weight concentrates. Browse the Restonic range to see it across their Pocket, Supreme and Premium lines.

2. Medium to medium-firm comfort: adjusted for your weight

Start from medium-firm as the evidence-backed default for back pain, then adjust: lighter sleepers (under ~60 kg) often do better one step softer, heavier sleepers (over ~100 kg) one step firmer with a higher-density core. Our firmness guide covers this in detail.

3. The right feel for your sleeping position

Side sleepers with back pain need slightly more surface give (medium) so the shoulder can sink and the spine stays straight; back sleepers do well at medium-firm; stomach sleeping is honestly the hardest position on a lower back, if you can’t change the habit, choose firm to keep your hips level.

4. Motion isolation if you share the bed

Broken sleep makes pain worse. Pocket spring designs, where each spring moves independently, stop a restless partner transmitting movement across the bed. Most of our premium ranges, including Genessi and Beyond Sleep, use pocket coil systems.

Signs your current mattress is the problem

Pain is worst when you wake and eases within 30–60 minutes of getting up
You sleep noticeably better in guesthouses or hotels
There’s a visible body-shaped dip, or the mattress is older than 8–10 years
You’ve started sleeping diagonally or migrating to “the good side” of the bed

Two or more of those, and a new mattress is very likely to help.

Don’t forget the base

A new mattress on a worn, sagging base inherits the base’s problems, and can void the mattress warranty. If your base is as old as the mattress it carries, replace both together; a matched bed set is usually better value than buying separately.

Test it properly before you buy

Lie down in your normal sleeping position for a full five minutes. On your back, slide a flat hand under your lumbar curve: a big gap means the mattress is too firm for you; if your hips have sunk below your shoulders, it’s too soft. Visit our Randburg showroom at Northlands Deco Park and test the ranges back to back, bring your pillow if you want the truest picture.

Shortlist in two minutes

Our mattress finder asks about your size, sleeping position, comfort preference and budget, and shortlists suitable mattresses from our range. Down to two candidates? Compare them side by side. Or browse all mattresses and filter by comfort level, and if you’d like advice for a specific back issue, WhatsApp us; matching sleepers to mattresses is what we do all day.