The next time you are seduced by an impeccable room with a luxury couch, remember that beautiful isn’t always best – ugly furniture could be better for you.

Sofas with soft curves, squishy seats and dynamic shapes are all the rage, and popular choices for tastemakers are the sumptuous Togo collection of sofas and chairs by Ligne Roset, or the Hem Puffy lounge chair by Faye Toogood.

However, one of the main causes of back pain is furniture that is too spongy or contorts the spine, experts say.

Health and performance coach Luke Hines says “super-soft, ultra cool” couches and chairs are like dessert – indulge in them, but in moderation.

“If you’re lounging once in a while, go ahead and sink in like a cat in a sunbeam,” Hines says. “But if it’s your daily throne, watch out.

“That marshmallowy softness can mess with your posture, making your body work overtime just to stay aligned.

“Balance is key; mix in some structured seating to keep your back happy.”

Fashionable as well as ergonomic is the Goldilocks standard.

“Ergonomic means your body feels supported and aligned without having to overcompensate,” Hines says. “And yes, designer furniture can be ergonomic, but not always.

“Some high-end pieces are all about aesthetics, which I love, but if they leave you feeling like a pretzel after 30 minutes, they’re a no-go.

“The best ones merge style with smart design. Think firm yet comfortable cushions, proper lumbar support, and a shape that encourages good posture.”

Canberra-based physiotherapist and injury prevention expert Ally Reynolds from Your Perfect Posture says the spine’s natural “S” shape must be maintained when seated.

“Sitting with a neutral spine [the S curve] allows our vertebrae, vertebral discs, muscles and ligaments to share loads optimally,” she says.

“Slouching in a C-shape, similar to sitting in a ‘bucket’ chair, forces these structures into compromised positions, potentially causing uneven pressure on discs, overstretching of ligaments, and muscle imbalances that can lead to pain and dysfunction over time.”

Reynolds says watching an hour-long Netflix show on a smooshy sofa can be fine if you don’t have an existing problem, but “for those with back pain, posture issues or other conditions, even brief periods in poorly designed seating can exacerbate symptoms”.

“To be honest, most fashionable seating is designed primarily for aesthetics rather than ergonomic support, but that doesn’t mean they’re inherently problematic,” she says.

“For occasional use, most stylish chairs and sofas are perfectly acceptable.”

Chiropractor Dr Johannes Hofferberth, director of Sydney’s Fika Chiropractic, says his patients commonly have lower-back aches caused by furniture. In extreme cases, that discomfort can extend down the legs.

“Each person is different and at a different stage of life, so furniture needs to suit the individual and what their body needs,” he says.

“Though it must be noted that everyone needs enough support so that their spine doesn’t sag back on itself and promotes a good upright posture.”

Hofferberth says simple additions to support the lumbar (lower back) can improve any style of seating.

“Always having a lumbar roll, pillow or a folded towel behind your lower back goes a long way to help you sit upright without straining your back,” he says.

“It’s important to look at what it’s made out of and how long the product will stay supportive.”

The dimensions of the furniture should be kept in mind on the showroom floor.

This includes a seat height that props knees at a 90-degree angle with feet flat on the floor, and is deep enough to provide thigh support.

Reynolds says five minutes of testing is not enough, so take your time, and don’t sit bolt upright in the store – act naturally and get into your normal position.