Lateral Diastasis and diastasis recti
Lateral diastasis is infrequent and generally occurs in association with other systemic pathologies that weaken the collagens. It does not occur in isolation and is almost always preceded by failure of the linea alba then classic diastasis recti (rectus abdominis diastasis).
It may happen that some patients with simple diastasis recti (rectus abdominis diastasis), seeing the loss of waistline that it entails, self-convince themselves (partly due to unreliable information found online) that they have lateral diastasis although clinically they have no defect at the right-oblique junction.
In fact, a characteristic sign of classic diastasis recti postpregnancy is the loss of the waist, the hips become straight, and the patient suffers some aesthetic penalization , but the defect is uniquely central and affects only the linea alba.
Lateral diastasis is uncommon and is not typical of postpregnancy
The occurrence of lateral diastasis in the context of a postpregnancy diastasis recti is at least unlikely, we will see below why.
The two rectus muscles are anchored laterally to the obliques by a very strong tendinous tripartition while they are joined together in the middle by a single tendon, the linea alba.
The linea alba in relation to the three lateral tendons is itself more fragile and suffers more from the increase in volume in pregnancy because more forces are discharged on it in orthostatism and during movements.
Therefore, the pathophysiology leading to the formation of diastasis recti acts first on the"locus minoris resistenzieae"i.e., the linea alba than on the lateral regions of the abdominal wall.
In almost all cases, the tendon injury present in a postpregnancy diastasis affects only linea alba (which is the first to fail) and not the junction between rectus and obliques.
By reconstructing the midline of the abdomen, the lateral component is also emphasized by receiving the proper tension, thus a narrower and more visible waistline is defined.
Lateral diastasis is generally associated with other systemic pathologies
As we have seen the development of lateral diastasis, vis-à-vis natural events (such as pregnancy), is unlikely to say the least.
It possibly remains possible in the context of some systemic (often hereditary) pathologies affecting collagens, and in that case it is associated with other, far more noteworthy pathologies that precede it in the patient's clinical priorities.