The number of Kiwis suffering from severe neck or upper back pain is increasing as people spend more time hunched over phones, tablets and laptops, experts say.
And the number of school children needing treatment has also risen.
Retired New Zealand physiotherapist Steve August has dubbed it the iHunch.
He believed the amount of time people spent slouched over portable electronic devices was causing more people to seek treatment for upper back and neck pain.
"We've a generation of computer-savvy New Zealanders coming through with levels of upper back and neck pain like we've never seen before. The driver is the ubiquitous use of laptops, tablets and smartphones," he said.
"These are not like desk computers - you cannot separate their screens from their keyboards (without losing their portability). So you have to hunch to use them, and everybody's using them, and it's the hunching that drives most neck pain."
August, who worked as a physiotherapist for more than 30 years, said he used to see dowagers' humps, where the upper back was locked in a curve forward, in grandmothers and great-grandmothers but now was noticing teenagers with the same stoop.
He said, based on conversations with specialists and patients, the number of people with upper back or neck pain was increasing "like a skyrocket".
Based on a series of studies, he estimated about one in six people were feeling severe pain in those areas at any one time.
"It's a tsunami. I'm not overstating it at all," he said. "We have never had this before."
A Finnish study found two hours or more of computer use each day was associated with a moderate to severe increase in musculoskeletal pain while another study found one in six Kiwi 15-year-olds were on the internet for more than six hours a day.
Last year ACC received claims for 141,093 neck, back of head vertebrae and upper back soft tissue injuries - up from 130,771 in 2014, although the most common cause was a fall.
Dr Cassandra Fairest of the New Zealand Chiropractors' Association said she too had noticed an increasing number of patients with neck and upper back pain and agreed the increasing use of handheld technology was a major cause.
"We can look at today's lifestyle and see what's changed - and technology has," she said.
Fairest said she was treating more and more people with anterior head carriage - when the head is positioned in front of the body, and was even seeing school children with the condition.
"It's from prolonged use of handheld devices. If you watch people that use them, their head is almost at a 90 degree angle," she said.
The average adults head weight between four and five kilograms and was designed to sit balanced on the top of your spine, Fairest explained. "The more that your head goes forward, you start to get neck strain because it has to support the weight of your head."
The problem used to be largely isolated to people who worked on computers all day but it had now spread beyond that to anyone who used a hand-held device, she said.
"It's going to get more and more and more common as technology progresses," she said.
Specialist anaesthetist and pain consultant in Dunedin, Dr Charlotte Hill, confirmed there was an increase in people suffering from neck and back pain internationally which was being seen in pain clinics in New Zealand.
The Global Burden of Disease Study, which tracks the prevalence of disease and death worldwide, found that the amount of disability associated with back and neck pain globally had increased 17 per cent between 2005 and 2015. That meant the disability from neck and back pain was worse than that from diabetes, all cancers, strokes, Alzheimer's, HIV/AIDS and road injuries, she said.
She said there was no research to show why neck and back pain were becoming more common but said one theory, which was anecdotally observed by some physiotherapists, was that spending a long time sitting with a poor posture, such as when using a hand-held electronic device, was contributing.
Physiotherapy New Zealand research and learning advisor Nick Clode said there had been little research into the impacts of handheld devices on the body. "It's probably something we need to look at developing research into."
Auckland University of Technology associate dean of health Duncan Reid said he could not definitively say handheld devices caused neck pain but said there were an increasing number of people presenting in discomfort from sedentary type activities.