Patients lay down on a prone position, with their hands around the body and neck placed comfortable. The therapist performed a postero-anterior joint mobilization using Maitland's technique, applying pressure to spinous process of targeted vertebra (the one who reproduces patient's symptoms).

Patients perform their painful movement (flexion, extension…). If pain wasn't reproduced, a combination of movements will be performed (flexion + rotation…). The most painful vertebral level was assessed too with passive accessory vertebral movements. Afterwards, with the patient on a seated position on a stretcher with feet supported and a belt around the waist, the therapist performed a sustained glide on the targeted vertebra (spinous process) with the force and direction that relieved pain to the lowest level.

Patients were measured at baseline and then were placed on "wait list" until the end of the study. At this time, they were measured again.

Dosage: 5 sets of 2 minutes with 30 seconds of rest were applied, with a strong force (>50% of maximum therapist strength), according to patient's irritability and severity.

Visual Analogue Scale (VAS) was used to measure pain. It consists of a 100mm length line and has written "no pain" and "worst pain imaginable" on its ends and measures pain intensity. The confidence and reliability of this scale has been approved and validated in different studies.

A digital algometer was used to measure mechanical hyperalgesia. The model was de X® brand, consisting of a 1cm2 cylindrical rubber attached to a pressure gauge, calibrated in kilograms (kg). The scale expressed in kg/cm2 was used. Before the measurement, patients were trained in forearm muscles through a trial session. They were instructed to say STOP when the pressure sensation was painful. For the measurement, patients lay down on prone position on the stretcher and the algometer was placed perpendicular to skin on the measured points, who were marked prior to measurement (2cm lateral to L5 spinous process, C2 spinous process, ipsilateral anterior tibialis and contralateral epicondyle). A rest period of 30 seconds was established between the measurements. For each point, three measurements were done and their mean was calculated and recorded for analysis. The minimum detectable change (CMD) for considering the results as clinically relevant was established at 15% minimum.

Temporal summation was measured with Von Frey monofilaments. Patients lay down on prone position and measurements were taken 1cm lateral to spinous process of L4. First, a single stimulus was applied and the patient assessed the pain intensity on a 0-10 numeric rating scale. After that, 10 rhythmic stimuli were applied on the same spot (1 stimuli per second) and the patient assessed again the pain intensity. The temporal summation effect was calculated as the difference between the mean rating of the three repetitions of one stimulus and the mean rating of the three repetitions of 10 stimulus.

Catastrophism was measured with Spanish version of Pain Catastrophizing Scale. It's a 13-item self-report measure of catastrophizing and it's constructs as rumination, magnification and helplessness. It must be answered by numeric values between 0 (not at all) and 4 (all the time), with a maximum score of 52 points. The minimal detectable change was identified at 9.1 points.