Backpacks and the Lumbar Spine – The truth revealed

boy-wearing-backpack-0-280x280shell-garden-path

It has long been assumed that backpacks are better than over the shoulder bags for preventing lower back and neck pain. I tell my patients on a day-to-day basis that although the humble backpack may not be the most fashionable item to carry, it will save your back in the long run. My days of imparting this information to patients is over, and I am truly sorry to those (especially the children) to whom I have led up the garden path.

A recent article in Spine (2010) titled The Effect of Backpacks on the Lumbar Spine in Children: A Standing Magnetic Resonance Imaging Study.

The study abstract is seen below.

Study Design: This study is a repeated measures design to measure the lumbar spine response to typical school backpack loads in healthy children. The lumbar spine in this setting was measured for the first time by an upright magnetic resonance imaging (MRI) scanner.
Objective: The purpose of this study is to measure the lumbar spine response to typical school backpack loads in healthy children. We hypothesize that backpack loads significantly increase disc compression and lumbar curvature.
Summary of Background Data: Children commonly carry school backpacks of 10% to 22% bodyweight. Despite growing concern among parents about safety, there are no imaging studies which describe the effect of backpack loads on the spine in children.
Methods: Three boys and 5 girls, age 11 ± 2 years (mean ± SD) underwent T2 weighted sagittal and coronal MRI scans of the lumbar spine while standing. Scans were repeated with 4, 8, and 12 kg backpack loads, which represented approximately 10%, 20%, and 30% body weight for our sample. Main outcome measures were disc compression, defined as post- minus preloading disc height, and lumbar asymmetry, defined as the coronal Cobb angle between the superior endplates of S1 and L1.
Results: Increasing backpack loads significantly compressed lumbar disc heights measured in the midline sagittal plane (P < 0.05, repeated-measures analysis of variance [ANOVA]). Lumbar asymmetry was: 2.23° ± 1.07° standing, 5.46° ± 2.50° with 4 kg, 9.18° ± 2.25° with 8 kg, and 5.68° ± 1.76° with 12 kg (mean ± SE). Backpack loads significantly increased lumbar asymmetry (P < 0.03, one-way ANOVA). Four of the 8 subjects had Cobb angles greater than 10° during 8-kg backpack loads. Using a visual-analogue scale to rate their pain (0-no pain, 10-worst pain imaginable), subjects reported significant increases in back pain associated with backpack loads of 4, 8, and 12 kg (P < 0.001, 1-way ANOVA).
Conclusion: Backpack loads are responsible for a significant amount of back pain in children, which in part, may be due to changes in lumbar disc height or curvature. This is the first upright MRI study to document reduced disc height and greater lumbar asymmetry for common backpack loads in children.
Approximately 90% of children in the USA wear backpacks loaded with 10-22% of their body weight, as replicated in this study (Watson et al, 2002). Thirty-seven percent of children aged 11 to 14 years report back pain, that they attribute to wearing a backpack. (Skaggs et al 2006).

An interesting study by MacKenzie et al (2003) “summarized the following as risk factors for low back pain in schoolchildren: female gender, poorer general health, high levels of physical activity (including sports competition), time spent sitting, heavier backpack loads, greater time spent carrying a backpack, low physiologic maximum lumbar spine mobility, and a family history of back pain.”

From this point in time, I’ll be telling my patients to wherever possible transport heavy loads in a bag with wheels.

  • Share/Bookmark
Published on Apr 10, 2010
Author: Benjamin Gold
4 Comments

Facebook comments:

Comments

Ben,

What a great post. Living in NY, it seems that everyone is carrying a bag of some sort. I cringe when I see kids who weigh 100lbs soaking wet carrying a bookbag that is probably half their body weight. I actually like to wear my bookbag on the front of my body to train the posterior chain of muscles. Keep up the good work!

posted by Christopher Johnson on 04.12.10 at 11:01 am

Thanks Chris,
I didn’t even think of telling patients to put the pack on their front. What a great idea for training posterior muscles!

posted by Ben Gold on 04.14.10 at 7:43 pm

Hello, your post would make for real great reading. there is not adequate blogs outthere that will have outstanding reading material, large thumbs up from me and i’ll be hanging around quite a bit in the future.

posted by Penney Grover on 04.23.10 at 12:37 am

Thanks for the thumbs up Penney. Appreciate your support

posted by Ben Gold on 05.05.10 at 12:45 pm

Leave a comment

  • Current News

  • Recent Comments

  • Contributor Blogs

  • Write For Us

    If you want to write for us just drop us a line. We will respond as soon as possible.


    jon@theptproject.com

  • Follow Us