Your core is often thought of as just the outer abdominals, but should be thought of more as a cylinder. On the front is the deep abdominals (transverse abdominis), on the back is the small back stabilizing muscles (multifidi), the top is the diaphragm, and the bottom is the pelvic floor.
Often there is an imbalance of pressures in the core which causes increased abdominal pressures forward or increased pressure downward on the pelvic floor and pelvic organs.
This imbalance can worsen or prevent healing of a diastasis recti (separation of the abdominal muscles and linea alba). It can also cause pelvic floor dysfunctions leading to urinary incontinence, increased urinary urgency and frequency, constipation and pelvic organ prolapse including cystoceles, urethroceles, uterine prolapse, and rectocele.
A hypopressive exercise uses postural and breathing techniques to create an abdominal vacuum which takes pressure off of the abdominal fascia (linea alba), pelvic organs and pelvic floor.
The downward pressure is reversed into an upward pressure by drawing the diaphragm up towards the head during a breath holding technique. The pelvic floor and lower abdominals (transversus abdominis) will automatically contract, helping to strengthen the deep core muscles. These muscles can also be encouraged to contract more during the exercise for maximum strengthening and support.
The hypopressive exercises are performed in different postural poses and movements to utilize the small stabilizing muscles throughout the body to encourage better diaphragm, rib cage, and accessory muscle length and stability of the spine.
It is also theorized, that the upward suction created during the hypopressive exercise also can help break up restrictions in fascia throughout the abdominal cavity around the bowels and the pelvic cavity around the pelvic organs.