“Don’t round your back”, “Lift with your knees, not your back”, and “keep you back straight” are among the most commonly used phrases for “injury prevention.” When looking at the research, these phrases fail to hold water.
Lifting with a rounded low back is not asking for a back injury. A recent study reviewed over 4500 articles to determine what the current body of research has to say about lifting with a rounded low back. Here is what they concluded:
“There was no prospective association between lumbar spine flexion when lifting and the development of significantly disabling low back pain. There was no difference in peak lumbar flexion during lifting between people with and without LBP. Current advice to avoid lumbar flexion during lifting to reduce low back pain risk is not evidence based.”
Translation: lifting with a rounded low back does not cause or maintain low back pain.
Still not convinced? Let’s break it down.
Your Spine Is Stable
The early studies that claim rounded — or flexed — spines are dangerous were conducted using dead human and animal models. This is a problem as living models are significantly different. Our bodies are not strictly mechanical and they are highly adaptive. Furthermore, just because something causes more force does not mean the force is dangerous.
Let’s take it one step further. In some cases, a rounded low back can be advantageous.
Some studies show the spine is in a more stable position when flexed. Flexing the back shortens the distance you have to bend your hips and knees to improve the length-tension relationship allowing you to produce more power. Essentially, rounding your back can allow you to use physics in your favor.
Studies assessing ergonomics show “proper” lifting techniques may cause more shear stress in the spine than rounding the back. Again, the force is not great enough to be injury-inducing.
It Is Impossible to Keep Your Back Straight
Ok, let’s say you are still determined to keep your back straight. In your experience, a straight back simply feels better. No matter how straight your back looks in the mirror, the spine is still flexed.
Coached to keep the low back ‘neutral’ during deadlifts: an average of 22 degrees of flexion
Coached to keep the low back ‘neutral’ during kettlebell swings: an average of 26 degrees of flexion
Coached to ‘brace as hard as possible’ during good mornings: 25-28 degrees of flexion
Strongman athletes competing (picking up really heavy things): up to 45 degrees of flexion
Your spine will not crumble if you lift heavy objects in a ‘non-neutral’ position — however you define that — but does that mean injuries won’t occur? What happens if you repeatedly lift with a rounded low back?
Injuries Are Complex
The study I opened the article with limited the lifting to 25 pounds. What happens if you lift more weight repeatedly, such as warehouse workers or movers need to do? What about carrying awkwardly shaped objects in various positions (twisted, not just rounded)?
Workplace ergonomics training focused on reducing lumbar flexion does not work. It is not worth the time or effort to teach people to keep their backs straight. Pain and injuries are multi-factorial and focusing on a single cause is rarely the answer.
Looking at work-related pain specifically, low job satisfaction, poor exercise tolerance, inactivity, and health issues are greater concerns than lifting technique. When looking at injuries in general, overload and poor recovery are the primary culprits.
This does not mean repeatedly maxing out deadlifts with a round back won’t lead to an injury, but the injury is more likely the result of excessive demand placed on the entire body, not just the spine (deadlifts are very demanding). Instead of focusing on lifting techniques, focus on overall health and exercise. Research shows exercise is one of the most effective treatments for back pain at work.
At the end of the day, our backs are strong and stable. Our bodies adapt to the demands put on them. You may experience pain when lifting with a rounded back and I encourage you to look at the big picture. The issue is rarely the fact that the back is rounded with lifting, it is instead the volume of work and lack of rest.