For proper alignment, I want you to work hard during exercise to think about ribcage over hips. This means that your ribcage is stacked over your pelvis in order to create alignment that is safe for your postpartum body. When the ribcage is over the pelvis, the diaphragm is stacked over the pelvic floor, and this creates a solid core canister.
During normal daily movement however, it is beneficial to your body to be in a variety of positions that feel supported and comfortable. It wouldn't be natural to stay perfectly stacked all day. However, during normal daily movements that involve heavy lifting (like carseats and strollers and babies) it is a good thing to keep this alignment (and exhale on exertion breath) in mind.
By keeping your body stacked you are reducing intra-abdominal pressure. This pressure puts stress on the pelvic floor and can worsen diastasis recti, so we want to avoid it. Heavy lifts without good alignment create intra-abdominal pressure, as do sit ups, planks, push ups, jumping - so many things. Intra-abdominal pressure is not BAD - some is necessary to support the spine - but too much of it is just not ideal for healing and keeping the pelvic floor safe.
It's also important to focus on good alignment when holding babies and breastfeeding since we often do these things many hours of the day. We often will hold a baby on one hip or stand with our bum tucked or ribs flared out. These positions are not ideal because they take the body out of alignment. See the video below for more on alignment!
Every exercise should be done with good inhales and exhales and proper alignment. This is what makes these exercises effective in creating a stronger core and pelvic floor.