The authors demonstrate a relationship between physical activity and musculoskeletal (MS) pain noting that “only high physical activity was associated with a lower probability of reporting being troubled by musculoskeletal pain ten years later.” This leads them to propose “increasing physical activity …… should be considered when developing preventative strategies to reduce pain”. However, this makes an assumption about the direction of causality. An alternative hypothesis that would explain this data with the direction of causality reversed is: -
1) Those who suffer some level of MS pain avoid high physical activity
2) Those with no musculoskeletal pain are less likely to have developed material levels of pain ten years later than their peers who were already suffering some MS pain

Accordingly, the findings from this study do not provide unequivocal support for the above proposal.