To Flex or Not to Flex?

To Flex or Not to Flex -

Saraceni N et al. To Flex or Not to Flex? Is There a Relationship Between Lumbar Spine Flexion During Lifting and Low Back Pain? A Systematic Review With Meta-Analysis. JOSPT: 2020

  • Workplace safety personnel and healthcare practitioners commonly advise that increased lumbar spine flexion when lifting should be avoided and risk of injury is reduced with a “neutral” spine position.
  • However, implementing this strategy has not resulted in reduced occupational low back pain.
  • While some evidence indicates that high mechanical loads are a risk factor for LBP, those studies have not examined whether lumbar flexion during lifting was a risk factor. Spinal loads when lifting with a flexed spine are in fact similar when compared to a more neutral position.
  • This study aimed to evaluate whether lumbar spine flexion during lifting was a risk factor for LBP onset and persistence, and whether lumbar spine flexion during lifting was different in people with and without low back pain
  • Thirteen papers of 12 studies with 697 participants ultimately met inclusion criteria
  • Four studies measured lumbar flexion w/ intralumbar angles. These studies found no differences in peak lumbar flexion with lifting between groups. These studies were also deemed to be of higher quality evidence b/c they used a method that has been validated against a known gold standard for laboratory motion capture.
  • Seven cross-sectional studies measured lumbar flexion with thoracopelvic angles. People with LBP actually lifted with 6 degrees less lumbar flexion than people without LBP. These studies were also considered to be a lower quality of evidence due to lack of reliability of measurement when compared to a reference standard
  • The authors rated the overall body of evidence in this review as ‘low,” which indicates that the true effect may be substantially different from the estimate of effect.
  • Overall, there was low quality evidence of NO longitudinal relationship between greater lumbar spine flexion during lifting and LBP onset or persistence. Only 2 of 43 comparisons reported greater lumbar flexion in people with LBP.
  • The authors argue that there is no credible in vivo evidence at this time to support the dogma that lumbar spine flexion should be minimized when lifting to prevent LBP onset, persistence, or recurrence.