problem of recruitment (not enough patients)

The purpose of this study is:

- To validate or not the interest of the classification using the pragmatic application of clinical predictive rule for low back pain to identify patients with good prognosis following a brief spinal manipulation intervention.

Patients (n = 100 to 150) :

Recruited from emergency department of Saint-Luc hospital by medical doctors

Inclusion criteria:

A. Non-specific (No red flags) acute low back with mobility deficit (limitation in bending) and a pain duration < 16 days and no symptoms distal to the knees, male and female patients aged 19-55 years.

Exclusion criteria:

• Specific LBP (red flags) and radiating beyond the knee
• Low Back Pain Non-specific subacute and chronic
• Recurrent low back pain (more than 3 painful episodes)
• Lumbar instability or hyper laxity (instability catch, active straight leg raise (SLR) > 90°, aberrant movement,range of motion (ROM) of le lower lumbar spine > 50° during standing flexion), pregnancy and post-partum status
• High irritability = necessity of opioid medication or intravenous injection of medication in the emergency department
• previous history of surgical intervention in the low back area

Intervention:

- 3 sessions within one week of spinal manipulation (thrusts, grade V)

comparison:

- 3 sessions of false/sham manipulation (placebo) in side lying on thoraco-lumbar hinge in a grade II

Co-intervention similar in both group:

= traditional medical care (TMC)

- Reassure patients, avoid bed rest, advise them to stay active and to take analgesics (if needed such as paracetamol) (European Guidelines for non-specific acute low back pain ; van Tulder et al. 2006 ; Koes et al. 2010).

Outcomes:

Use of effect sizes by standardized mean of difference. ANOVA one and Two Way, number needed to treat (NNT) analysis and intention to treat analysis on all outcome variables:

• Primary: Kinematic Variables: two indices, logit score for the amplitude and velocity (Hidalgo et al., 2012) and patient's expectation from manual therapy (MT) treatment to improve his LBP
• Secondary: Pain in the presentation with visual analogical scale (VAS) and the repartition (body diagram), Oswestry Disability Index (ODI, questionnaire on pain and function), patient specific function (PSF), fear avoidance beliefs questionnaire (FABQ), Start back tool, physical examination, medication use, return to work and treatment side effects, patient's belief in a real MT intervention or not (at the end of the follow-up)

Study design:

• Double blind ie: patients and assessors blind.
• The methodological quality of the study is the 8-9/10 on the PEDro scale, we will strictly follow the CONSORT statement and will be register in clinical.trials gov

Evaluators:

Christine Detrembleur (PT-PhD-UCL), Maxime Gilliaux (PT-PhD-student-UCL)

Responsible for the study: Henri Nielens (MD-PhD-UCL)

Practitioner and investigator:

Benjamin Hidalgo PE, PT-MT, DO, PhD-student Certificate in Orthopedic Manual Therapy (Manual Concepts, Curtin University) Assistant-Professor Faculty of Physical therapy (FSM-UCL) Belgium

International collaborator:

Timothy Flynn (PT-PhD), Regis University, Denver, USA

INTRODUCTION:

Non-specific low back pain is a high prevalence within musculoskeletal disorders in industrialized countries (Waddell 2004). Many treatments are available with different degrees of effectiveness (Delitto et al. 2012). Many experts agree that sub-groups exist within the large category of patients diagnosed with non-specific LBP. The difficulty in identifying pathoanatomical causes in most patients combined with the high false positive rates of imaging studies have led many to further conclude that meaningful sub-groups should be based on patient's symptoms and clinical presentation (Fritz et al; 2005; Hidalgo et al. 2012, 2013a,b). The identification of subgroups could improve the outcomes of clinical care by establishing more accurate prognoses, efficiently directing patients to therapies most likely to benefit their particular sub-group (Fritz et al. 2005; Delitto et al. 2012).

Orthopaedic Manual Therapy (OMT) plays an increasingly important role in the treatment of back pain, especially in patients with factors predicting a favorable response to the TMO (Delitto et al. 2012, Fritz et al. 2005).

One proposed subgroup among non-specific LBP people that has been identified is patients who respond rapidly to spinal manipulation when positive on clinical predictive rule (4-5/ 5 criteria) (Flynn et al. 2002, Child et al. 2004, Fritz et al. 2005). However common sense, as well as research evidence recognizes that not all patients with LBP should expected to respond to a manipulation intervention. The efficiency of primary care management of patients with LBP could be improved if a pragmatic tool could help to identify those patients with LBP who are likely to respond to this hands on approach.

In the study of Fritz et al. 2005, authors demonstrated that 2 easy clinical criteria are sufficient to identify this subgroup among non-specific LBP (duration of symptom <16 days and distribution of symptoms : not having symptoms distal to the knees).

However, the methodological quality of studies in physical therapy is often not good that is to say, there is only sparse good level 1 A or B (double blind: in terms of patients and evaluators blinded).

As there is no Level 1 A study to validate the pragmatic application of a clinical prediction rule in primary care to identify patients with LBP with a good prognosis following a brief spinal manipulation intervention. We would like to realize this validation study.

Moreover, in the previously studies, the assessment tools were mainly questionnaires assessing pain, disability and function. We have developed a quantitative tool to assess the kinematics of the lumbar spine during trunk movements in different directions. This tool is validated and is enabled to give quantitative evaluation of the variables of ROM and speed for different segments of the spine, before, during and after treatment with TMO (Hidalgo et al. 2012; 2013c).

Standard disability questionnaires will also be used as secondary outcome measures, because we believe that the kinematics of the spine should be the variable most sensitive to change.

The purpose of this study is:

• To validate or not the interest of the classification using the pragmatic application of CPR in low back pain to identify patients with LBP with good prognosis following a brief SM intervention.
• To analyze the quality of active trunk movements with the validated kinematic spine model (ROM and speed of different segments) and the benefit obtained or not during these movements in patients with low back pain before and after application of an effective spinal manipulation (SM) treatment and a placebo/sham SM.
• Analyze the effect of treatment on responses to questionnaires before and after these treatments

Method:

Subjects:

Patients will be recruited from primary car by medical doctors when they present to the emergency department clinics University St-Luc (Prof. Frederic Thys, Dr. Christophe Bastin, Dr. Virginie Fraselle).

They will receive a clinical examination by emergency department physicians to ensure that they correspond to the primary criteria for inclusion:

1. NO RED FLAGS,
2. + on the pragmatic application of CPR (+ on 2 criteria: pain < 16 days and no symptoms distal to the knees),
3. Activity and participation: limitation in bending

Baseline examination:

If patients meet the criteria for inclusion, then they will receive a baseline examination:

1. kinematic analysis of movements of the trunk using the method developed by Hidalgo et al. 2012 with two index, one for ROM and the other for the SPEED
2. body diagram to indicate the anatomical distribution of symptoms
3. VAS to measure the current/present intensity of pain
4. Start back tool
5. Fear avoidance beliefs questionnaire
6. The modified Oswestry questionnaire
7. The Patient specific functional scale (PSFs)
8. The patient belief to the spinal manipulation in improving his LBP (from 0 to 10)
9. Recording of medication consumption, return to work and side effects of treatment
10. Physical examination to record the presence of hypomobility of lumbar spine and hips rotation
11. Physical examination to record specific combined trunk movements that is pain provocative and the lumbar levels of involvement according to the method developed in Hidalgo et al. 2013 a.

Treatment:

Consistent with the current evidence regarding the classification of low back pain patient, clinical reasoning and OMT (Delitto et al., 2012) will be done as follows:

- Lumbopelvic manipulation in supine (A) or in side-lying (B) positions for subjects with LBP (Flynn et al 2002, 2004; Fritz et al. 2005; Cleland et al. 2006; Delitto et al. 2012).

The spinal manipulative intervention A or B will be choose according to the patient and practitioner comfort and expectation of a good biomechanical action (supposed by a pop or cavitation sound) who will generate neurophysiological effects.

If for example the position A is the best for both patient-practitioner but after a maximum of two trials doesn't produce a pop sound then the practitioner will move to the B position for a maximum of two trials as well.

Examples of lumbopelvic manipulation :

A. Patient supine : side bending to one side and rotation to the other side. E.g. side bending right and rotation left for a pain on the right side.

B. Patient side lying : e.g. side lying left for a pain on the right side :

Patients will be randomized in an intervention group and a control group (placebo/sham spinal manipulation).

The sham SM will realize to mimic (i) the same time, (ii) interaction and (iii) action with the manual therapist but without any efficacy in the way that the patient think that he receive an effective SM. For that the MT will use the position B using the upper body of the patient to target the thoraco-lumbar hinge and not the lumbopelvic region and take the time of handling the patient like in a true SM and mimic a high velocity and short ROM action moving fast his body but with a minimal action on the patient's body.

Data analysis :

Primary outcome :

The analysis of the pathological motion requires the acquisition of kinematic variables during movement of body segments (kinematic variables). They are recorded using 8 infrared cameras at various trunk movements (Hidalgo et al. 2012).

• Recording of segmental kinematic variables Nine reflective markers placed at different anatomical landmarks chosen. These markers are attached either by means of double-sided stickers or using extensible ribbon. Using eight infrared cameras, the coordinates of each of these nine markers are recorded. This allows us to determine the evolution of the angular displacement of the segments in three planes of space.

Secondary outcomes :

All the primary and secondary outcomes will be treated in an intention to treat analysis.

Inclusion Criteria:

• non specific acute low back pain < 16 days,
• no pain below the knee,
• mobility deficit

Exclusion Criteria:

• specific low back pain (red flags),
• subacute or chronic non-specific LBP,
• previous history of surgery,
• high irritability,
• hyperlaxity - aberrant movement when standing flexion,
• post part um and pregnancy