Hello, Noemí. Menstruation is a broad topic because every woman experiences her period and the days leading up to it differently, and may also experience different “energetic imbalances”.
Generally speaking, we could say that when we are menstruating (let’s say on the first and second days), there is a greater risk of inflammation in the uterus, and we should therefore avoid placing balls on the abdomen. However, the other areas we avoid during pregnancy (feet, hands, shoulders and back) are fine to treat, provided our period is not excessively heavy. These are points that help release blood from the uterus, which is beneficial for promoting menstruation, but some women suffer from menorrhagia or metrorrhagia, and in these cases we should avoid these points as well. Of course, how can we tell if a student is experiencing this? We cannot know unless we practise yoga therapy.
Please also bear in mind that the “therapeutic effect” of the Mioball® technique, just like that of Asanas, lies in consistency and repetition. When offering general Mioball® technique classes, the amount of time spent with the ball is relatively short, as is the frequency of use. The effect on the uterus occurs mainly when the stimulus is consistent over time (for example, when the student practises every day). So, if your student has practised with you once a week, there won’t be much of a problem or disruption to her period. Do you see what I mean?
It’s much the same with premenstrual syndrome. Depending on the woman, some points will be very painful when pressed, whilst others will not. In TCM, premenstrual syndrome can be caused by various types of imbalance. As we do not know what is happening to the woman or which organ is responsible for her imbalance, the only way you can help her is to let her choose the “pi” point herself. Let her decide where to focus and which point she finds most interesting to feel. Ultimately, you are guiding her, just as when we practise asanas, but it is the person herself who must find the right threshold or spot.
I hope this clarifies the matter further. Best regards!