Although it is already well known that breast milk is the most ideal source of nutrition for the health of babies' bodies and minds, many mothers discontinue breastfeeding. Recently in Korea, there has been interested in and campaigns encouraging breastfeeding, but according to statistical data that consider breastfeeding to be exclusive breastfeeding only as well as combining breast milk and baby food, the breastfeeding rate in Korea was 59% in 1985, 11.4% in 1994, 14.1% in 1997, 10.2% in 2000, 16.5% in 2003, and 24.2% in 2006 (Korea Institute for Human and Social Affairs [KIHASA], 2008). These rates are very low compared to the figures reported by the United States National Center for Health Statistics (McDowell, Wang, & Kennedy-Stephenson, 2008), which were 60% in 1994, 64% in 1998, 67% in 2000, 70% in 2004, and 77% in 2006.

Recently, many non-governmental organizations, UNICEF, and the Korean Nurses Association have shown great interest in breastfeeding, campaigning actively to promote it; however, the rate of breastfeeding, including combined feeding, has remained low, at 24.2% (KIHASA, 2008). The results from a study showed a large drop in the breastfeeding rate, from 61.7% at 1 month to 26.0% at 2 months (Yeo & Hong, 2003). Studies on the current state of breastfeeding and breastfeeding discontinuation have revealed that lactation disturbances during the initial phase were caused by physical fatigue, the lack of breast milk, problems in managing the nipple and breast, and babies' breastfeeding difficulties (Eum, Sohn, & Kim, 2007). The difficulties faced by subjects who practiced breastfeeding 1 week after delivery were the lack of breast milk, nipple fissures, inverted nipples, and so on (Yoo, Kim, & Seo, 2002), leading to the conclusion that the amount of breast milk and the management of the nipple and breast continue to be problems.

In Korea, various educations for breastfeeding are provided as nursing interventions for the purpose of promoting breastfeeding. For the purpose of increasing the low breastfeeding rate, the factors affecting breastfeeding and the effects of nursing interventions have been previously examined. Among the measures that have been implemented to promote breastfeeding, improving knowledge (Sung & Kim, 2003), boosting confidence (Suh & Lee, 1998), conducting breastfeeding education and follow-up care (Park & Koh, 2001), conducting breastfeeding management programs (Choi & Kim, 2007), following up via telephone, and practicing rooming-in (Wang & Kim, 2009) have been effective in increasing the rate of breastfeeding continuation when implemented. However, there was no significant difference 2 weeks after delivery between the breastfeeding rates of the experimental group, supplemented with a breastfeeding management program or telephone follow-up, and the control group, whereas there was a significant difference 4 weeks after delivery (Choi & Kim, 2007). From these results, one can infer that other measures for managing breastfeeding, in addition to education and management, are needed 2 weeks after delivery (Choi & Kim, 2007). Lee also emphasized the necessity of breast nursing care that is focused on the lactation phase and of effective and proactive nursing interventions, along with in-depth education (Lee, 1999). In particular, after systematically examining the effects of various measures for treating blood congestion during breastfeeding, it was concluded that there was not sufficient scientific evidence that ultrasonic waves and cabbage leaves alleviated blood congestion in the breast (Mangesi & Dowswell, 2010).

As another intervention method, Oketani breast massage developed by Oketani, is painless and separates the retromammary space, which is the connective tissue between the breast and the greater pectoral muscle (Oketani, 1991a). Oketani breast massage is also known to promote the secretion of milk, to alleviate an inverted nipple or papilla plana, and to relieve blood congestion in the breast as well as breast pain. Additionally, it is very effective in increasing breast milk pH (potential of hydrogen), in increasing sweet taste of breast milk and in stimulating the growth and development of the infant (Oketani, 1991a).

The pH of cow's milk or breast milk can differ depending on the type of milk. In general., the pH of fresh milk is mildly acidic, and the pH of fresh human milk is mildly alkaline. The pH of the colostrum started high at 7.45, dropped to 7.04 after 2 weeks of breastfeeding, stayed between 7.0 and 7.1 over the next three months, and became high again at 7.4; this finding was thought to be due to changes in the composition of breast milk (Morris et al., 1986). However, Harrison and Peat (1972) reported that the breast milk pH was 7.29, on average, ranging between 6.80 and 7.70. Nonetheless, breast milk pH lacks scientific data and has not been sufficiently studied. Although there have been no studies confirming the effects of breast massage on breast milk pH, Oketani has stated that, when there is a disturbance of blood and lymph circulation within the breast, the quality of breast milk deteriorates, producing oxidised milk that does not taste sweet at all but rather tastes sour or salty and is highly viscous and hazy (Oketani, 1991a). However, when blood circulation is improved, better quality milk with a higher pH is produced, which aids in the growth and development of the infant (Oketani, 1991b). But previous studies didn't give sufficient evidence the effects of Oketani's massage on breast pain reduction. Moreover, it is rare to find the effects of Oketani's massage on breast milk pH or sucking speed of neonates. There was no scientific evidence that substantiated that Oketani breast massage had an impact on breast milk pH, and the only finding reported was that the concentration and the total energy of lipids and casein were affected (Foda, Kawashima, Nakamura, Kobayashi, & Oku, 2004). It was also reported that Oketani breast massage reduced the pressure within the breast by eliminating blood congestion and increased breast milk pH, resulting in better tasting breast milk and the tendency of babies to attempt to suck better.

In summary, Oketani breast massage has been suggested to alleviate breast pain and increase breast milk pH, improving the taste of breast milk and producing faster sucking speed and the enhanced growth and development of infants; however, scientific evidence corroborating the effects of breastfeeding using Oketani breast massage is insufficient.

Thus, this study attempted to elucidate the effects of Oketani breast massage on breastfeeding compared with conventional massage. In other words, it attempted to assess pain due to blood congestion in the breast as it impacts the mother by comparing pain before and after treatment. It also attempted to verify the effects of Oketani breast message by investigating the quality of breast milk via breast milk pH and the sucking speed of neonates.

The purpose of this study was to test the effects of Oketani breast massage on breast pain, breast milk pH, and the sucking speed of neonates in the experimental group that received Oketani breast massage and in the control group that received conventional massage.

This study attempted to test the effects that Oketani breast massage has on breastfeeding as a method for relieving breast pain. While the control group received conventional breast massage, the experimental group received Oketani breast massage, and the resulting effects on breast pain, breast milk pH, and the sucking speed of neonates were comparatively analysed.

Postpartum breast pain is a problem that occurs frequently in mothers, but health care providers are not very proactive in its management. Thus, it has been reported that many mothers discontinue breastfeeding because of a lack of breast milk (Lee, 2001) or problems of the breast (Park, 2001). Mothers relieve breast pain using the popular methods of hot pack and breast massage, but many mothers continue to suffer from severe pain.

The study results showed that breast pain was significantly relieved in the experimental group that received Oketani breast massage compared to the control group. After the experimental treatment, breast pain was reduced by 5.14 in the experimental group and by 0.92 in the control group, indicating that breast pain was very significantly relieved in the experimental group. This small amount of breast pain relief in the control group appears to be a natural result of the decrease in the amount of breast milk following breastfeeding. However, because the breast pain relief in the experimental group was very significant compared with the control group, it can be concluded that Oketani breast massage is very effective in alleviating breast pain. This result is similar to studies that have reported that Oketani breast massage relieved breast pain during the initial phase of puerperium (Konish, Yoshidome, Miyazaki, & Kumashiro, 2004). These results also support a study that claimed that Oketani breast massage was a painless breast-massaging method that softens the entire breast (Foda et al., 2004).

The breast milk pH increased by 0.25 in the experimental group and by 0.03 in the control group after the experimental treatment, indicating that breast milk pH in the experimental group increased significantly. In the past, studies on breast milk pH were insufficient and were mostly conducted by measuring pH, and more studies existed on the pH of cow's milk than that of breast milk. The results of one study measuring breast milk ph (Harrison & Peat, 1972) found that when breast milk was collected before breastfeeding 1 week after delivery, the breast milk pH ranged from 6.80 to 7.70, and the mean was 7.29. The results of another study found that the pH of colostrum was high, at 7.45, but the pH was 7.04 during the second week of breastfeeding (Morriss et al., 1986). Considering the results of those previous studies, the results of this study can be considered average because the breast milk pH values for the experimental group and the control group were 7.16 and 7.10, respectively, before the experimental treatment. However, in our study, after the experimental treatment, the breast milk pH of the experimental group was 7.41, which was similar to the pH of colostrum or that of breast milk after two weeks. However, although the difference in breast milk pH between the experimental group and the control group was statistically significant, there was a limitation in explaining the difference in the taste of the milk with different pH values. Oketani (1991a) stated that the taste of milk was determined by changes in the quality of the milk within the breast, i.e., milk with a pH of greater than 7 was of a higher quality. In our study, the pH was greater than 7.0 for both the experimental group and the control group before and after the experimental treatment, which means that both groups were at the normal level based on Oketani's standards provided above. While conducting this study, milk tasting as an organic indicator was attempted, with the goal of examining differences in the milk, but no scientific conclusion could be reached. Moreover, as this study did not analyse the composition of the milk, it is necessary to study the differences in milk composition in the future. In addition, because no recent study was found to corroborate the study by Harrison and Peat (Harrison & Peat, 1972), which stated that the pH of milk is important for growth and development, there is also a need for a follow-up study on this issue in the future. The results of this study are similar to those of Kobayasi (1991) who reported that with powdered formula, the pH did not differ from the beginning to the end of bottle feeding, while in cases in which a mother breastfed a neonate, breast milk pH increased from 7.2 at the beginning to 7.4 at the end of breastfeeding, resulting in the breast milk becoming alkalised and tasting better.

Furthermore, the sucking speed of neonates increased by 18 times/minute in the experimental group and by only 1 time/minute in the control group after the experimental treatment, indicating that the increase was more significant in the experimental group than in the control group. Park (2004) reported that instances of clumsy suckling, e.g., when the neonate's suckling power was weak, when the neonate did not feed eagerly, and when the neonate fed too eagerly, caused many mothers to give up breastfeeding. From this finding, one can infer that the condition of the breast and the baby's suckling are very closely related. This relationship supports the principle that the neonate's degree of suckling, i.e., suckling power and rhythm, and the suckling conditions are enhanced when Oketani breast massage is used to induce an increase in the amount of breast milk as well as to improve the stretching of the areola and the condition of the breast (Oketani, 1991a, 1991b). According to a study that evaluated breastfeeding rate depending on the extensibility of the nipple and areola (Joo, 2008), the favourable group with extensible nipple and areola, displayed higher breastfeeding rates after childbirth compared to the other group. Thus, it appears that improvements in the extensibility of the nipple and areola, fostered by breast massage, affect the suckling process of neonates positively, resulting in a higher suckling speed.

Oketani breast massage was very effective in alleviating breast pain and increasing breast milk pH and the sucking speed of neonates. Oketani breast massage could be utilized as an independent nursing intervention method.

We suggest that the repeated experimental study is needed to find the evidence of Oketani breast massage on the growth and development of babies and on a higher continuance rate of breastfeeding in the future.