Table 1 Characteristics of included studies

Inclusion criteria

Age 18-65 years. Low back pain (LBP) of less than 90 days with or without referral into the lower extremity, and an Oswestry disability score ≥ 25%.

Age 18-60 years. Primary symptom of LBP, with or without referral into the lower extremity, Oswestry disability score of at least 30%.

LBP of < 6 weeks duration, causing moderate pain and moderate disability (measured by adaptations of items 7 and 8 of the SF-36)

Age 18-65 years. LBP with or without leg symptoms and with or without a neurological sign. Demonstrating a directional preference.

Exclusion criteria

A visible lateral shift or acute kyphotic deformity, signs of nerve root compression, red flags indicating a serious pathology, an inability to reproduce any symptoms with lumbar spine active range of motion (AROM) or palpation, pregnancy, prior surgery to the lumbar and/or sacral region.

Patients with red flags for a serious spinal condition, signs consistent with nerve root compression, pregnancy, prior surgery to the lumbar spine or buttock.

Current episode not preceded by a pain-free period of at least one month in which no care was provided, known or suspected serious spinal pathology, nerve root compromise, currently receiving non-steroidal anti-inflammatory drugs or spinal manipulative therapy, surgery within the preceding 6 months, contraindication to paracetamol, diclofenac or spinal manipulative therapy.

Cauda equina syndrome. Two or more neurological signs. Spinal fractures. Post-surgical. Off work for one year or more due to LBP. Medical causes (for example, severe osteoporosis, inflammatory or infectious conditions). Uncontrolled medical conditions (for example, diabetes, angina, hypertension). Pregnancy. Inability to read English. Patients with prior knowledge of, or specific physician referral for, the McKenzie method. No directional preference.

Clinical prediction rule

Delitto Treatment Based Classification

Flynn manipulation prediction rule

Flynn manipulation prediction rule

McKenzie directional preference-based exercise

Targeted treatment

Mobilization (low amplitude), manipulation (thrust), exercise (AROM, McKenzie or strengthening and stabilization) n = 50

Manipulation (thrust), Exercise (ROM) n = 70

Mobilization (mostly low velocity spinal mobilization, but 5% received manipulation) n = 114

Exercise (McKenzie directional preference exercises) n = 70

Non-targeted treatment

Mobilization (low amplitude), manipulation (thrust), exercise (AROM, McKenzie or strengthening and stabilization) n = 73

Exercise (stabilization, low-stress aerobic, strengthening) n = 61

Sham mobilization (detuned ultrasound) n = 121

Exercise (exercises opposite to directional preference or non-directional exercises) n = 131

Outcomes

Oswestry Disability Index

Oswestry Disability Index

Roland Morris Disability Questionnaire, Pain Numerical Rating Scale

Roland Morris Disability Questionnaire, Pain Visual Analogue Scale