Disclaimer: I am not a physician or exercise scientist.
Low back pain (LBP) is an extremely common and debilitating symptom worldwide, experienced by people of all ages and socioeconomic circumstance [1]. In 2017, LBP contributed 65 million disability-adjusted life-years and was the primary cause of work absenteeism and disability worldwide [2]. Most LBP cannot be attributed to a specific source and bouts, while typically short, frequently reoccur [1].
Clinical practise guidelines consistently recommend against treating LBP with opioids, foot orthotics, disc replacement and spinal injections [3]. In particular, opioid use is discouraged for LBP due to the potential for opioid-related harms and the recent finding that NSAIDS are equally efficacious for treating acute LBP [3]. Similarly, routine medical imaging for non-specific LBP is associated with harms [3]. Despite the consistency of these guidelines, imaging, surgery and opioids are overused in clinical practise [3].
The most effective preventative treatment for LBP seems to be exercise, with or without accompanying education [4]. Exercise alone reduces the risk of LBP by 33% on average, with a 95% confidence interval of 15-47% risk reduction [5]. Further research into optimal frequency, intensity, type and duration of exercise for the prevention and treatment of low back pain is recommended [4]. As a naive starting point, the Physical Activity Guidelines for Americans recommend that all adults perform resistance exercises of moderate or greater intensity for all major muscle groups at least twice per week, in addition to minimum aerobic activity guidelines [6]; the Physical activity and exercise guidelines for all Australians concur [7].
While no specific form of sufficiently intense full-body resistance exercise is recommended above all others, I have highly enjoyed resistance training with free weights; I find the capacity for consistent and graded progress very rewarding, and there is a wealth of associated high-quality educational resources. I highly recommend Barbell Medicine's free exercise program and their article on understanding and training around pain. Individuals who are unable to perform basic barbell movements through a full range of motion can instead use light dumbbells or even decrease the range of motion if necessary.
Individuals new to resistance training might experience the following barriers:
- Insufficient time or money to engage in gym-based activity. Gyms typically cost $12-15/week in Australia. Resistance training in a gym should not require more than 60-90 minutes per session. Barbell Medicine also provide a free at-home exercise program. Prioritising self-care can be difficult and, ultimately, any training is better than no training.
- A lack of training motivation. Self-monitoring and goal-setting behaviour, such as recording progress and setting achievable targets, can significantly improve exercise motivation [8]. Group exercise, such as with a friend or personal trainer, can also significantly improve motivation and enjoyment [8].
- Fear of injury or preoccupation with perfect form and 'mobility'. There is no evidence that lower back flexion during resistance training is a risk factor for LBP onset or persistence [9]. People with LBP tend to move with a more rigid back than those without pain [10], potentially a learned response to a misplaced narrative about the dangers of spinal flexion. Movement variability is safe and normal, and one should expect lower back flexion during resistance exercise. Improving 'mobility' should not be prioritised over resistance training.
It's not clear to me that Huang et al. compared exercise to the best alternative interventions, so it seems safer to say that it's best among those included in that review, and perhaps among the interventions that have been studied the most. But that's a considerably weaker claim than "low back pain is best prevented by exercise".
[ETA: Also, are you sure that stretching wasn't in many cases part of the exercise studies included in the review? It's not clear to me from reading the paper, and if it was included, the review might actually support stretching, too, as opposed to supporting exercise over stretching. In any case, it's not clear to me that the claim about exercise being more important than stretching is in fact supported by the review in question.]
FWIW, the data I've seen on the effects of getting a better bed, both in terms of small-scale studies and anecdotal evidence, suggests that it could well be more significant, and at least that it's more significant for a considerable number of people (probably especially among those who are already quite physically active). (Note also that it might be expensive and difficult to find appropriate beds for a large number of people in a study, which could be a hurdle to proper studies of this intervention.) I also wouldn't be surprised if curcumin supplementation did significantly better than the best exercise interventions if compared head-to-head (it's probably the single most effective thing I've tried, and I'd strongly encourage people with LBP to try it).