From the second or third trimester on, a simple walk or lifting your leg to climb stairs can become an ordeal. This sensation of sharp stretching in the lower abdomen, these twinges in the groin, or the feeling that the pelvis is "widening" has a name: Lacomme syndrome (or symphysis pubis dysfunction).

Although it is a common physiological process, this discomfort stems directly from the mechanical stress placed on the skeleton. Here are the anatomical explanations and ergonomic solutions to regain mobility in your daily life.

Why does the pelvis become unstable in the 3rd trimester?

Under the influence of a hormone secreted during pregnancy, relaxin, the pelvic ligaments soften to prepare the pelvis for the baby's passage. This increased mobility is essential, but it decreases the natural rigidity of key joints: the pubic symphysis at the front and the sacroiliac joints at the back.

At the same time, abdominal volume shifts the center of gravity forward. This shift causes continuous tension on:

• The round ligaments connecting the uterus to the pubis,
• The anterior joint of the pubic symphysis,
• The adductor muscles on the inside of the thighs, which are recruited to compensate for the instability.

With every asymmetrical movement (walking, stepping onto a curb, getting out of a car), a shearing effect occurs, causing characteristic sharp pains in the groin.

Medical belts vs. technical textiles: what is the difference?

Faced with this ligament pain, healthcare professionals often recommend rigid pelvic belts. Their effectiveness is based on a validated biomechanical principle: applying horizontal circular compression around the hips to lock the sacroiliac joints and prevent the pubis from widening excessively.

While these medical devices are very effective during acute flare-ups, their rigidity can be restrictive when sitting for long periods. This is where textile engineering offers a comfortable alternative:

• Active pelvic bracing: by using high-density knit (320 GSM) around the hips, technical leggings recreate continuous circumferential tension that stabilizes the pelvis without the rigid corset effect.
• Sub-abdominal support arch: an anatomical panel supports the lower uterus to reduce the forward overhang and relieve constant tension on the round ligaments.
• Zero digestive compression: the upper waistband remains fluid to compress neither the stomach nor the diaphragm, avoiding reflux and respiratory discomfort.

3 daily habits to protect your pubic symphysis

In addition to proper support, these simple postural adjustments limit asymmetrical joint widening:

1. Keep legs parallel: To get out of a car or bed, pivot your torso and knees as a single unit, with feet together on the floor, without opening one leg before the other.
2. Sleep with an ergonomic pillow: Placed between the knees and ankles while lying on your side, a wedge keeps the femur in perfect alignment with the hip and eliminates nocturnal twisting of the sacrum.
3. Sit down to get dressed: Put on pants, shoes, and socks while sitting on a stable chair to eliminate painful single-leg standing.

Lacomme syndrome reflects excess weight on softened joints. Providing structural support to the pelvis and relieving the weight of the abdomen helps preserve mobility until full term.