Graded Motor Imagery for Primary Dysmenorrhea

The intervention will be a structured 6-week graded motor imagery program focused on the modulation of pain processing and sensorimotor representation in women with primary dysmenorrhea. It will consist of three sequential steps. Firstly, laterality recognition training with pelvic and abdominal body images. Secondly, explicit motor imagery with pain-free abdominal and pelvic movements. Finally, mirror therapy/visual feedback for normal pain-free movement. The program will be delivered online by a trained physiotherapist with two supervised sessions per week as well as daily home practice. This intervention is different from usual exercise or education because it mainly focuses on the cortical and sensorimotor mechanisms rather than only physical conditioning.

The intervention will be a sham 6-week graded motor imagery program in which the participants will undergo a program of the same amount of contact time as well as duration over 6 weeks with the same number of sessions. The sham intervention will consist of three phases. Sham laterality discrimination tasks will be performed with distal body parts only (e.g., hands and feet) and without pelvic content. Moreover, the sham general relaxation imagery will have peaceful scenes rather than body movement. Lastly, sham mirror exposure will be done by looking at a mirror showing the contralateral hand but not at the pelvic area. The sham protocol aims to control non-specific effects of therapist contact, attention, and imagery engagement, and to remove the pelvic-specific cortical engagement as occurred in the active component of GMI.