Low back pain has a great importance in today's society, and it is therefore important to develop an effective treatment for this condition. People with chronic nonspecific low back pain, can present respiratory disorders and get anxiety states, affecting mainly the diaphragm muscle. Therefore, given its direct anatomic relationship, the diaphragm may be part of the development of chronic low back pain. Although clinical practice guidelines for chronic low back pain have been developed, it hasn't been explored before a physiotherapy treatment especially aimed at a diaphragmatic treatment.