Table 1 Eligibility Criteria for the SWIFT Trial

Patients with chronic (≥3 months) or recurrent (≥3 episodes in previous 12 months) LBP of mechanical origin with/without radiation to the lower limb

Currently or having received treatment for CLBP within previous 3 months

Males/females between 18–65 years

Red flags indicating serious spinal pathology, e.g. cancer, cauda equina lesion

No spinal surgery within the previous 12 months

Radicular pain indicative of nerve root compression

Patients deemed suitable by their GP/hospital consultant to carry out an exercise programme

Patients diagnosed with severe spinal stenosis, spondylolisthesis, fibromyalgia

Patients willing to attend for an 8-week treatment programme of exercise classes

History of systemic/inflammatory disease, e.g. rheumatoid arthritis

Access to a telephone (for follow-up support)

Patients with any confounding conditions such as a neurological disorder or currently receiving treatment for cancer

Fluency in English (verbal and written)

Patients with acute (< 6 weeks) or subacute LBP (6–12 weeks), provided that they have experienced < 3 LBP episodes during previous 12 months

'Low' or 'moderate' levels of physical activity measured by the IPAQ (< 600 MET-minutes/week)

Unstable angina/uncontrolled cardiac dysrhythmias/severe aortic stenosis/acute systemic infection accompanied by fever

Medico-legal issues

Pregnancy