Don’t Bend and Lift after Sitting for Hours

What happens to the lumbar spine after several hours of sitting at a desk? Is the low back at risk for injury from prolonged sitting? Do women respond differently to long periods of sitting compared with men? These are all questions answered in this study from
the University of Waterloo in Canada.

Six men and six women with no prior back pain or problems were part of this study. All were university students who sat on an office chair doing deskwork for two hours. Lumbar range of motion was measured before sitting, after one hour of sitting, and after two hours of sitting.

The researchers found men and women respond differently to long periods of sitting. Men had more low back stiffness after one hour of sitting compared to women. Low back stiffness varied among the women over the two-hour trial. Men seemed to reverse the stiffness by sitting up straighter during the second hour.

The authors suggested the following ideas from their results:

  • Differences between men and women have more to do with the way people sit than to any biologic differences in the way the muscles contract.
  • Long periods of sitting may lead to low back pain because people can’t always change
    their posture, the task, or the workstation.

  • Spinal ligaments and discs are subjected to stress after prolonged sitting; therefore, stooped lifting should be avoided after long periods of sitting.
  • Work-rest schedules should be varied for workers who sit for hours at a time; job rotation may be another way to reduce injury after long periods of sitting.