Birth Is Biomechanical — Not Just Hormonal (Here’s Why That Matters)

Birth is a biomechanical event.

Yes, it’s hormonal. Yes, it’s spiritual. Yes, it’s mysterious and holy and more than we can ever fully understand.
But it is also, fundamentally, the movement of tissue — both bony and soft — from the inside of the maternal body to the outside.

That movement isn’t random. It isn’t purely hormonal.
It’s biomechanical. And if we want to support more effective, functional, and easeful births, we need to understand what that really means.

What Are We Really Talking About When We Say “Biomechanics”?

Biomechanics refers to how tissues — muscles, fascia, bones, and joints — move and interact within living, adapting systems.

In the context of birth, it’s about:

• The movement of the baby through the maternal pelvis

• The shape and mobility of the pelvic bones

• The yield, strength, and adaptability of the soft tissues

• The functional coordination of the mother’s body in creating space for descent

This isn’t theoretical. It’s observable. It’s functional.
And it determines whether or not a baby is able to navigate the birth canal with ease.

Hormones Help — But They’re Not the Main Event

We’ve all heard the narrative: oxytocin, endorphins, the hormonal cascade.
But here’s the reframe: hormones support tissue movement — they don’t drive it.

The role of the hormonal blueprint is to change the shape of the tissues.
Prostaglandins, relaxin, decreasing progesterone, and rising oxytocin are all working to soften, yield, and mobilize the body.

But if the body is lacking mobility, blood flow, or fascial adaptability, hormones alone won’t get the job done.
Their role is to enable the biomechanical process — not override it.

So when we focus solely on preserving the hormonal unfolding but ignore the condition of the tissues themselves, we’ve missed the point.
Tissue mobility is the foundation. That’s what birth actually requires.

What Birth Hormones Do:

• Increase softness and flexibility in tissues

• Create uterine tone and contractility

• Shift tension patterns in smooth muscle and fascia

A well-functioning hormonal cascade in a restricted pelvis still leads to dysfunction.
A compromised hormonal state can still result in functional birth — if the biomechanics are sound.

This is why I teach: biomechanics before hormones.

How the Pelvis Actually Works During Birth

To be born, a baby moves through three distinct anatomical levels of the pelvis:

1. Pelvic Inlet

• The entry point into the pelvis

• Widest dimension is posterior, not near the pubic bone

• Baby needs to be angled toward that posterior space

• Influenced by maternal abdominal tone, pelvic tilt, and sacral mobility

2. Mid Pelvis

• Where rotation and descent occur

• The space where layers of the pelvic floor insert

• Requires soft tissue yield and posterior fascial mobility

• Restrictions here (SI pain, glute dysfunction, chronic tailbone pain, hip hikes, or difficulty yielding in the posterior pelvic floor) often result in dysfunctional labor patterns

3. Pelvic Outlet

• Final exit point of the pelvis

• Composed of:
  — Bony structures (ischial tuberosities + coccyx), which open with internal femur rotation
  — Soft tissue sphincters, which must stretch and yield

• Movement capacity here is individualized — squatting helps some, but hinging creates more space for others

There is no universal “best position.”
There is only what creates space in your body — and that’s determined by your unique biomechanics.

Babies Aren’t Doing the Work Alone

There’s a confusing narrative that babies are actively squirming and pushing their way through the pelvis.
But I’ll say it clearly: babies are being moved.

They are being shaped, guided, and rotated by:

• The bony structures of the maternal pelvis

• The soft tissues of the pelvic floor

• The dynamic relationship between fascia, breath, and maternal movement

They don’t have head control. They’re not doing this alone.
Babies move where there is space. Full stop.

This Isn’t Just Theory — It Affects Outcomes

I’ve supported births for nearly a decade, and studied female biomechanics for even longer.

And what I’ve seen over and over again is this:

We overemphasize the hormonal and fetal role in birth — and underemphasize the maternal contribution.

• Babies don’t push themselves through the pelvis — they’re moved by the maternal tissues

• Hormones don’t open the pelvis — they enable it

• Labor positions don’t work if the tissues can’t respond or yield

This is where contemporary birth culture needs a serious update.

When we look at birth through a biomechanical lens, we begin to see real patterns in how labor unfolds — and where it doesn’t.

When babies don’t engage, when labors start and stop, or when things feel stuck despite “everything being in place,” it’s often not mystery — it’s structure.

• A baby who can’t angle toward the back of the pelvic inlet may hover for hours without true engagement.

• Lack of mobility or yield in the mid pelvis can prevent rotation or descent.

• If the outlet can’t open — structurally or through the soft tissues — no amount of pushing will be effective.

The maternal tissues shape the fetal path.
Babies position themselves in response to the space available.
They go where there’s room.

So instead of focusing only on “optimal positioning,” I’m more interested in what’s creating those positions in the first place.

This is why understanding maternal biomechanics matters.
It’s not just to “optimize” birth — it’s to work with the actual tissues that are shaping the process from the inside out.

The Problem with Hands-Off Birth Culture

The hands-off model — across all corners of the birth world — has gone too far.

• Obstetrics relies on technology and instruments in place of manual skill

• Midwifery often avoids touch or movement to "let birth be"

• Doulas and birth keepers are trained to support without physically engaging

But birth is physical. Birth is embodied.

If we’re not trained to understand how babies move through the pelvis — and how the pelvis creates or limits that space — then we can’t respond effectively.

Movement techniques only work if tissues can yield.
And tissue yield isn’t conceptual. It’s physical, real, and trainable.

Functional Birth Starts Before Labor

You can’t separate birth from the body that’s birthing.

Physiological birth relies on physiological womanhood.

That includes:

• How we sit, stand, breathe, and walk

• How we’ve moved over the course of our lives

• What kinds of postural patterns or restrictions we carry

• How much space, tone, and mobility our tissues actually have

If your tissues aren’t moving well now, they’re not going to magically move well in labor.

We need to look at:

• Sedentary lifestyle patterns

• Chronic tailbone tucking or gripping

• Hip hikes, fascial tension, and glute inactivity

• Environmental stressors, age, and overall movement history

The conditions that shape your body before birth will shape the birth itself.

Where to Start: Observation, Movement, and Ongoing Learning

If this lens resonates with you — if understanding birth as a tissue-driven, biomechanical process feels like something that’s been missing — there are so many ways to keep going with it.

Start by noticing your own body:

• Where do you feel ease? Where do you feel resistance?

• What movements give you more breath, more softness, more space?

• What happens when you pay attention to your pelvic mobility — not just your flexibility, but your function?

If you support women — whether you're attending births, offering bodywork, or walking alongside mothers in some way — I invite you to start seeing birth through this framework.
Not as something to manage or optimize, but as something to understand.

This is what I’m here for. To offer the tools, language, and practice that have helped me support mothers and birth workers with more clarity, more confidence, and more reverence for what their bodies are actually doing.

If you want to go deeper into this work, my course Born Through Movement is one way to do that — but it’s not the only way.
This framework lives in how we listen, how we observe, how we work with what’s real in the body in front of us. Whether that’s your own, or someone else's.

So start there. Keep asking questions.
Keep learning from the body — because that’s where the answers are.

In devotion,
Adelaide