Britain has become a nation of hunchbacks. Although this side of the Channel, they labour not in bell towers but over computer keyboards – men folded into shapes a spine should never endure. No wonder we sacrifice around 31m work days to back and neck pain every year.

The human body evolved over millennia to stand upright, its bones and muscles seamless when they’re unfurled. Yet the modern office conspires to constrict, to roll shoulders forward and tip hips back, your joints locked in positions that fight their anatomy. Your daily transition from bed to office chair to sofa to bed sends tingles down your arms, or lights bonfires in your lower back.

“The comfortable slouched position isn’t the best for your body, even though it’s the easiest,” says Leo Savage, personal trainer at London’s Third Space gym. Spend too long curled up and your ligaments and tendons, which your anchor muscles and bones, contract. You’re pulled into tighter shapes, your spine curls, your shoulders slump forward and put pressure on your neck. You seem to physically diminish as poor posture lops inches off your height.

After years spent in supplication to your screen, you need to see the light. “Your postural problems can lead to extra strain on your muscles and soft tissues,” says Savage. “This in turn can lead to chronic injuries which can be very painful.” Muscle weakness and imbalances can make that blaze up your back permanent. You need to stand up, and not feel the burn.

First, try swapping your conventional desk for a sit-stand version (£295, varidesk.com) and build from 20-minute stints until you’re spending most of the day on your feet, with your body as evolution intended. As you spend more time upright, you’ll notice discomfort in new areas as long dormant muscles wake up. You core, glutes and delts will be weak, your joints inflexible. Which are as bad for your physique as your health.

“When your spine is out of alignment, this transfers into everything you do in the gym,” says Savage. “When executing exercises with a poor posture, you are then led to recruit different muscles to compensate for your imbalances.” You need to focus on your posterior chain – those muscles behind that pull your body back and up to counter slouching. Work though this circuit three times a week to unlock your muscles and beat back pain for good.

Back-Strengthening Circuit

Mobility

Sitting means muscles aren’t stretched, so become inflexible. You need to stretch them out so you’re in the right position at rest, not hunched forward.

Work through one minute of each stretch, then move straight into the next.

Thoracic Stretch

Sit on the floor with a foam roller behind you then lie back until it supports your upper back. Brace your core to lift your buttocks off the floor and – with your feet flat and hand behind your head – roll slowly back and forward.

This releases the tight muscles that pull your shoulders forward, so you stand more upright.

Hip Opener

Start from standing, then lunge forward until your back knee is touching the ground. Push your front knee out to the side, trying to rest it flat on the floor.

Push your hips forward to feel the stretch then repeat for the opposite leg. Tight hip flexors tilt your pelvis forward, which arcs your spin. This stretches them to get rid of the kink.

Lumbar Roll

Lie on your back with your feet flat on the floor, knees touching and bent at 45 degrees. Keep your shoulders flat and tip to one side, until your legs are parallel to the floor.

Hold then slowly repeat on the other side to stretch out a tight lower back.

Strength

Your muscles are paired, working against each other to move your body in different planes. Where imbalances arise, your body is forced in one direction. The longer you hunch over your keyboard, the more your body wants to slouch forward. Strengthening the muscles that straighten your spine fixes that poor posture and alleviates pain.

Perform 60 seconds of each exercise then move onto the next. After the bridges rest for 60 seconds. Repeat the entire circuit four times.

Plank

Support your body on your toes and forearms, keeping your core locked to hold your body flat. There should be a straight line from your shoulders through your glutes to your heels.

Back Extension

Lie flat on your stomach with your chin resting on your hands. Lift your head and legs together, holding at the top of the stretch, then slowly lower.

Bridges

Lie on your back with your feet flat on the floor, knees at 45 degrees. Tense your glutes and core to lift your buttocks off the floor, keeping your shoulders on the floor. Hold then slowly lower.