Sport performance

The Truth About Load Bearing and Lumbar Flexion

by Uperform

We all have to lift more or less heavy objects in our daily lives. Some even incorporate this type of effort into their training. Indeed, load carrying exercises such as the squat or the deadlift are an integral part of the training programs of athletes and the rehabilitation programs of our patients.

At Uperform, we love movement and physical activity prescription. The health benefits of such practices are countless! We are also committed to keeping our patients and the general population properly informed on health matters.

We fight against certain popular beliefs that persist despite scientific discoveries and that are harmful to overall health. The charging port is no exception!

Often decried, is the back as fragile as it is said? Is the charging port a
bad activity for the back? Do you absolutely have to keep your back straight, otherwise you will
hurt ?




Although health professionals and trainers insist on maintaining a neutral lower back position during strengthening exercises, it is actually impossible to keep the back completely straight. This is true even for professional athletes who have complete control over their bodies. Flexion is unavoidable and the amount of flexion in the lumbar spine is only partially changeable.


In this way, we find a use of the lumbar spine in the movements of deadlift, squat and also in explosive exercises where the weight does not touch the ground such as the kettlebell swing. This amount of lumbar flexion does not vary with the difficulty of the exercise. The lumbar spine therefore contributes to strengthening exercises and carrying loads in general and this should not necessarily be seen as a technical error.





The assumption/preconceived idea behind the instruction: “keep your back straight when lifting something!” is that “Lumbar flexion would be dangerous and could lead to injury. Locking down his back and keeping it flat and straight would minimize the pressure put on the osteotendinous structures.” However, this has never been scientifically proven. This lack of evidence in practice means that these claims are ultimately only false beliefs that have managed to infiltrate our daily lives.

A recent systematic review with meta-analysis (this type of review is considered the pinnacle of scientific research) even demonstrates that lumbar flexion is not a risk factor for the onset of low back pain.




After having fully established the fact that lumbar flexion when carrying a load is inevitable, one comes to wonder if the body does not purposely adopt this position unconsciously to have more strength and power. The best powerlifters/weightlifters use a large amount of lumbar flexion during competitions.


In fact, in the position of lumbar and thoracic flexion, it is possible to bring the weight lifted closer to the body and thus reduce the lever arm. Another explanation for the benefit of lumbar flexion in lifting heavier weights comes from the moment of force of the hip muscles.

Indeed, the more you flex your hips, the more difficult it is for the gluteus maximus and hamstring muscles (the main hip extensors) to exercise their full potential. Their
functioning is therefore optimal when the amount of flexion is shared between the back and the


In conclusion: lumbar flexion, which is inevitable anyway, is not problematic and allows
even a performance boost in the charging port. This is an effective movement strategy
used by our body. There are still many prejudices about the broad problem of low back pain and it has been commonly accepted that lumbar flexion is the main one.


It is high time to change our treatment approaches and the way we think about back movement. Everyone is different and each low back pain is treated differently. If you suffer from low back pain or if you want to start muscle building but don’t know where to start, contact a member of our team who will follow you according to your abilities and needs.



We care, you perform.




Bibliographie :
Howe L et Lehman G. Getting out of neutral: the risks and rewards of lumbar spine flexion during
lifting exercises. Article in Strength and Conditioning March 2021.