Various phenomena are related to this:
The volume of the uterus increases and, as a result, the ligaments supporting the uterus in the pelvis are stretched. Pregnant women may experience pain in the lower abdomen and legs.
During pregnancy, hormones are also responsible for a physiological change. Relaxin is a hormone that promotes the relaxation of connective tissue, ligaments and tendons, to assist in vaginal delivery, but this leads to instability of pelvic statics.
The centre of gravity shifts forward as the weight of the uterus and breasts increases.
The muscles of the back must constantly work to rebalance the pelvis, hence the contractures of the back muscles and pain. The back and abdominal muscles are antagonistic. But they are also complementary to support the trunk, hence the importance of a balance between the two.
The mechanical stresses on the musculoskeletal system of load-bearing joints such as the lumbar spine, lumbosacral joint, sacroiliac joints and pubic symphysis lead to a range of pain that can be improved by using the cushion.
Pregnant women are at risk of circulatory problems during pregnancy. The weight of the uterus compresses the inferior vena cava, which drains blood from the legs to the heart. This leads to retention and can even lead to the formation of varicose veins and haemorrhoids, especially if you are sedentary. The support of the ischiums in the sitting position leads to less vascularisation since the veins and vessels pass through there.
The perineum is put under severe strain during pregnancy. The uterus and the weight of the baby press strongly on the perineum, the real floor that holds the viscera. It weakens and relaxes from the 12th week. It is important to strengthen it.
Why sit on the cushion?
A first interest lies in the improvement of posture. In order to improve the statics of the spine, in the sitting position, one should exercise an upward self-growth by avoiding leaning against the backrest. The cushion reactivates the erectile muscles of the spine and allows a natural posture with improvement of the three curves of the spine.
An additional benefit of sitting on the cushion: you're gently working out! Strengthening deep muscles such as the transverse is possible thanks to the cushion. The imperceptible instability and automatic correction of our posture on the cushion makes our deep abdominal muscles work without feeling it.
An additional interest of the cushion is in the perineum. The shape and dynamics of the cushion help the pregnant woman to feel her perineum better and to strengthen it. It reduces the pressure on this muscle which allows a better vascularization, a better freedom of movement in order to contract it but also helps to relax it at the time of childbirth. In immediate post partum, it allows the pelvic floor to rest due to its cut-out shape which prevents pressure on a possible episiotomy or temporary sensitivity related to childbirth.
It is therefore an ally of the pregnant woman for comfort during her pregnancy but also in immediate post partum and afterwards. It improves blood circulation by reducing pressure on the pelvic floor and by the imperceptible movements of the pelvis. The cushion makes the junction between the asymmetry of the body, sometimes increased by pregnancy-related ligament instability, and the symmetry of the furniture. Adopting the cushion throughout the day will help the pregnant woman to live her pregnancy more serenely as well as the post-pregnancy period.