Inclusion Criteria:  Signed informed consent form Able to comply with the study protocol, in the investigator's judgment Aged 20-40 years, inclusive Healthy as determined by the Investigator based on medical history, physical examination, vital signs and neurological examination Waist-to-height ratio < 0,59  Exclusion Criteria:  Low back pain (acute or chronic) Previous abdominal or spine surgery Acute or chronic respiratory or musculoskeletal disorder Any clinically significant illness, medical/surgical procedure or trauma within 4 weeks before initiation of the study Pregnancy