Pragmatic individualised osteopathic manual treatment which is a system of diagnosis and treatment for a wide range of musculoskeletal conditions. Osteopaths take a detailed case history and perform a thorough clinical examination to help understand the nature of patients' pain and symptoms so that they can arrive at a diagnosis. Practitioners use touch, physical manipulation, stretching and massage to help increase the mobility of joints, to relieve muscle/joint tension and pain. Osteopaths often combine a range of other treatment techniques in their approach, such as rehabilitative exercises, advice about how patients can self-manage their condition and educational approaches to help them understand their pain. Osteopathy is a regulated profession (regulated by the General Osteopathic Council) in the UK

As for the active comparator + biopsychosocial management: after having a completed a 8-10 hour e-learning on the biopsychosocial model for the management of low back pain, osteopaths will use the same approaches as in the active comparator group, plus techniques to help patients making sense of their symptoms, to develop patients' self-efficacy, and psychosocial management skills.

includes touch, joint manipulations, stretching and massage

11-item unidimensional measure of pain intensity. The Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials recommendations will be used, i.e. patients will be presented with the numbers from 0 to 10, with 0 meaning 'No pain' and '10' meaning 'Pain as bad as you can imagine,' accompanied by the instructions "Please rate your pain by indicating the number that best describes your pain on average in the last 24h". NPRS is an acceptable measure but should not be used on its own as patients with chronic pain find it does not capture the complexity of their pain experience. It has a high test-retest reliability and a good validity. Patients will be asked to complete the NPRS every day, taking approx. 1 min.

PSFS measures functional change in patients with musculoskeletal disorders. Patients choose to list up to 5 activities that they have difficulty with or are unable to perform. They will be asked to continue recording data for the originally chosen activities but can add extra activities if goals change (e.g. due to improving or worsening symptoms). Patients will rate current level of difficulty for each activity on an 11-point scale, where 0 = unable to perform and 10 = able to perform at previous level. Mean averages are calculated by summing the difficulty ratings and dividing by the number of activities. The PSFS is reliable and responsive for patients with chronic low back pain and a Minimum Detectable Change (MDC) is considered to be 3 points for 1 activity or 2 points for the average of 2 or more activities.

MYMOP2 is a self-report questionnaire that lists one or two symptoms and one activity affected by the patient's condition. The first activity the patient participant created in PSFS will automatically be entered into the text of MYMOP2. The follow-up questionnaire is shorter but allows addition of a third symptom. MYMOP2 is a validated, sensitive and responsive outcome measure. A minimum clinically important change (MCIC) in score should be between 0.5-1.0, and any change greater than 1.0 is considered clinically significant. Patients will be asked to complete MYMOP2 once a week, taking approx. 5 min.

At the end of their course of treatment, patients will be asked to complete a final. This questionnaire has been adapted from the Patient Enablement Index for Back Pain and contains 12 questions to assess patients' perceptions of shared decisions making, treatment outcomes, relevance of the measures and acceptability of the data collection processes.