SCOTS workers are putting their mental and physical health at risk by working almost two hours extra at home on laptops and smartphones every night, new research has claimed.

The intensive use of portable technology is creating thousands of "screen slaves" who are susceptible to musculoskeletal disorders and stress, the Chartered Society of Physiotherapists (CSP) said.

Nearly two-thirds (64%) of office workers polled in Scotland for the CSP said they continued working on smartphones and other devices after they left the office and spent an average of one hour and 56 minutes on out-of-hours tasks.

This comes in addition to the average five hours and 53 minutes in front of a computer screen on a regular working day.

Kirstin Lord, of the Physiotherapy Centre in Glasgow and Edinburgh, said the vast majority of patients seeking treatment were suffering from conditions linked to the workplace.

Ms Lord said: "People are sit-ting down for long, long periods of time at work to use a computer and when they get home they will be using their smartphones for emails or to flick on to Facebook. People are spending a lot of time based on a computer, and it is putting the same sort of sedentary pressure on the body all of the time.

"People don't think about the time they are spending in the home environment as work, but the reality is you are doing something that is very abnormal to the body. We are not designed to do this stuff, we are designed to move."

Ms Lord said common problems linked to work station use were stiffer and tighter joints plus back, neck and shoulder pain. Jaw clenching and migraines were common among those suffering from stress, she added.

She said: "A lot of people tend to poke their chin out when using a computer, but that can squash the vertebrae and compress the blood flow into the brain.

"If you are tight and stiff in the upper part of your body it is far easier to damage yourself. Even if you have a sporting injury, it is usually because of a build-up of tension in the body."

The research found that 53% of office workers had seen their out-of-hours working increase in the past two years.

Of those asked, 39% said they did the extra work "to ease the pressure of the working day" and "to get ahead of myself" (29%).

Just under one-third (30%) said additional work at home helped reduce their overall stress levels.

Martin Haggarty, of small motor insurance claims business Accident Claims Scotland in Hillington, Glasgow, said it was usual to deal with work-related communications via his smartphone from around 7am to 10pm.

He said: "Mostly, I manage to keep work life separate from outside life but sometimes it is impossible. A lot of my clients are based down south so you have a lot of people travelling on early flights and late flights. When you are sitting on a train or a plane now, you are basically working. With the smartphones, you are very conscious of the fact of emails pinging in. You tend to deal with them there and then.

"If you were to work in the old-fashioned way, however, you would be staying in the office until 6.30pm or later, and I think that is far more intrusive into your own life. The technology allows you to be flexible so there is a positive side too." Today around 300 physiotherapists will be sent into workplaces across the country to encourage staff to be more physically active on Workout at Work Day. The CSP said companies should forge links with gyms and active travel schemes, with staff encouraged to take regular breaks and be physically active.