DHAKA: Bending the head at a 60 degree angle to look at a phone screen puts 60 lbs – or 27kg – worth of pressure on the cervical spine, the part of the spine above the shoulders, the study found.

At more than four stone in weight, that is heavier than the average seven year old, reports the Daily Mail.

The extra pressure put on the neck leads to early wear and tear and the person may eventually need surgery, experts said.

Led by Dr Kenneth Hansraj, chief of spine surgery at New York Spine Surgery and Rehabilitation Medicine, researchers found the amount of force on the neck increases with the degree it is bent.

Tilting the head by 45 degree adds the force of 49lbs – or 22kg – to the neck, CBS news reports.

A 30 degree neck tilt equals 40lbs – or 18kg – , while a mere 15 degrees puts an extra 27lbs – 12kg – on the spine.

Writing in the study, the researchers said: 'The weight seen by the spine dramatically increases when flexing the head forward at varying degrees.'

The loss of the 'natural curve' of the cervical spine leads to increased stress on the neck, they added.

They said: 'These stresses may lead to early wear, tear, degeneration and possibly surgeries.'

They concluded: 'While it is nearly impossible to avoid the technologies that cause these issues, individuals should make an effort to look at their phones with a neutral spine and to avoid spending hours each day hunched over.'

The study will be published in the upcoming issue of journal Surgical Technology International.

According to the researchers, bad posture is when the head is tilted forward and the shoulders drop forward in a rounded position.

Good posture was defined as having ears aligned with the shoulders and the shoulder blades retracted.

Previous studies have linked bad posture to a number of health problems, including back pain, weight gain, constipation, heartburn, migraines, and respiratory conditions.

In September, researchers from New Zealand found slouching also has an effect on mental health, making a person depressed, angry, even killing their libido.

Good posture, on the other hand, has been shown to optimise physical and mental health.

Experts advise that sitting up straight allows blood and oxygen to flow freely around the body, and leads to good digestion.

It can also trigger the brain to send out more happiness molecules known as endorphins into the blood, while also reducing the stress hormone cortisol.

BDST: 1111 HRS, NOV 19, 2014