This is a pilot study. Chronic LBP is a major health care problem in Denmark. Few patients receive a specific diagnosis, leaving the majority of patients diagnosed with non specific low back pain(NSLBP). Classification systems can help to guide the treatment of NSLBP. This pilot study will compare manual therapy (manipulation and soft tissue treatment)and exercises to a classification based biopsychosocial intervention (a cognitive/functional approach) as described by Peter O'Sullivan, on a subgroup called "flexion pattern"

This pilot study has three specific aims:

(i) To determine the mean and standard deviation on the numerical rating scale of participants in this setting who have a motor control flexion pattern, so that sample size calculations for a fully powered randomized controlled trial could be performed.

(ii) To test the logistical and practical procedures that will be required to perform a fully powered randomized controlled trial using these two treatments.

(iii) To gain a preliminary estimate of any difference in the effect of these two treatments, so as to determine if the results of a fully powered randomized controlled trial might be clinically important and therefore worthwhile undertaking

This is a pilot study. Chronic LBP is a major health care problem in Denmark. Few patients receive a specific diagnosis, leaving the majority of patients diagnosed with non specific low back pain(NSLBP). Classification systems can help to guide the treatment of NSLBP.This project will recruit patients , classified with a "flexion pattern" according to the classification system proposed by Peter O´Sullivan. When classified with a flexion pattern the patients will be randomized into either of two treatment arms. Manual therapy (manipulation and soft tissue treatment)and exercises by a chiropractor or to a classification based biopsychosocial intervention done by a physiotherapist, (a cognitive/functional approach) as described by Peter O'Sullivan

This pilot study has three specific aims:

(i) To determine the mean and standard deviation on the numerical rating scale of participants in this setting who have a motor control flexion pattern, so that sample size calculations for a fully powered randomized controlled trial could be performed.

(ii) To test the logistical and practical procedures that will be required to perform a fully powered randomized controlled trial using these two treatments.

(iii) To gain a preliminary estimate of any difference in the effect of these two treatments, so as to determine if the results of a fully powered randomized controlled trial might be clinically important and therefore worthwhile undertaking

Inclusion Criteria:

Participants must be between 18 - 65 years old and have, with a history of low back pain more than three months.

The primary pain area from T12- to the gluteal folds. Low back pain must be provoked by movements and/or physical activities. Average pain intensity in the last two weeks must be al least: 4/10 on Pain numerical rating scale Participants must have adequate comprehension and expressing the Danish language.

Participants must be classified as having a "flexion pattern".

Exclusion Criteria:

Participants must not have been sick listed for more than 4 months; have an acute exacerbation of LBP, surgery of low limb within last 4 months or hip or knee osteoarthritis limiting loading of knee and hip flexion.

Follow medical conditions are also excluding participants:

A history of spinal surgery Radicular pain (disc prolapse or foraminal stenosis): non painful symptoms in leg, clinical signs of altered nerve conduction) Spinal stenosis A previous history psychiatric disease Current pregnancy Widespread non-specific pain (for filling criteria for fibromyalgia) Imaging confirming spondylolisthesis

Other diseases:

Rheumatoid arthritis ankylosing spondylitis neurologic disease infection cancer previous history of osteoporosis The patient can´t be classified as having a flexion pattern Lack of compliance during the intervention: if a patient fails to turn up for more than one appointment with out prior notice.

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