The patients were positioned in supine with adjustable lumbar, and thoracic belts attached to the traction cord. After tightening the belts, the M7 position was selected to achieve hip and knee flexion, and posterior pelvic tilt of 25° was added. Before starting the therapy, the weight of the subject was entered in the panel, and a short tolerance test was carried out. Patients were provided with a manual switch to stop treatment any time. Preset lumbar disc herniation protocol was used. Each session lasted fifteen minutes, applied force had 100-gram step increments, and did not exceed 50% of the weight of the patient. At the end of the therapy, the cord was disconnected and belts were removed. Participants were asked to sit for three minutes to identify any adverse reaction.

The patients were positioned in supine with adjustable lumbar, and thoracic belts attached to the traction cord. After tightening the belts, the M7 position was selected to achieve hip and knee flexion, and posterior pelvic tilt of 25° was added. Before starting the therapy, the weight of the subject was entered in the panel, and a short tolerance test was carried out. Patients were provided with a manual switch to stop treatment any time. Preset lumbar disc herniation protocol was used. Each session lasted fifteen minutes, applied force had 100-gram step increments, and did not exceed 50% of the weight of the patient. At the end of the therapy, the cord was disconnected and belts were removed. Participants were asked to sit for three minutes to identify any adverse reaction.

We measured self-reported disability associated with spine disorders through the spanish version of the Oswestry Disability Index (ODI), a reliable and validated instrument composed by ten sections (pain intensity, personal care, lifting, walking, sitting, standing, sleeping, sex life, social life and traveling), in which the patient grades the disability from zero (no limitation) to five (limitation prevents me from performing the activity). The ODI final score was calculated with the following formula: [total score/(5 x number of answered questions)] x 100%, and interpreted as the higher the score, the greater the disability.

Pain intensity was also evaluated with the numeric pain rating scale (NPRS), a popular clinical tool consisting of a numbered straight line from zero (no pain) to ten (the worst pain), where the patients registered their current pain intensity.