Core muscle strength training can reduce the risk of low back pain Original paper

Low back pain (LBP) is the most common musculoskeletal condition in adults, with up to 84% of adults experiencing LBP at some point in their lives.^[1] One potential cause of LBP is weakness in the muscles of the core, including the rectus abdominis, external obliques, and transverse abdominis, which normally stabilize the lumbar region of the spine. Core muscle functional strength training (CMFST), a type of training designed to maintain the stability of the spine during movement by training core muscles, may reduce the risk of LBP. However, no clinical trials have explored this possibility.

In this 12-week, open-label randomized controlled trial, 588 healthy men who underwent basic combat training in a naval training base in China were assigned to either a CMFST group or a control group.

The participants in both groups underwent basic combat training five days per week, while the participants in the intervention group also underwent a CMFST program, which involved performing 3–4 sets per day of four exercises: unilateral hip bridge, quadruped exercise, side bridge, and alternating elbow-to-knee touch.

Core exercises performed in the study

The primary outcome was the total number of LBP incidences in the 12-week study period. The secondary outcomes were low-back muscle endurance, LBP-related pain measured using a visual analogue scale, and LBP-related disability measured with the Roland Morris Disability Questionnaire^[2].

The incidence of LBP in the CMFST group was lower than in the control group (10.8% vs. 20.8%). Similarly, the logistic analysis that adjusted for a number of confounders (including age, education level, BMI, waist-to-hip ratio, and low back muscle endurance) showed that the odds of LBP in the control group were about twice the odds in the CMFST group. Additionally, low back muscle endurance improved more in the CMFST group (+75%) compared to the control group (+26%), as did LBP-related disability (-52% vs. -23%).

One important strength of this trial is that it employed naval recruits, who have highly controlled lifestyles. This means the researchers avoided the complexities that come with studying the effects of specialized exercise in the general population, such as poor compliance with the exercise program, diet, sleep, and other lifestyle choices that may affect the outcomes. However, because the researchers examined a specific core strengthening intervention in healthy naval recruits performing basic combat training, the findings may not be generalizable to other core strengthening programs or to different populations.

Overall, findings from the relevant available research suggest that exercise can be effective for both preventing and treating LBP.

For example, a 2018 meta-analysis of 8 randomized controlled trials found that exercise reduced the risk of LBP by 33%.^[3] However, the meta-analysis did not try to differentiate between the effects of different types of exercise, which were not limited to core strength training, but also involved general strengthening exercises, mixed exercise types, neuromuscular exercise, and yoga.

Fortunately, a 2021 network meta-analysis of 217 randomized controlled trials, summarized previously, involving 20,969 adults with nonspecific low back pain did examine exercise subtypes. According to the findings, all types of exercise, other than flexibility exercise, improved LBP intensity, compared to minimal treatment. The most effective types of exercise were Pilates, McKenzie therapy, functional restoration, and core strengthening exercises.^[4] Moreover, all types of exercise, including core strengthening exercises, improved LBP-related disability. When comparing different types of exercise, core strengthening exercises were more effective for improving LBP intensity and LBP-related disability than several other exercise types, including mixed exercise types and aerobic exercise, which are likely the types of exercise that most resemble basic combat training. However, it’s important to keep in mind that unlike the summarized trial, the trials included in the meta-analysis involved participants with existing low back pain.

Taken together, the findings from the available research suggest that exercise can lower the risk of LBP, and that some types of exercise, including core strengthening exercises, can be more effective than other types of exercise for improving LBP-related outcomes in people with existing LBP. However, other than the trial summarized here, no other trials have specifically examined the effects of CMFST for preventing LBP in people without existing LBP.