A repeated movement exam according to MDT will be completed to note centralisation, peripheralization , and detect directional preference. The patient will be asked to perform 10 repeated movements in flexion, extension, lateral side glides direction and the participant will be asked to report if symptoms became more proximal (centralisation), more distal (peripheralization) better or worse or if there was no change after the repetitions. The direction identified as providing centralization or the best pain response will be identified as the directional preference.

The Spinal Appearance Questionnnaire (SAQ) consists of 11 pictogram questions and 12 multiple choice questions and an open question to assess the perceived appearance. A perceived appearance score (10-50) and an expectation score 4-20 will be calculated by averaging relevant items. A low score indicate good perceived appearance /50 and expectation /20.

Fear Avoidance and Beliefs Questionnaire (FABQ). The FABQ was developed on the basis of the assumption that fear-avoidance beliefs play a major role in LBP-related disability. It comprises 16 items scored by the patient and includes sub-scores for fear-avoidance beliefs regarding work (0-42) and physical activity (0-24). A higher score indicates more strongly held fear avoidance beliefs.

Oswestry Disability Index (ODI). The ODI uses 10 questions with 5 answer options to assess the degree of disability associated with spinal disorders. The total score is out of 100 starting with 0. High score indicate high disability.

The modified Orebro Musculoskeletal Pain questionnaire (short version) is a 12 items questionnaire which assess pain and psycho social factors. 100 is the worst score and 0 the best.

Work Ability Index is a 5 items questionnaire which assess the perceived ability to work. 38 is the best and 5 the worst.

The International Physical Activity Questionnaire (short) assesses the time spent per the participant to do different level of physical activity during a week in minutes. The time spent at each activity levels is converted to a MET score for the each patient. High MET indicate more physical activity was performed.

Photographies with landmarks: Posture photographs of the front and back and side profile of the participants will be collected to later extract the Posterior and Anterior Trunk Symmetry Indices (POTSI and ATSI). A plumbline and a flexicurve are used to assess the curves. High POTSI and ATSI scores indicate large deformity. High kyphosis and lordosis indices indicate hyperkyphosis and lordosis respectively.

Inclinometer to measure Range of motion in degree, the measurement of the lumbar flexion, extension and lateral flexion between T12L1 and S1 and the measurement of the thoracic flexion, extension and lateral flexion will be captured in degrees with double inclinometer technique between C7T1 and T12L1. The hip flexion is measured with the inclinometer on the front part of the tight. The straight leg raise and the prone knee bend test are measured with the single inclinometer on the front part of the ankle in both techniques. Higher degree readings indicate higher range of motion for all movements recorded with inclinometer (s).

Goniometer in degree. The range of each hip abduction is recorded by the goniometer. Higher degree readings indicate higher flexibility. The range of thoracic rotation between a 2 meters stick and the lateral edge of the table is recorded to the nearest degree with a goniometer to indicate full spine rotation. Higher ranges indicate more flexibility.

Back Range Of Motion tool will be used to measured the degree or lumbar rotation available in the lumbar spine. Higher degrees indicate more flexiblity.

Pic/Touch sensation on the lower limbs for each dermatome from L1 to S1. The examiner assesses for each dermatome if the participant discriminate most of the time the pic and the touch sensation or not. The front hip, front tight, medial knee, medial ankle, dorsal part of the big toe, heel, and the back of the knee are tested. Responses are recorded for each dermatomes on each side as can discriminates most of the time, does not discriminate most of the time and does not fell contact.

Strength of the lower limbs for each myotome from L1 to S1 measures with a dynamometer in pounds. The higher the score is higher the strength is. The hip flexion, knee extension, foot flexion/extension/eversion, and big toe extension are tested.

Patellar and Achilles Reflexes (hypereactive/hyporeactive/normal) are tested with an reflexe hammer. Reported as hyper, hypo or normal.

Prone Knee Bend (PKB) (knee flexion in a prone position) and Straight Leg Raise (SLR) (hip flexion with the knee extended in a supine position) tests. We recorde the range of motion in degree with the inclinometer and whether pain is produced pain or not by these tests.

Spirometer volumes (in liters): vital capacity, forced expiratory vital capacity, forced expiratory vital capacity after 1 sec (FEV1), FEV1 in % of maximal vital capacity. Flows (Liter/Sec): Maximal expiratory flow, Maximal expiratory flow at 25, 50, 75 % of the vital capacity, maximal inspiration flow. Higher are the volumes and flow better it is.

The Beighton score is a 9 point score which assess general flexibility of the limbs (the examiner searches for any hyperextension of the elbows and the knees, the ability to touch the floor with the palms (knee extended), maximal 5th finger extension exceeding 90 dgegrees and ability to touch the forarm with the thumb. 9 is hypermobile, 0 is normal.

Prevalence in each of the treatment based classification algorithm classification: manipulation, stabilisation, specific exercise. The classification is based on the clinical findings described in the other outcomes and the algorithm is followed to classify if possible the participants in these 3 treatment categories (cf Fritz Subgrouping Patients With Low Back Pain: Evolution of a Classification Approach to Physical Therapy 2007 JOSPT)

Patho-anatomical classification: Disc, disc+nerve root involvement, sacro iliac joint, spinal stenosis, spondylolisthesis. The research team classify (if possible) the participant in one of the categories based on the exam clinical findings(other outcomes listed above). Clinical criteria presented in Clinical classification in low back pain: best-evidence diagnostic rules based on systematic reviews by Petersen et al in 2017 are used to inform classification decisions.