The diaphragm performs many functions that are vital to the body as a whole. Some of them are not related only to ventilation. The diaphragm is part of the myofascial system in the human body. Therefore, the proper functioning of the diaphragm should be a significant element of physiotherapy, e.g. in patients reporting pain in the lumbosacral spine.

Considering the complex role of the diaphragm, it seems reasonable to investigate the influence of the mobilization of the diaphragm (aimed at reducing diaphragm tension) on the tension of the extensor muscles of the lumbar spine.

The assumption of this reserach is to investigate the correlation between the tension of the fascia in the area of the diaphragm to the tension of the muscles in the area of the lumbar spine. The fascial connections between the diaphragm and the muscles in the lumbar spine presented above suggest that the manual therapy performed within the diaphragm can effectively prevent the occurrence of pain, and might be a supportive measure in the treatment of pain in the spine.

The aim of the study is to investigate the corellation between the tension of the fascia within the diaphragm and the tension of the posterior superficial tape.

Research questions:

1. How does manual therapy in the area of the tendon attachments of the diaphragm affect the relaxation of the extensor muscles of the lumbar spine?
2. How can the therapy conducted only within the diaphragm, without interfering with the structures surrounding the spine, reduce the tension of the extensor muscles of the lumbar spine and, consequently, increase the range of its mobility in all planes?
3. How will the introduced therapy change the tidal volume of the lungs?

Inclusion Criteria:

• age within 20-40 yrs,
• BMI within normal range (18.5-24.9)
• lack of abdominal obesity
• lack of chronic musculoskeletal conditions
• written, conscious consent

Exclusion Criteria:

• former abdominal surgery
• abdominal diseases (i.e. (np. kidney stones, ulcers, irritative bowel sindrome, etc.),
• pregnancy
• fever,
• tumors,
• blood hypertension,
• former surgery of respiratory system ,
• condition after surgical procedures in the area of the spine,
• the occurrence of pain in the spine in the 3 months preceding the research experiment,
• lack of conscious consent