By: Ryan Hickey, SPT (under direction of Joseph Brence, DPT)
Non-specific low back pain (LBP) has been researched and many have speculated correlations between physical activity and disability. Traditionally, it is assumed that patients who have LBP feel more disabled, report more restrictions within their daily life and as a result, are less physically active. It is important to note that disability and physical activity are not synonymous terms. The ICF states disability is an umbrella term that covers 3 aspects of health: body functions and structures, activity limitations, and participation restrictions. Physical activity is defined as the execution of a task or action by an individual. Simply, disability focuses on what people are unable to do, and physical activity focuses on what people are able to do.
Lin et al recently conducted a systematic review and meta-analysis to assess if a relationship exists between physical activity and disability in acute, sub-acute, and chronic non-specific LBP. Inclusion criteria required disability to be assessed by a self-report questionnaire (eg, Roland Morris Disability Questionnaire, Oswestry Disability Index) and physical activity to be assessed utilizing self reports forms (eg, Baecke Physical Activity Questionnaire, International Physical Activity Questionnaire), or movement instruments such as pedometers or accelerometers. The authors grouped patients into three categories: acute, sub-acute, and chronic. The acuity was based upon duration of LBP: acute (< 6 weeks), sub-acute (6 weeks – 3 months), and chronic (> 3 months).
The final sample size included 2,495 participants’ from eighteen articles that met the inclusion criteria. Seven studies provided data regarding acute or sub-acute LBP, and fourteen studies provided data regarding chronic LBP. The study concluded that there is weak and no significant relation between levels of physical activity and disability for individuals with acute/sub-acute non-specific LBP. However, a moderate and negative correlation exists between physical activity and disability for individuals with chronic LBP. Therefore, as chronicity increases, disability increases, and physical activity decreases. This result indicates individuals with chronic LBP and high levels of disability are likely to have low levels of physical activity.
The inverse relationship between physical activity and disability in individuals with chronic LBP leads to treatment options for this population (eg, enhance physical activity to reduce disability). A compliment to this treatment may be to monitor physical activity outside of treatment by using a pedometer or accelerometer. This adjunct would also allow for patients to visualize feedback and progress accordingly. Individuals who have acute LBP may report various levels of endurance behavior and avoidance resulting in varied levels of physical activity. This agrees with the analysis; lack of association between physical activity and disability for patient with acute LBP. Conversely, chronic LBP patients should avoid the avoidance endurance model which states patient react with avoidance behavior, meaning they will avoid activities because of fear of reinjury. This model approach will result in both a decrease in physical activity and increase in disability.
It is crucial to understand the relationships between physical activity and disability is different across subgroups of LBP. Another study found that the relationship between physical activity and the risk of chronic LBP forms a U-shaped distribution. Therefore, too little and too much activity presented increased risks of chronic LBP. Future research must be conducted to determine whether a low level of physical activity in acute/sub-acute LBP is a prognostic factor for persisting pain. For individuals with chronic LBP, providing interventions to increase their levels of physical activity is justified.
Lin CWC, McAuley JH et al. Relationship between physical activity and disability in low back pain: A systematic review and meta-analysis. Pain 2011: 152;607-613.