The unisex underwear is suitable for nurses, surgeons and anyone whose job entails large amounts of bending that strains the discs.
The smart garment can be turned on by either tapping it or using an app - putting the strain on elastic bands instead of muscles.
It has been likened to the body armour worn by superheroes like the Caped Crusaders, or Iron Man.
Mechanical engineer Professor Karl Zelik, of Vanderbilt University, Nashville, said: "I'm sick of Tony Stark and Bruce Wayne being the only ones with performance-boosting supersuits.
"We, the masses, want our own.
"The difference is that I'm not fighting crime. I'm fighting the odds that I'll strain my back this week trying to lift my 2-year-old."
Half the adult population of the UK report low back pain lasting for at least 24 hours at some time in the year.
The NHS spends more than £1 billion annually treating eight in ten people who will suffer it during their lives.
The researchers said TV infomercials offer a world of potential solutions but most are either unproven, unworkable or just plain unattractive.
So their design combines the science of biomechanics and advances in wearable tech to create a smart, mechanised undergarment.
Prof Zelik began thinking about resolving the problem when he experienced back pain himself from repeatedly lifting his toddler son.
The garment is worn on the chest and legs and consists of two fabric sections made from cheap materials like nylon, Lycra, polyester and other materials.
These are connected by sturdy straps across the middle back, with natural rubber pieces at the lower back.
Experiments showed the clothing offloads stress on the discs.
It is designed so wearers engage it only when they need it. A simple double tap to the shirt works the straps.
When the task is done, another double tap releases the straps so the user can sit down, and the device feels and behaves like normal clothes.
It also can be controlled by an app the team created. Wearers tap their phones to engage the smart clothing wirelessly via Bluetooth.
Eight subjects tested the device leaning forward and lifting 25-pound and 55-pound weights while holding their position at 30, 60 and 90 degrees.
Using motion capture, force plates and electromyography, the team demonstrated the device reduced activity in the lower back muscles by an average of 15 to 45 per cent for each task.
Added Prof Zelik: "The next idea is can we use sensors embedded in the clothing to monitor stress on the low back, and if it gets too high, can we automatically engage this smart clothing?"
Co researcher Dr Aaron Yang, who specialises in non surgical treatment of the back and neck at Vanderbilt University Medical Centre, said the technology is aimed at prevention rather than cure.
It focuses on reducing stress and fatigue on the lower back muscles. He has seen many back belts and braces and typically meets them with scepticism.
Dr Yang said: "People are often trying to capitalise on a huge societal problem with devices that are unproven or unviable.
"This smart clothing concept is different. I see a lot of health care workers or other professionals with jobs that require standing or leaning for long periods.
"Smart clothing may help offload some of those forces and reduce muscle fatigue."
According to the NHS almost 3 million working days a year are lost because of lower back pain.
The underwear was unveiled at the Congress of the International Society of Biomechanics in Brisbane, Australia.