... regarding the quality of evidence, and the underpinning relationship betweenaltered behaviour and disability has been called intodoubt by Pincus et al [27]. The restriction of activity by the ‘avoiders’ ... but often only marginally [1,2]. It has been sug-gested that this may, in part, be due to the presence of subgroups of patients that t ogethe r fulfil the inclusioncriteria of the study but ... be predictive of out-comes of care where these are measured by disability,but not by severity of pain , [34-39]. Lower back patientswith high FAB’ s have a poorer response to physicaltreatments...