Dysmenorrhea is a menstrual disorder defined by the presence of painful cramps of uterine origin that occur during menstruation. It is one of the most common causes of pelvic pain and short-term absenteeism from school or work, among young and adult women \[1\].
The prevalence of Primary dysmenorrhea is highest in the 16-25-year age group but is greatly underestimated as many women consider pain a normal part of the menstrual cycle and do not seek medical treatment, despite the considerable distress they experience. A previous systematic review on the impact of dysmenorrhea in adolescents reported that the prevalence is high and that it imposes a significant negative impact on academic performance \[2\], restrictions on daily activities and sports or social and sexual relationships \[3\].
Primary dysmenorrhea occurs in the absence of pelvic pathology, it is mediated by elevated prostaglandin and leukotriene levels, inflammation causing uterine contractility and cramping pain. Secondary dysmenorrhea is due to pelvic pathology or a recognized medical condition and accounts for about 10% of cases of dysmenorrhea. The most common etiology of secondary dysmenorrhea is endometriosis, other etiologies include congenital or acquired obstructive and nonobstructive anatomic abnormalities (e.g., müllerian malformations, uterine leiomyomas, adenomyosis), pelvic masses, and infection \[4\].
It has been demonstrated that prostaglandins are overproduced in dysmenorrhea. Prostaglandins cause narrowing of the blood vessels supplying the uterus, abnormal contractile activity of the uterus, which leads to ischemia, hypoxia of the uterus and increased sensitivity of the nerve endings \[5\].
The treatment approach is mainly directed toward relieving the pain through physiological mechanisms that underlie menstrual pain (production of prostaglandins). The treatment is also aimed toward the improvement of the function, leading to fewer days lost at work, school or extracurricular activities \[6\]. There are different approaches to the treatment of primary dysmenorrhea. The drug approach is achieved through prostaglandins inhibitors, which are non-steroidal anti-inflammatory drugs (NSAIDs) and hormonal drugs such as contraceptives. Many NSAIDs which non-specifically inhibit both COX-1 and COX-2 enzymes (e.g., ibuprofen) are the most common initial therapy for dysmenorrhea \[7\]. Likewise, oral contraceptives are not free from side effects either, related as they are to the frequency of bleeding, weight gain, or the patient's basal risk of venous thromboembolism \[1\].
All this shows us that there is a need for emphasis on alternative methods of conservative treatment as a non-pharmacological and non-invasive therapy, safe and easy to use for obtaining relief from dysmenorrhea symptoms, including acupuncture and acupressure, biofeedback, heat treatments, transcutaneous electrical nerve stimulation (TENS), exercises and relaxation techniques \[8\]. On the other hand, these physiotherapeutic treatments, being supported by clinical trial data, could be a very useful treatment alternative for women with primary dysmenorrhea, particularly those who are not eligible for pharmacological therapy, since physiotherapy has no side effects according to the analyzed studies \[9\]. Exercise is an activity performed to develop or maintain fitness which requires physical exertion, is one of the non-pharmacological and effective ways of treating dysmenorrhea. Many reviews have evaluated the efficacy of exercise or individual physiotherapy interventions for primary dysmenorrhea \[10\].
Alternative or non-pharmacological treatments include TENS, exercise, acupuncture, acupressure, massage therapy, heat pads. The reduction of pain maybe due to the effect's hormonal changes in the uterine tissue or due to an increase in the endorphin levels \[11\].
Core muscle strengthening focuses on isolated muscle group conditioning which will strengthen the small intrinsic musculature around the lumbar spine and provide lumbar stability. When these muscles are strong, they become capable of handling normal biomechanical forces even the stress of menstrual cramps which a women's body undergoes during the menstrual cycle (12).
Core stability exercise has been known as a beneficial intervention in the management of several medical problems. Core stability exercises strengthen and coordinate the muscles around the abdominal, lumbar, and pelvic regions. Because it has been suggested that the core stability exercises mainly affect the lumbosacral muscles and increase blood supply in lumbosacral structures.
It was proved in some studies that core stability exercises can improve pain and function for primary dysmenorrhea in young and adult women. (13,14) but the number of studies about this were limited with many limitations so, we hypothesized that the core stability exercises might be effective in reducing primary dysmenorrhea symptoms.
So, this study was designed to compare among the effect