The effect of Hatha Yoga on pain intensity in severe primary dysmenorrhea among students: A randomized controlled trials

Background : Yoga has been known as an alternative therapeutic modality for reducing pain. The beneﬁts of yoga for reducing pain have been proven. Women often suﬀer pain due to dysmenorrhea. The eﬀect of Yoga on dysmenorrhea pain has not been widely studied Objectives : This study aimed to investigate the eﬀect of hatha yoga on pain in primary dysmenorrhea (PD). Methods : This was a randomized controlled study (RCT) involving 50 female students, 25

INTRODUCTION each in control (C) and yoga group (Y). PD was diagnosed by Working ability, Location, Intensity (Wong-Baker scale), and Days of the Pain of Dysmenorrhea (WaLIDD) questionnaire. Pain intensity was assessed by the Numeric Rating Scale (NRS). Hatha yoga training was conducted for 12 weeks. The unpaired t-test, ANOVA and Tukey post hoc, and Pearson correlation test was applied. Significance was set at p<0.05. Results: The characteristics between groups were not different. ANOVA indicated the NRS score in control was not changed, while yoga was diminished (p=0.02). Tukey post hoc showed that the second and third NRS were lower than basal NRS (p=0.038 and 0.01, respectively). The third was also lower than the second NRS (p=0.039). The second and the third NRS in yoga were lower than in control (p=0. 027 January 29, 2023 Article revised on February 27, 2023 Article received on March 30, 2023 Dysmenorrhea is highly prevalent with a wide range of prevalence. It is estimated that the prevalence varies from 45% to 95% (1).The prevalence of dysmenorrhea among schoolgirls was about 43%-91%, as reported by previous studies (2). A study in Indonesia reported that about 87.5% of women in Jakarta had dysmenorrhea (3). This wide range might be due to different definitions of the dysmenorrhea condition (1).
A typical symptom of dysmenorrhea is a b d o m i n a l p a i n b e f o r e a n d d u r i n g menstruation (4). However, the symptoms of dysmenorrhea vary across time and between individuals due to various influencing factors (5). Dysmenorrhea symptoms often harm w o m e n ' s d a i l y a c t i v i t i e s . P r i m a r y dysmenorrhea often causes physical activity restriction and increases absenteeism from work and school (5). In more severe symptoms, anxiety, and depression, could arise (6). While the treatment of PD may not get appropriate attention as PD may not be seen as a legitimate health issue by women and healthcare providers (5). Pharmacokinetic treatment is the most common option for dysmenorrhea. Pharmacokinetics drugs aim to relieve pain or symptoms by altering the physiologic mechanisms causing pain and symptoms (7). Drugs such as NSAIDs reduce pain by inhibiting prostaglandin production by decreasing the activity of cyclo-oxygenase  (7), whereas oral contraceptive reduces pain by inhibiting ovulation (8).
However, some women may be unresponsive to NSAIDs, and pharmacokinetic drugs can have some adverse effects (9).
A l t e r n a t i v e t r e a t m e n t s f o r dysmenorrhea have been studied. Yoga is an increasingly popular alternative medicine. A previous study reported that specially designed poses of yoga effectively improved pain and quality of life in non-athlete women aged 18-22 with PD (10). Hatha yoga, with s o m e p o s e s s u c h a s b h u j a n g s a n a , shavasana, and vajrasana, was also claimed to improve pain due to dysmenorrhea (11).  Participants who exercised regularly for at least three months before the study were also excluded. Participants were asked to refrain from taking analgesics at least three days prior to pain evaluation. Also, participants had to discontinue hormonal medication and hormonal status-affecting drugs at least a month before and during the study.
Dysmenorrhea was evaluated using a scale-type questionnaire consisting of four items: working ability, location, intensity (Wong-Baker scale), and days of the pain of dysmenorrhea (WaLIDD). The WaLIDD score is a valid, reliable new tool to diagnose PD (12). Each item provided a score ranging from 0-3; thus, the total score ranged from 0 to 12.
The WaLIDD score was classified as no dysmenorrhea for a score of 0, mild dysmenorrhea for a score of 1 to 4, moderate dysmenorrhea for a score of 5 to 7, and severe dysmenorrhea for a score of 8 to 12.
The Wong-Baker scale is a four scale that describes the intensity of the pain (no hurt, little bit hurts, hurts even more, and hurst worst) (2,12). WaLIDD score was taken once during the first month's menstrual cycle. A score ≥8 was included in this study. .

RESULTS
The characteristics of the participants are described in   The p-value of the correlation is presented in Table 4.     Konasana train thigh and pelvic muscles (25,26). We assumed the above poses could stretch the muscles, increasing muscle flexibility and strength. Muscle cramps around the pelvis are thought to be related to pain in PD (27). Therefore, performing yoga poses as above will train pelvic muscles to increase flexibility and strength, release spasms, and reduce pain in PD.
Many factors are associated with dysmenorrhea. Age, BMI, and age at menarche had been believed as associated risk factors for dysmenorrhea (25,28,29).
However, the correlation between the associated risk factors with pain in PD lacks evidence. A study on the relationship between pain and age has been investigated, but it observed chronic pain in orofacial disorder (30). The association between BMI and chronic pain has also been confirmed (31). To our knowledge, the association between Age, BMI, and acute pain, especially in PD, is less evident. Despite many studies on the relationship between menarche's age and dysmenorrhea, pain intensity predictors have yet to be much explored and reported. A study on pain intensity in PD and its predictors has been performed (32). They found some predictors of pain but did not find the age of menarche to be a predictor of pain (32). Our finding also confirmed no correlation between age, BMI, and age of menarche and pain intensity.
This study had several limitations. Many factors are associated with dysmenorrhea. Age, BMI, and age at menarche had been believed as associated risk factors for dysmenorrhea (25,28,29).

Symptoms of PD and the benefits of
However, the correlation between the associated risk factors with pain in PD lacks evidence. A study on the relationship between pain and age has been investigated, but it observed chronic pain in orofacial disorder (30). The association between BMI and chronic pain has also been confirmed (31). To our knowledge, the association between Age, BMI, and acute pain, especially in PD, is less evident. Despite many studies on the relationship between menarche's age and dysmenorrhea, pain intensity predictors have yet to be much explored and reported. A study on pain intensity in PD and its predictors has been performed (32). They found some predictors of pain but did not find the age of menarche to be a predictor of pain (32). Our finding also confirmed no correlation between age, BMI, and age of menarche and pain intensity.
This study had several limitations.