Many of us spend more time sitting on an office chair than anything else – often upwards of eight hours a day. So a well-designed, comfortable seating option is essential, both for improving posture and performance, not to mention keeping a bad back and other types of pain such as neck ache at bay.

According to Mark Steel, Managing Director of Streamline Office Services, there are three things to be mindful of when buying one. “Ideally, look for a chair with lumbar support, seat depth adjustment and a free float tilt mechanism, as these ensure that the chair can be adjusted to suit you as well as encourage movement. And for the same reasons, although it may cost you more, it’s also good to choose one with armrest adjustability and different size options. Second, find a supplier who will show you how to use your chair and fit it for you on delivery. Third, remember a good ergonomic chair should have a warranty of at least five years and should last well beyond that.”

While you can find office chairs that are classed as ergonomic for as little as £45, one of the most common mistakes people make is buying cheap, he says. “It’s a false economy, given how vital a good quality ergonomic chair is for your work. Another easy mistake is not using a chair correctly – the most ergonomic chair in the world is of little value if you are not using it properly.”  Never buy on looks alone, he adds. “Some of the most stunning office chairs aren’t designed for the way we work now in the digital age.”

In order to position yourself correctly in your office chair and avoid back pain either now or in the future, you need to first adjust the height, back position and tilt to ensure your back is well supported, with your bottom pressed against the back of your chair, your lower back slightly arched and well cushioned and your knees slightly lower than your hips. Ideally, your feet should be flat on the floor – or you could use a footrest if you find it more comfortable.

Your wrists and forearms shouldn’t tilt up or down – but instead go straight out in front of you – which helps prevent RSI (repetitive strain injury). And your screen should be an arm’s length away, with the centre of the screen at eye level, which helps prevent neck pain. Your keyboard should have around four to six inches at the front of the desk so you can rest your wrists when you’re not actually typing and your mouse should be as close as possible.

Adjust the armrest of your chair so that it lifts your arms very slightly at the shoulders. This will take some of the strain away from your upper spine and shoulders, as well as helping to prevent slouching. Finally, move around and take as many short breaks as possible so that your muscles get a chance to relax from time to time.