Does leisure time physical activity protect against low back pain? Systematic review and meta-analysis of 36 prospective cohort studies.

BACKGROUND: There are plausible mechanisms whereby leisure time physical activity may protect against low back pain (LBP) but there have been no quality systematic reviews and meta-analyses of the subject.

OBJECTIVE: This review aims to assess the effect of leisure time physical activity on non-specific LBP.

METHODS: Literature searches were conducted in PubMed, Embase, Web of Science, Scopus and Google Scholar databases from their inception through July 2016. Methodological quality of included studies was evaluated. A random-effects meta-analysis was performed, and heterogeneity and publication bias were assessed.

RESULTS: Thirty-six prospective cohort studies (n=158 475 participants) qualified for meta-analyses. Participation in sport or other leisure physical activity reduced the risk of frequent or chronic LBP, but not LBP for > 1 day in the past month or past 6-12 months. Risk of frequent/chronic LBP was 11% lower (adjusted risk ratio (RR)=0.89, CI 0.82 to 0.97, I2 =31%, n=48 520) in moderately/highly active individuals, 14% lower (RR=0.86, CI 0.79 to 0.94, I2 =0%, n=33 032) in moderately active individuals and 16% lower (RR=0.84, CI 0.75 to 0.93, I2 =0%, n=33 032) in highly active individuals in comparison with individuals without regular physical activity. For LBP in the past 1-12 months, adjusted RR was 0.98 (CI 0.93 to 1.03, I2 =50%, n=32 654) for moderate/high level of activity, 0.94 (CI 0.84 to 1.05, I2 =3%, n=8549) for moderate level of activity and 1.06 (CI 0.89 to 1.25, I2 =53%, n=8554) for high level of activity.

CONCLUSIONS: Leisure time physical activity may reduce the risk of chronic LBP by 11%-16%. The finding, however, should be interpreted cautiously due to limitations of the original studies. If this effect size is proven in future research, the public health implications would be substantial.