Table 1 Eligibility criteria common to all subgroups

1. A primary complaint of either:

a. low back pain, defined as pain between the inferior costal margin and the inferior gluteal fold with or without referral into the leg(s) [138, 139], or

b. referred leg pain, defined as predominately unilateral posterior leg pain extending below the knee, or anterior thigh pain, with or without back pain (disc herniation with associated radiculopathy subgroup only) [56]

2. Duration of current episode of primary complaint lasting between 6 weeks and 6 months (subacute stage of injury [27, 140]), with at least a 4 week pain-free period separating the current episode from any previous episodes [141, 142]

3. Aged between 18 and 65 (inclusive)

4. Fluency in English sufficient to complete questionnaires and to enable understanding of the intervention

5. Classified into one of the five subgroups of low back disorders being targeted in the trial

6. Agreeing to refrain from other interventions wherever possible for the 10-week treatment period of the trial, aside from consultations with medical practitioners, medication, and any exercises already being undertaken

Exclusion criteria

1. An active compensation claim for their back injury, due to the negative influence that this can have on prognosis [125]

2. Active cancer under current treatment, as the treatment of the cancer may interfere with their ability to participate in the trial

3. Signs of cauda equina syndrome based on bladder or bowel disturbance and/or imaging [143]

4. Current pregnancy, or childbirth within the last 6 months, as this could impair ability to undertake exercises, and could also cause back and leg symptoms that are not related to the subgroups under investigation

5. Spinal injections within the last 6 weeks, as we wish to study treatment effects independent to the effects of injections [144]

5. Any history of lumbar spine surgery, as there is already considerable research evaluating the efficacy of post-surgical rehabilitation programs [145]

6. A pain intensity score of less than 2/10 on a 0-10 numerical rating scale due to low severity

7. Minimal activity limitation, evidenced by a baseline ability to walk, sit and stand for one hour or more and no sleep disturbance at night, as we wish to exclude people with low severity

8. Already received more than 5 sessions of physiotherapy with any of the treating physiotherapists prior to enrolment, as these therapists are likely to use many components of the trial treatment protocol on their usual client caseload

9. Inability to walk safely, such as severe foot drop causing regular tripping, as the interventions in the trial include walking for most participants

10. Planned absence of more than one week during the treatment period (such as overseas holidays)