The purpose of the research study is to assess the impact of traction forces on changes in systemic markers concentrations of spinal structure damage in people with obesity. The research group will include 40 subjects aged 35-60 with simple obesity (BMI ≥ 30 kg / m2) and chronic lumbar spine pain syndrome.

The control group will consist of 20 subjects with normal body weight suffering from the same pain, at a similar age to the patients in the study group. Persons will be qualified for examination by a specialist in internal medicine and a physiotherapist.

To assess the degree of structural damage within the intervertebral disc and adjacent anatomical structures, patients will undergo magnetic resonance imaging of the lumbosacral spine (MRI 1.5T, standard in 3 projections). Patients will undergo traction therapy under the supervision of a physiotherapist. The application of traction forces on the traction table (ST6567P-SEERSMEDICAL) will last 30 minutes a day for 4 weeks (continuous traction mode with a maximum strength of 30% of the patient's body weight).

Twice, before and after therapy, the following will be assessed: (1) body composition (by DXA method), (2) other anthropometric indicators, (3) functional parameters of the spine: mobility (electrogoniometer), muscle bioelectric signal amplitude (electromyograph), soft tissue biophysical parameters (myotonometer), (4) pain threshold and intensity in the lumbar region (using an algometer and validated questionnaires), (5) disability caused by pain in the spine (Oswestry questionnaire), (6) blood biochemical indicators selected on the basis of the latest research on biomarkers of spinal damage (for this purpose, 25ml venous blood will be taken from the subjects).

Blood levels of interleukin-17, interleukin-4, interleukin-2 (IL-2), interleukin-10 (IL-10), differentiating growth factor 15 (GDF-15), leptin, adipsin, chemokine CCL5 (RANTES), stem cell growth factor β (SCGF-β), vascular endothelial growth factor (VEGF), neuropeptide Y, and chondroitin sulfate CS846 will be determined in the blood of the subjects. It is planned to assess the relationship of the studied biomarkers with the degree of disk degeneration, obesity, lean and fat body mass, pain intensity, and functional indicators of the spine. Patients will be asked to stop taking anti-inflammatory drugs during therapy and at least 24 hours prior to blood sampling.

People suffering from obesity are particularly vulnerable to mechanical compression of the intervertebral discs, and as a result their degeneration, hernia and pressure on the nerve roots, which together cause inflammation and pain in the damaged area. This is a significant public health problem due to the 100% incidence of pain syndrome among people with obesity. The use of traction forces has beneficial effects on degenerated intervertebral discs, but there are no studies assessing the effectiveness of the traction method in relation to a group of obese people with back pain syndrome.

Beneficial biochemical changes in the blood, alleviation of pain, improvement of functional parameters of the spine are expected after application of traction forces to the patients in the mechanism of decompression of the destroyed and being in chronic inflammation intervertebral discs. Identification of biomarkers enabling to monitor the effects of therapies in patients with chronic back pain can become a contribution to change standards in the diagnosis of back pain and reorientation in its treatment to real causes.

Inclusion Criteria:

1. Written consent to participate in the study,
2. Age: 35 - 60 years,
3. Obesity (BMI ≥ 30 kg / m2) or normal weight (BMI 18,5-29,9 kg/m2),
4. Stable body weight in the last month ± 2 kg,
5. Chronic low back pain.

Exclusion Criteria:

1. Secondary form of obesity;
2. Serious neurological defects (including large muscle losses, sensory disturbances in a large area of the lower limb, occurrence of cauda equina syndrome);
3. Surgery, post-accident mechanical injuries, history of spine fractures;
4. History of rheumatic disease (RA, ankylosing spondylitis, systemic lupus);
5. Osteoporosis;
6. Pain located in a location other than the spine which is more severe than the low back pain;
7. Poorly controlled type 2 diabetes;
8. Poorly controlled hypertension (mean systolic blood pressure> 140mmHg and / or average diastolic blood pressure> 90mmHg) during the last month and / or the necessity of modification of pharmacological treatment;
9. Lipid disorders requiring the introduction of pharmacological treatment in the last 3 months before observation or during observation;
10. Acute coronary event, unstable angina, stroke or transient cerebral ischemia in the last 6 months;
11. Features of heart failure in physical examination and / or additional tests (chest X-ray, echocardiography);
12. Clinically significant arrhythmias, conduction disorders, pacemaker implantation;
13. Fainting in an interview,
14. Chronic kidney disease with creatinine clearance <60mL / min / 1.73m2;
15. Clinically significant liver dysfunction (transaminases exceeding 3 times the normal range);
16. Acute or chronic, clinically apparent inflammatory process of the respiratory tract, inflammatory processes of the genitourinary system, inflammatory process in the head and neck;
17. Acute infection in the last month;
18. Cancer;
19. Alcohol abuse, drug addiction;
20. Pregnancy;
21. Uncontrolled mental illness that may falsify test results;
22. Other conditions which may pose any risk to the patient during the observation.