Sept. 5 2024

Many are told not to “round their backs” or not to “lift too heavy” to prevent injury or pain, but where did this advice come from, and is it actually true?

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Low back pain (LBP) is ubiquitous in our society, with 39% of US adults reporting back pain in the last 3 months, according to data collected by the CDC in 2019. With such a high incidence of LBP, many wonder what the causes are. Is it a specific movement, load or occupation that carries the most significant weight in causing LBP? It is undoubtedly multifactorial and not caused by a single factor, right?

Yet, many employers, fitness and health professionals have told most people to “protect the low back,” not to flex or round the back or lift too heavy. This advice likely comes from many places, most likely older biomechanics research where pig spines were tested, not live human spines. Many of these older biomechanics studies showed greater forces in the spine and discs, but they tested on dead pig spines in a manner that would be unrealistic for a live human spine.

This advice is further reinforced in the workplace with lifting safety messaging such as this:

To add further kinesiophobia to the general public, some health professionals describe the intervertebral discs as “jelly donuts.” Who would want to risk jelly rupturing out of their donut when lifting? The effectiveness of mobilizing the public to exercise more with this imagery is questionable.

Even Google’s AI Overview states that, “Lifting something heavy can cause lower back pain by straining muscles or spraining ligaments. This is because the force of lifting can be jarring if you don't use proper technique.” Instead, it recommends lifting by bending the knees without bending forward — in other words, don’t deadlift.

Let’s examine the effects of spine position and load on LBP using up-to-date research.

The Public’s Perspective on Exercises for

Low Back Pain

The public often shares similar ideas on which exercises are good versus bad for low back pain. Typically, people think specific trunk or core stability exercises are best for improving low back pain, and general strength exercises are unsafe. However, recent research has shown that particular types of exercises, specifically core exercises like bird dogs and planks, do not result in better outcomes than general exercises, even powerlifting exercises.

A recent study surveyed 113 participants using a six-point Likert scale to categorize people's beliefs about individual exercises' effect on low back pain. Open-ended questions were also used to gather further beliefs.

The specific exercises in question were:
● Bird dogs
● Curl ups
● Side planks and regular planks
● Dead bugs

The general exercises in question were:
● Romanian deadlift
● Zercher squat
● Jefferson curl
● Good morning
● Bulgarian split squat

The survey showed that people believe the following about exercise characteristics for those with low back pain:
● Exercises should “target the core”
● Exercise should strengthen the glutes, lower back and abs
● Exercises that load “too much” are the cause of pain and should be avoided
● Exercises should improve the stability of the hips and spine
● Exercises shouldn’t flex the back

The researchers concluded that individuals with chronic low back pain tend to find specific exercises more effective than general ones. As fitness professionals, we must understand that the exercises we give our clients have an implicit meaning and intent, even if we don’t explicitly say so, because people attach beliefs to exercises they’ve heard or experienced.

This said, we must be sure to ask ourselves why we are picking a specific exercise, not just because we read in a book or heard at a conference that it is for a specific reason. It is more about why we’re giving an exercise than what exercise it is. The messaging we deliver, verbally and through exercise prescription, implicitly communicates to the client.

Spine Position’s Effect on Low Back Pain

A review of twelve articles investigated the relationship between lumbar spine flexion during lifting and low back pain (Sarecini, 2020, to flex or not to). Two interesting findings were that lifting with a flexed spine was not a risk factor in low back pain, and people with LBP had reduced lumbar flexion of 6% compared to those without LBP. They concluded that telling people not to round their backs was unjustified and created fear of movement.

This research shows that those with no LBP use more lumbar flexion when lifting than those with LBP. This means that lumbar flexion is not correlated with causing back pain. However, for those with LBP, lumbar flexion exacerbates it, which is why they lift with less lumbar flexion.

Older research suggests that twisting or rotating the spine is a risk factor for the onset of LBP, but newer research indicates conflicting evidence.

Load’s Effect on Low Back Pain

A review of 22 studies on load (the amount of weight lifted) and low back pain found insufficient evidence to support a causal relationship between loading and the onset and persistence of LBP. The studies reviewed could not provide a biological explanation for this relationship. Interestingly, the studies also showed that lowering load did not lower pain levels in those with LBP.

Another review examined studies that used deadlifts as a rehabilitative exercise for those with LBP. It found that exercise programs that include deadlifts can improve pain and function for those with LBP but were not more beneficial than low-load exercises. The review suggests those with lower pain levels and higher baseline lumbar extension strength may be most appropriate to participate in an exercise program that includes deadlifts.

A randomized control trial compared low-load and high-load 12-week exercise programs on 70 individuals with low back pain. The low-load program found better activity, movement control and muscle endurance results but not in pain and strength.

The conclusions of all three studies show that a spectrum of loads may improve outcomes in LBP, supporting the efficacy of high loads in a training program for those with LBP.

Specific Activities’ Effect on Low Back Pain

A systematic review of 86 studies aimed to determine the prevalence of LBP in sport and what risk factors were associated with LBP in athletes. They found that current evidence cannot identify which sports are at the highest risk for LBP. Common risk factors for LBP are more apparent. A previous episode of LBP, high-training volume, periods of load increase and years of exposure are common risk factors.

These findings appear to suggest that LBP is caused less by a specific activity and more by an individual's prevalent risk factors. This means that LBP incidence may be managed by monitoring training volume and planning load increases at times of low overall stress on the body.

Other systematic review studies conclude that it is difficult to identify one particular activity as the cause of LBP.

Training Volume’s Effect on Low Back Pain

So far, this article has covered the effect of spinal position, load lifted and specific activities on LBP with little to no evidence that they contribute to or cause it. Training volume, however, is a variable that is not considered as much for some reason, yet it is essential to consider when programming an exercise routine.

Research reviews have found a correlation between training volume (from low to high loads) and LBP. This is explained by the acute workload exceeding the chronic threshold tolerated. Each individual’s acute workload tolerance changes daily with healthy, competitive schedules, stress and activity levels. In other words, the body needs time to recover from training and cumulative life factors.

One tool that has been hypothesized similar to this idea is the acute: chronic workload ratio (ACWR). This index of the acute workload is relative to the cumulative chronic workloads. This tool can be used to optimize performance while aiming to reduce the risk of potentially preventable load-driven injuries.

A bird' s-eye view of the formula for the ACWR is workload from the last 7 days divided by the average workload from the last 28 days.

What We Learned

In this article, we investigated several variables that factor into LBP, such as the spine’s position, load lifted in a single bout, specific activities and overall training volume. All of those variables except overall training volume have little effect on LBP. This means that rather than restricting certain spine positions, loads or activities, it may be better to consider the overall volume of work (in specific positions, loads and activities) when managing and preventing LBP. LBP is highly individual and multifactorial, so due diligence must be done to understand each individual’s situation and modify training appropriately. Furthermore, due to these findings, we as fitness professionals must consider the messaging we give our clients around exercise and low back pain because they may have strong beliefs about specific exercise characteristics and associate beliefs with the exercise and our reasoning for it.

Brandon Hyatt, MS, CSCS, NFPT-CPT, NASM-CES, BRM, PPSC is an experienced leader, educator, and personal trainer with over 7 years of success in building high-performing fitness teams, facilities and clients. He aspires to become a kinesiology professor while continuing to grow as a professional fitness writer and inspiring speaker, sharing his expertise and passion. He has a master's degree in kinesiology from Point Loma Nazarene University. His mission is to impact countless people by empowering and leading them in their fitness journey.