For as long as we can remember, we have always been told that flexing your lumbar spine during lifting is dangerous and that it can lead to discs “slipping” or “blowing out”  

For as long as we can remember, we have always been told that flexing your lumbar spine during lifting is dangerous and that it can lead to discs “slipping” or “blowing out”. The common advice is to maintain a “neutral” spine, which is a specific position of the spine that is regarded as safe from injury, as seen in Figure 1. Whether this belief is true is still heavily debated, but the important thing to remember is that CONTEXT IS EVERYTHING.  

There is some argument that lumbar flexion, specifically repetitive flexion 1 and long duration stretch under load 2 may pose some risk for injury. A study has found that lifting heavy objects with lumbar flexion led to higher rates of compression on the lumbar spine compared to maintaining a neutral spine.3 However, this train of thought should be questioned, as a study comparing a neutral and flexed lumbar spine found that disc herniation was more prevalent in a neutral spine compared to a flexed one.4 Important to note is that these studies were completed in non-living people, meaning its results may not be applicable to you. This is an important consideration, as discs and any other living tissue of the body can adaptively heal and strengthen over time as the human body is extremely adaptable when exposed to the right stimulus. 

As aforementioned, context is everything when deciding whether lumbar flexion is dangerous when lifting. If you are lifting something that is low load, such as picking clothes off the floor, then it most likely does not matter whether the lumbar spine is flexed or neutral. This is because our spines love movement in any direction and was designed to be flexed. This is demonstrated by a recent systematic review which found that greater lumbar flexion during lifting was in fact NOT a risk factor for developing LBP, nor was it a differentiator of people with and without LBP.5 However, if lumbar flexion is irritating for you modification of how you lift may be warranted initially until your back is desensitised to the movement!  

If you are lifting heavy objects, such as a 20kg bag of cement or even a barbell, the general recommendation would be to lift with more of a neutral spine as there is a slightly higher predisposition of risk of injury with loaded lumbar flexion. However, even if you were to lift with a flexed lumbar spine it does not mean your disc is going to sustain an injury. Regardless of whether you lift with a neutral or flexed lumbar spine, if you progressively load the body and increase its tolerance to load then your risk of injury reduces as the body is extremely adaptable. Anecdotally, there are two types of clients we see who injure their backs from heavy lifting. The first are those who suddenly start lifting heavy objects without prior training/stimulus and have not progressively loaded their back. This may be individuals who have just started a new manual job and have had a period of relative rest or those new in the gym who have started lifting something too heavy too quickly. The second type of clients we see are those that injure their backs from “awkward” lifting techniques due to time constraints and work demands. This awkward technique has little to do with the fact of whether they had a neutral or flexed lumbar spine, but rather they overreached when lifting something heavy or did not have a stable base of support to initiate the lift. To ensure that your back is protected, the team at Elevate Physiotherapy & Pilates are perfectly placed to comprehensively assess risk factors for developing low back pain (LBP) and implement an exercise program to mitigate future episodes of LBP.   

In conclusion, with everyday tasks that involve low load lifting, it does not matter whether a neutral or flexed lumbar spine is maintained, but when lifting something heavy it is recommended to maintain a neutral spine as there is a slightly greater predisposition for injury. Whilst the jury is still not out in terms of whether lifting with a neutral spine is better than a flexed one, the important takeaway from this blog is that progressive loading of the back is the best method to reduce the likelihood of injury with heavy lifting.  

Want a lifting/ergonomic assessment? Call us 9836 1126.   

Written by Mo Bhatnagar (Clinical Myotherapist) 

References

1. 1. Callaghan, J. P., & McGill, S. M. (2001). Intervertebral disc herniation: studies on a porcine model exposed to highly repetitive flexion/extension motion with compressive force. Clinical Biomechanics, 16(1), 28-37. 
   2. Solomonow, M. (2012). Neuromuscular manifestations of viscoelastic tissue degradation following high and low risk repetitive lumbar flexion. Journal of Electromyography and Kinesiology, 22(2), 155-175. 
   3. Wade, K. R., Robertson, P. A., Thambyah, A., & Broom, N. D. (2014). How healthy discs herniate: a biomechanical and microstructural study investigating the combined effects of compression rate and flexion. Spine, 39(13), 1018-1028. 
   4. Veres, S. P., Robertson, P. A., & Broom, N. D. (2010). ISSLS prize winner: how loading rate influences disc failure mechanics: a microstructural assessment of internal disruption. Spine, 35(21), 1897-1908. 
   5. Saraceni, N., Kent, P., Ng, L., Campbell, A., Straker, L., & O’Sullivan, P. (2020). 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. journal of orthopaedic & sports physical therapy, 50(3), 121-130.