Nfld. & Labrador

Oh, the pain of it: Researchers at MUN hope to find out if sitting is bad for the back

A study is underway at Memorial University in St. John's that could make things easier on your back. And wouldn't that be great?

Study could determine guidelines for how long is too long to be sitting

A Memorial University study is hoping to help improve the way we live with our backs. (Glenn Payette/CBC)

A study is underway at Memorial University in St. John's that could make things easier on your back. And wouldn't that be great?

A team of researchers is looking at how sitting too long can affect how the back works. Specifically, they are trying to find out if sitting too long stops the muscles in the back from working they way they should, which can lead to injury. 

"We weren't designed to sit for long periods of time," said Dr. Diana De Carvalho of MUN's School of Medicine.

"This is basic science research that is going to give us more, a better understanding of how the back works, how injuries might happen.

Dr. Diana De Carvalho hopes the study will determine how long is too long for our backs when it comes to sitting. (Glenn Payette/CBC )

"And if we can understand that, we can do a better job of preventing injuries in the first place [and] coming up with better guideline on how long someone should sit."

It's the "how long someone should sit" that is at the heart of this study.

"We're interested in understanding more about how back injuries happen. The mechanism of injury," said De Carvalho.

"What we have going on is a study that is looking at whether or not sitting for long periods of time, in this case, two hours, if that changes how the muscles turn on and function normally in the back."

A screen shows a couple of muscles firing in the lower back. (Glenn Payette/CBC )

To get that information, they strap a subject into a harness, attach electrodes to six muscles in the lower back and  monitor the spine angle.

The harness is attached to a cable that is released without warning, causing the subject to fall slightly forward until the back muscles kick in to stop the fall. 

The electrodes send information to a monitoring system to measure how each of the six back muscles have responded. The muscles should fire automatically in a normal reflex reaction.

When the subject isn't expecting it, a cable attached to a harness is released to test how the muscles in the lower back are working. (Glenn Payette/CBC)

"The reflexes are the way muscles turn on without you even thinking about them. It's the way our body protects itself." said De Carvalho.

After what's called "the drop," an initial reading is taken, the subject then sits at a normal looking work station for two hours and notes any pain they are having.

After the two hours, the subject is put back in the harness, and the drop is repeated again to see if the muscles fire the way they should to protect the back.  

Kinesiology study Sarah Mackey is one of the subjects taking part in the study, and has sat for two two-hour stretches as part of the research. (Glenn Payette/CBC)

"Most people are sitting for most of their work day," said De Carvalho. "And the question is, does sitting for a long period of time change how our back would normally function, and maybe make us more at risk for hurting ourselves, say, if we pick up a pencil off the floor after we've been sitting in the office all day."

Kinesiology student Sarah Mackey has been the subject for two sessions in the study, which is her work-term assignment.

Mackey said the drop didn't hurt, but sitting for two hours wasn't fun.

The study is part of Ryan Greene's master's thesis. (Glenn Payette/CBC)

"The whole time you want to get up, and when you stand up, it's a relief. It's definitely a relief," said Mackey. She hasn't hurt her back — "Not yet," she added.

The study is part of Ryan Greene's thesis for his master of science degree. 

He said the information they find isn't just for those who sit at desks. 

"This might also apply to other professions, such as truck driver, pilots, things like that … professions which involve prolonged sitting."

They hope to have the data collected by the end of July, with the results of their research, and some practical advice, ready to present at a conference of the Canadian Society of Biomechanics this August in Halifax.

About the Author

Glenn Payette


A veteran journalist with more than 30 years' experience, Glenn Payette is a videojournalist with CBC News in St. John's.