Exercise Therapy for Recurrent Low Back Pain: Unraveling the Puzzle of Peripheral Muscle and Central Brain Changes

Study Overview
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Brief Summary
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Exercise therapy has been shown to be effective in decreasing pain and improving function for patients with recurrent low back pain (LBP). Research on the mechanisms that trigger and/or underlie the effects of exercise therapy on LBP problems is of critical importance for the prevention of recurring or persistence of this costly and common condition. One factor that seems to be crucial within this context is the dysfunction of the back muscles. Recent pioneering results have shown that individuals with recurring episodes of LBP have specific dysfunctions of these muscles (peripheral changes) and also dysfunctions at the cortical level (central changes). This work provides the foundation to take a fresh look at the interplay between peripheral and central aspects, and its potential involvement in exercise therapy. The current project will draw on this opportunity to address the following research questions: What are the immediate (after a single session) and the long-term effects (after 18 repeated sessions) of exercise training on: (1) back muscle structure; (2) back muscle function; (3) the structure of the brain; (4) and functional connectivity of the brain. This research project also aims to examine whether the effects are dependent on how the training was performed. Therefore a specific versus a general exercise program will be compared.

Detailed Description
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Although the cause of persistent non-specific LBP remains unknown, structural and functional alterations of the brain and paravertebral muscles have been proposed as underlying mechanisms. As it is hypothesized that these alterations contribute to, or maintain non-specific LBP, exercise therapy is a key element in the rehabilitation of reoccurring LBP. Specific training of sensorimotor control of the lumbopelvic region (i.e. specific skilled motor training) has shown to decrease pain and disability in patients with LBP, but has not been found superior to other forms of exercise training regarding improvements in clinical outcome measures. On the other hand, this type of training seems to differentially impact the recruitment of the back muscles compared to general exercise training. However, research using multiple treatment sessions and including follow-up outcome assessments is scarce. Furthermore, it is unknown if improvements may be attributed to measurable peripheral changes in the muscle and/or central neural adaptations in the brain. The primary aim of this study is to examine the short and long-term effects of specific skilled motor control training versus unspecific general extension training on pain, functional disability, brain structure/function and muscle structure/function in recurrent LBP patients. Method: In this double-blind, randomized controlled clinical trial 62 recurrent LBP patients will be randomly allocated (1:1) to receive either specific skilled motor training (i.e. the experimental group) or general extension training (i.e. control group). Each training group will receive 13 weeks of treatment, during which a total of 18 supervised treatment sessions will be delivered in combination with an individualized home-exercise program. Both groups will first receive low-load training (i.e. at 25-30% of the individual's repetition maximum, sessions 1-9) followed by high-load training (i.e. at 40-60% of the individual's one repetition maximum, sessions 10-18). Primary outcome measures include: LBP-related pain and disability (RMDQ, NRS and Margolis pain diagram), lumbar muscle structure and function (Dixon MRI and mf-MRI) and brain structure and function (MRI, DTI and fMRI). Secondary measures include: lumbopelvic control and proprioception (thoracolumbar dissociation test and position-reposition test), trunk muscle activity (RAM and QFRT) and psychosocial factors, including measures of physical activity (IPAQ-LF, SF-36), pain cognitions and perceptions (PCS, PCI and PVAQ), anxiety and depression (HADS), and kinesiophobia (TSK). Experimental data collection will be performed at baseline, immediately following the low-load training (i.e. after the 9th supervised treatment session), following the high-load training (i.e. after the 18th supervised treatment session), and at 3 months follow-up. Experimental data collection will comprise of magnetic resonance imaging of the brain and trunk muscles, clinical assessments assessing muscle function, and a battery of questionnaires evaluating psychosocial factors.

Official Title
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Efficacy of Specific Skilled Motor Versus General Exercise Training on Peripheral Muscle and Central Brain Alterations in Patients With Recurrent Low Back Pain

Conditions
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Low Back Pain, Recurrent

Intervention / Treatment
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* Behavioral: Specific skilled motor training
* Behavioral: General extension training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: History of non-specific recurrent LBP with the first onset being at least 6 months ago At least 2 episodes of LBP/year, with an 'episode' implying pain lasting a minimum of 24 hours which is preceded and followed by at least 1 month without LBP Minimum LBP intensity during episodes should be ≥2/10 on a numeric rating scale (NRS) from 0 to 10 During remission the NRS intensity for LBP should be 0. LBP should be of that severity that it limits activities of daily living LBP should be of that severity that a (para)medic has been consulted at least once regarding the complaints Flexion pattern of LBP Exclusion Criteria: Chronic LBP (i.e. duration remission <1 month) Subacute LBP (i.e. first onset between 3 and 6 months ago) Acute (i.e. first onset <3 months ago) LBP Specific LBP (i.e. LBP proportionate to an identifiable pathology, e.g. lumbar radiculopathy) Patients with neuropathic pain Patients with chronic widespread pain as defined by the criteria of the 1990 ACR (i.e. fibromyalgia) A lifetime history of spinal traumata (e.g. whiplash), surgery (e.g. laminectomy) or deformations (e.g. scoliosis) A lifetime history of respiratory, metabolic, neurologic, cardiovascular, inflammatory, orthopedic or rheumatologic diseases Concomitant therapies (i.e. rehabilitation, alternative medicine or therapies) Contra-indications for MRI (e.g. suffering from claustrophobia, the presence of metallic foreign material in the body, BMI >30kg/m²) Professional athletes Pregnant women Breastfeeding women Women given birth in the last year before enrolment

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The study model is parallel. Participants experiencing recurrent LBP patients will be randomly allocated (1:1) to receive either specific skilled motor training or general extension training (i.e. parallel study model). Both groups will first receive low-load training (i.e. at 25-30% of the individual's repetition maximum, sessions 1-9) followed by high-load training (i.e. at 40-60% of the individual's one repetition maximum, sessions 10-18) (i.e. cross-over study model).
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Specific skilled motor training<br>13 weeks of treatment, with 18 supervised treatment sessions in combination with an individualized home-exercise program. This group will first receive low-load training (i.e. at 25-30% of the individual's repetition maximum, sessions 1-9) followed by high-load training (i.e. at 40-60% of the individual's one repetition maximum, sessions 10-18). | Behavioral: Specific skilled motor training<br>* Participants allocated to the skilled motor training group will receive sensorimotor training of the intrinsic muscles of the lumbopelvic region, namely the multifidus, transversus abdominis, and pelvic floor muscles.<br>|
| Active Comparator: General extension training<br>13 weeks of treatment, with 18 supervised treatment sessions in combination with an individualized home-exercise program. This group will first receive low-load training (i.e. at 25-30% of the individual's repetition maximum, sessions 1-9) followed by high-load training (i.e. at 40-60% of the individual's one repetition maximum, sessions 10-18). | Behavioral: General extension training<br>* Participants allocated to the general extension training group will receive general training exercises using the David Back equipment from the Back Unit at Ghent University Hospital<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Brain macro-structure | Whole brain T1-weighted structural MRI will be acquired. | Baseline | 
| Brain macro-structure | Whole brain T1-weighted structural MRI will be acquired. | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Brain macro-structure | Whole brain T1-weighted structural MRI will be acquired. | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Brain macro-structure | Whole brain T1-weighted structural MRI will be acquired. | At 3 months follow-up | 
| Brain micro-structure | Whole-brain T2-weighted images will be obtained. | Baseline | 
| Brain micro-structure | Whole-brain T2-weighted images will be obtained. | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Brain micro-structure | Whole-brain T2-weighted images will be obtained. | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Brain micro-structure | Whole-brain T2-weighted images will be obtained. | At 3 months follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Functional brain connectivity | Resting-state functional MRI will be performed to acquire insight into subnetworks relating to sensorimotor control and pain processing. | Baseline | 
| Functional brain connectivity | Resting-state functional MRI will be performed to acquire insight into subnetworks relating to sensorimotor control and pain processing. | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Functional brain connectivity | Resting-state functional MRI will be performed to acquire insight into subnetworks relating to sensorimotor control and pain processing. | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Functional brain connectivity | Resting-state functional MRI will be performed to acquire insight into subnetworks relating to sensorimotor control and pain processing. | At 3 months follow-up | 
| Lumbar muscle structure | T1-weighted Dixon MRI will be performed. | Baseline | 
| Lumbar muscle structure | T1-weighted Dixon MRI will be performed. | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Lumbar muscle structure | T1-weighted Dixon MRI will be performed. | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Lumbar muscle structure | T1-weighted Dixon MRI will be performed. | At 3 months follow-up | 
| Lumbar muscle function | T2-weighted mf-MRI will be conducted. | Baseline | 
| Lumbar muscle function | T2-weighted mf-MRI will be conducted. | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Lumbar muscle function | T2-weighted mf-MRI will be conducted. | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Lumbar muscle function | T2-weighted mf-MRI will be conducted. | At 3 months follow-up. | 
| Lumbopelvic control | Lumbopelvic control will be examined by means of a clinical thoracolumbar dissociation test which assesses the quality of performance of lumbopelvic motion with limited motion at the thoracolumbar junction. | Baseline | 
| Lumbopelvic control | Lumbopelvic control will be examined by means of a clinical thoracolumbar dissociation test which assesses the quality of performance of lumbopelvic motion with limited motion at the thoracolumbar junction. | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Lumbopelvic control | Lumbopelvic control will be examined by means of a clinical thoracolumbar dissociation test which assesses the quality of performance of lumbopelvic motion with limited motion at the thoracolumbar junction. | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Lumbopelvic control | Lumbopelvic control will be examined by means of a clinical thoracolumbar dissociation test which assesses the quality of performance of lumbopelvic motion with limited motion at the thoracolumbar junction. | At 3 months follow-up. | 
| Lumbopelvic proprioception | To evaluate lumbar proprioception, the position-reposition accuracy of the lumbar spine will be determined. | Baseline | 
| Lumbopelvic proprioception | To evaluate lumbar proprioception, the position-reposition accuracy of the lumbar spine will be determined. | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Lumbopelvic proprioception | To evaluate lumbar proprioception, the position-reposition accuracy of the lumbar spine will be determined. | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Lumbopelvic proprioception | To evaluate lumbar proprioception, the position-reposition accuracy of the lumbar spine will be determined. | At 3 months follow-up. | 
| Anticipatory postural adjustments | To examine anticipatory postural adjustments (APAs) trunk muscle onset latencies in response to internal-induced perturbations will be measured by means of surface electromyography (EMG). APAs will be measured by inducing internal perturbations in the trunk muscles during a reliable and valid unilateral rapid arm movement task (RAM). | Baseline | 
| Anticipatory postural adjustments | To examine anticipatory postural adjustments (APAs) trunk muscle onset latencies in response to internal-induced perturbations will be measured by means of surface electromyography (EMG). APAs will be measured by inducing internal perturbations in the trunk muscles during a reliable and valid unilateral rapid arm movement task (RAM). | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Anticipatory postural adjustments | To examine anticipatory postural adjustments (APAs) trunk muscle onset latencies in response to internal-induced perturbations will be measured by means of surface electromyography (EMG). APAs will be measured by inducing internal perturbations in the trunk muscles during a reliable and valid unilateral rapid arm movement task (RAM). | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Anticipatory postural adjustments | To examine anticipatory postural adjustments (APAs) trunk muscle onset latencies in response to internal-induced perturbations will be measured by means of surface electromyography (EMG). APAs will be measured by inducing internal perturbations in the trunk muscles during a reliable and valid unilateral rapid arm movement task (RAM). | At 3 months follow-up | 
| Compensatory postural adjustments | To examine compensatory postural adjustments (CPAs), trunk muscle onset latencies in response to external-induced perturbations will be measured by means of surface electromyography (EMG). CPAs will be measured by using external perturbations of trunk muscles during a quick-force-release test (QFRT). | Baseline | 
| Compensatory postural adjustments | To examine compensatory postural adjustments (CPAs), trunk muscle onset latencies in response to external-induced perturbations will be measured by means of surface electromyography (EMG). CPAs will be measured by using external perturbations of trunk muscles during a quick-force-release test (QFRT). | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Compensatory postural adjustments | To examine compensatory postural adjustments (CPAs), trunk muscle onset latencies in response to external-induced perturbations will be measured by means of surface electromyography (EMG). CPAs will be measured by using external perturbations of trunk muscles during a quick-force-release test (QFRT). | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Compensatory postural adjustments | To examine compensatory postural adjustments (CPAs), trunk muscle onset latencies in response to external-induced perturbations will be measured by means of surface electromyography (EMG). CPAs will be measured by using external perturbations of trunk muscles during a quick-force-release test (QFRT). | At 3 months follow-up | 
| Nociceptive flexion reflex - threshold | The NFR will be elicited in the dominant leg by transcutaneous electrical stimulation of the sural nerve in its retromalleolar path using a stimulation bar electrode connected to a constant current stimulator. Surface EMG electrodes will be placed on the skin of the muscle belly of the ipsilateral biceps femoris. | Baseline | 
| Nociceptive flexion reflex - threshold | The NFR will be elicited in the dominant leg by transcutaneous electrical stimulation of the sural nerve in its retromalleolar path using a stimulation bar electrode connected to a constant current stimulator. Surface EMG electrodes will be placed on the skin of the muscle belly of the ipsilateral biceps femoris. | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Nociceptive flexion reflex - threshold | The NFR will be elicited in the dominant leg by transcutaneous electrical stimulation of the sural nerve in its retromalleolar path using a stimulation bar electrode connected to a constant current stimulator. Surface EMG electrodes will be placed on the skin of the muscle belly of the ipsilateral biceps femoris. | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Nociceptive flexion reflex - threshold | The NFR will be elicited in the dominant leg by transcutaneous electrical stimulation of the sural nerve in its retromalleolar path using a stimulation bar electrode connected to a constant current stimulator. Surface EMG electrodes will be placed on the skin of the muscle belly of the ipsilateral biceps femoris. | At 3 months follow-up | 
| Nociceptive flexion reflex - temporal summation | Five 1ms rectangular wave pulse train will be administered 3 times at a frequency of 2 Hz at a constant stimulation intensity. This procedure will be repeated 5 times. | Baseline | 
| Nociceptive flexion reflex - temporal summation | Five 1ms rectangular wave pulse train will be administered 3 times at a frequency of 2 Hz at a constant stimulation intensity. This procedure will be repeated 5 times. | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Nociceptive flexion reflex - temporal summation | Five 1ms rectangular wave pulse train will be administered 3 times at a frequency of 2 Hz at a constant stimulation intensity. This procedure will be repeated 5 times. | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Nociceptive flexion reflex - temporal summation | Five 1ms rectangular wave pulse train will be administered 3 times at a frequency of 2 Hz at a constant stimulation intensity. This procedure will be repeated 5 times. | At 3 months follow-up | 
| Conditioned pain modulation | The conditioning stimulus will comprise of immersion of the non-dominant hand until the proximal wrist crease in a hot circulating water bath of 45.5°C during 6 minutes. The test stimulus will comprise of pressure pain threshold (PPT) assessments (as described above) during and after completion of the conditioning stimulus. Before, after 2 min of immersion and 2 minutes after completion of immersion, the test stimulus will be repeated twice at each test location at the dominant body side. | Baseline | 
| Conditioned pain modulation | The conditioning stimulus will comprise of immersion of the non-dominant hand until the proximal wrist crease in a hot circulating water bath of 45.5°C during 6 minutes. The test stimulus will comprise of pressure pain threshold (PPT) assessments (as described above) during and after completion of the conditioning stimulus. Before, after 2 min of immersion and 2 minutes after completion of immersion, the test stimulus will be repeated twice at each test location at the dominant body side. | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Conditioned pain modulation | The conditioning stimulus will comprise of immersion of the non-dominant hand until the proximal wrist crease in a hot circulating water bath of 45.5°C during 6 minutes. The test stimulus will comprise of pressure pain threshold (PPT) assessments (as described above) during and after completion of the conditioning stimulus. Before, after 2 min of immersion and 2 minutes after completion of immersion, the test stimulus will be repeated twice at each test location at the dominant body side. | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Conditioned pain modulation | The conditioning stimulus will comprise of immersion of the non-dominant hand until the proximal wrist crease in a hot circulating water bath of 45.5°C during 6 minutes. The test stimulus will comprise of pressure pain threshold (PPT) assessments (as described above) during and after completion of the conditioning stimulus. Before, after 2 min of immersion and 2 minutes after completion of immersion, the test stimulus will be repeated twice at each test location at the dominant body side. | At 3 months follow-up | 
| Anxiety and depression | Hospital Anxiety and depression scale (HADS) | Baseline | 
| Anxiety and depression | Hospital Anxiety and depression scale (HADS) | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Anxiety and depression | Hospital Anxiety and depression scale (HADS) | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Anxiety and depression | Hospital Anxiety and depression scale (HADS) | At 3 months follow-up | 
| Physical activity | International physical activity questionnaire - long form (IPAQ-LF) | Baseline | 
| Physical activity | International physical activity questionnaire - long form (IPAQ-LF) | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Physical activity | International physical activity questionnaire - long form (IPAQ-LF) | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Physical activity | International physical activity questionnaire - long form (IPAQ-LF) | At 3 months follow-up. | 
| Pain coping | Pain coping inventory (PCI), Pain Catastrophizing Scale (PCS) | Baseline | 
| Pain coping | Pain coping inventory (PCI), Pain Catastrophizing Scale (PCS) | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Pain coping | Pain coping inventory (PCI), Pain Catastrophizing Scale (PCS) | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Pain coping | Pain coping inventory (PCI), Pain Catastrophizing Scale (PCS) | At 3 months follow-up | 
| Pain catastrophizing | Pain Catastrophizing Scale (PCS) | Baseline | 
| Pain catastrophizing | Pain Catastrophizing Scale (PCS) | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Pain catastrophizing | Pain Catastrophizing Scale (PCS) | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Pain catastrophizing | Pain Catastrophizing Scale (PCS) | At 3 months follow-up | 
| Pain vigilance and awareness | Pain vigilance and awareness questionnaire (PVAQ) | Baseline | 
| Pain vigilance and awareness | Pain vigilance and awareness questionnaire (PVAQ) | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Pain vigilance and awareness | Pain vigilance and awareness questionnaire (PVAQ) | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Pain vigilance and awareness | Pain vigilance and awareness questionnaire (PVAQ) | At 3 months follow-up | 
| Kinesiophobia | Tampa Scale for Kinesiophobia (TSK) | Baseline | 
| Kinesiophobia | Tampa Scale for Kinesiophobia (TSK) | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Kinesiophobia | Tampa Scale for Kinesiophobia (TSK) | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Kinesiophobia | Tampa Scale for Kinesiophobia (TSK) | At 3 months follow-up | 
| Health status | Short Form Health Survey-36 items (SF-36) | Baseline | 
| Health status | Short Form Health Survey-36 items (SF-36) | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Health status | Short Form Health Survey-36 items (SF-36) | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Health status | Short Form Health Survey-36 items (SF-36) | At 3 months follow-up | 
| Low back pain related pain | LBP related pain intensity will be evaluated by using an 11 point NRS | Baseline | 
| Low back pain related pain | LBP related pain intensity will be evaluated by using an 11 point NRS | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Low back pain related pain | LBP related pain intensity will be evaluated by using an 11 point NRS | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Low back pain related pain | LBP related pain intensity will be evaluated by using an 11 point NRS | At 3 months follow-up | 
| Low back pain related disability | The Roland Morris Disability Questionnaire will be used to evaluate disability. | Baseline | 
| Low back pain related disability | The Roland Morris Disability Questionnaire will be used to evaluate disability. | After low-load training phase (i.e. after 9th supervised treatment session) assessed at approximately 8 weeks | 
| Low back pain related disability | The Roland Morris Disability Questionnaire will be used to evaluate disability. | After high-load training phase (i.e. after 18th supervised treatment session) assessed at approximately 13 weeks | 
| Low back pain related disability | The Roland Morris Disability Questionnaire will be used to evaluate disability. | At 3 months follow-up | 
| Low back pain recurrence | Self-report via telephone interview: (1) the number of episode(s), (2) the duration of the LBP episode(s), (3) pain intensity, measured with three NRS for average-, worst- and current pain during the LBP episode(s), (4) location and quality of pain (i.e. sharp, burning, etc. sensation), (5) subjects opinion about what caused the new episode of LBP, (6) degree of impairments in daily life activities due to the LBP, (7) whether participants sought treatment (i.e. physiotherapist, general practitioner, etc.) and (8) strategies to cope with the new LBP episode. | At 6 months follow-up | 
| Low back pain recurrence | Self-report via telephone interview: (1) the number of episode(s), (2) the duration of the LBP episode(s), (3) pain intensity, measured with three NRS for average-, worst- and current pain during the LBP episode(s), (4) location and quality of pain (i.e. sharp, burning, etc. sensation), (5) subjects opinion about what caused the new episode of LBP, (6) degree of impairments in daily life activities due to the LBP, (7) whether participants sought treatment (i.e. physiotherapist, general practitioner, etc.) and (8) strategies to cope with the new LBP episode. | At 12 months follow-up | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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low back pain, motor control, exercise, randomized controlled trial