Immediate effect of a global pelvic manipulation technique on lumbar pain in patients with primary dysmenorrhea: a randomized controlled trial

INTERVENTION: The experimental group will receive a global pelvic manipulation (gpm) technique. The patient will lie in lateral position. The therapist stands in front of the patient. The therapist will then flex the top leg until there is movement at the selected segment interspace (L5 fifth lumbar vertebrae ‐S1 first sacral segment) and place the patient's foot in the popliteal fossa of the bottom leg. Next the therapist grasps the patient's bottom shoulder and arm and introduces left trunk sidebending and right rotation until motion is felt at the selected interspace. This interspace will be controlled by therapist's both hands adding a small traction. Finally the therapist will apply a high velocity, low amplitude thrust of the pelvis in an anterior direction. the whole technique lasts for two minutes and will be performed just once. The technique is harmless and painless CONDITION: Pressure pain treshold in sacroiliac joints Self‐perceived pain in lumbo‐pelvic area PRIMARY OUTCOME: ‐ To quantitatively assess the effect of global pelvic manipulation (GPM) on lumbo‐pelvic self‐perceived pain using VAS scores. SECONDARY OUTCOME: ‐ To assess body's endogenous response to pain following a catecholamine and serotonin release. A blood test will be done to measure the catecholamine / serotonin levels with an expected variability of 15% ‐ To explore differences in Pressure pain threshold (PPT) in sacroiliac joints (SIJ) with an algometer (FXP 25, Wagner Instruments), predicting an improvent in mechanosensibility in at least a 10% INCLUSION CRITERIA: (i) age between 18 and 60 years old (ii) regular menstruation intervals (iii) willing to participate in the study