The purpose of the study is to determent whether there is a difference between two types of treatments in physiotherapy (individual vs group) for patients with low back pain (LBP), in terms of their sensation of how they have been helped and their treatments' outcomes measures. The study hypothesizes are: a) Based on the results of literature review which does not reveal a clear difference between group and individual treatments' outcomes for LBP, it is hypothesized that no difference will be found in treatment results for the two types of group treatments in the present study also, b) The assumption is that different distribution of therapeutic factors will be found in the two types of treatments (individual, group), C) Patients' sensation of how they have been helped will be connected to treatment results.