These data suggest that the activity levels of patients with NSLBP are neither associated with , nor predictive of , disability or pain levels .
Although clinical guidelines advocate exercise and activity in the management of non-specific low back pain ( NSLBP ) , the link between levels of physical activity and outcomes is unclear .
This systematic review investigated the relationships between free living activity levels  after onset of low back pain ( LBP ) and measures of pain , and disability in patients with NSLBP .
Hierarchy of evidence: where observational studies fit in and why we need them.
Although r and omized controlled design s are considered the so-called gold st and ard in medical trials and sit atop the hierarchy of evidence in evidence -based medicine , there are situations in which they are impractical or unethical to undertake , especially in surgical trials . Then , observational studies often provide the best source of information . In this paper , we use examples from the literature to explain the importance of observational studies in furthering the boundaries of orthopaedic surgery and knowledge of musculoskeletal disorders
These data suggest that the activity levels of patients with NSLBP are neither associated with , nor predictive of , disability or pain levels .
Although clinical guidelines advocate exercise and activity in the management of non-specific low back pain ( NSLBP ) , the link between levels of physical activity and outcomes is unclear .
This systematic review investigated the relationships between free living activity levels  after onset of low back pain ( LBP ) and measures of pain , and disability in patients with NSLBP .