| To be enrolled in the study, the participant had to: |
| ∘ Fulfil informed written consent. |
| ∘ Have the ability to speak and read Danish. |
| ∘ Be between the age of 18 and 60. |
| ∘ Have a body mass index <35 |
| ∘ Have had LBP >3 months, defined as pain on the posterior aspect of the body between the 12th thoracic vertebrae and the gluteal folds. |
| ∘ Have no previous back surgery and not have had surgery in general in the last 4 months. |
| ∘ Have received no spinal manipulation in the last month. |
| ∘ Take no other pain medication than paracetamol, NSAIDs or weak synthetic opioids |
| ∘ Have no competing diagnoses which could |
| (a) confound the diagnosis of nsLBP e.g., osteoporosis, cancer, fibromyalgia etc. |
| (b) interfere with the allocated treatment |
|
Participants were excluded during the study if they: |
| ∘ Were not completing the allocated intervention (minimum 75% of scheduled treatments). |
| ∘ Did not fill out the questionnaires |
| ∘ Received other treatment than that administered as part of the study. |
| ∘ Deviated from the agreed upon medication at baseline measures within the treatment period. |
| ∘ Were unable to hold breath for 10 s. |
