Understanding Hypermobility in Babies: What It Means and How to Support Their Movement

Chloë Robinson
Jul 22
3 min read

If you've ever noticed your baby folding up like a tiny yogi or doing splits with impressive ease, you might have wondered, “Why is my baby super floppy?”. Some babies are naturally more flexible, and that can be totally normal. But if their flexibility seems extreme, it might be something called hypermobility.

So, let’s break down what that means - and how it can affect your baby’s movement as they grow.

What Is Hypermobility?

Hypermobility in babies means that the joints move more than they typically would. Think bendy elbows, extra-stretchy knees, or ankles that seem to wobble quite easily. It’s due to looser connective tissue - the parts inside a joint that hold everything together.

It can run in families, and in babies, it’s often part of a totally normal spectrum. Their little bodies are still developing muscle strength and control, so typically they all start out a bit bendy. But when joints are particularly mobile or hypermobile, it can affect how babies move and interact with their environment.

How Does Hypermobility Show Up in Baby Development?

Here are some common ways hypermobility might appear in babies:

Delayed milestones: Your baby might take a bit longer to roll, sit, crawl or walk. That’s because their muscles are working overtime to stabilise their extra-flexible joints - I often explain to parents that it's like their baby is trying to negotiate legs and arms that feel a bit like play-doh!
Floppy posture: They might look “floppy” when you pick them up or lie them on their back/tummy. Their core muscles are still catching up - a common trait in hypermobile babies.
W-sitting: A baby with hypermobile hips might often sit in a W-shape (knees forward, feet out to the sides). As much as it might make parents wince, it’s usually comfy for them, but can put a significant amount of strain on their knees and ankles (which can then later affects their walking pattern!).
Leaning or slumping: When learning to sit, they might lean on their hands a lot or slump to one side - its normally a sign their trunk muscles are still building up strength.

Should I Be Worried?

Not necessarily! Lots of babies with hypermobility catch up beautifully. The key is giving them the right support and plenty of chances to build muscle strength in a fun, safe way.

But if you're noticing your baby struggling with tummy time, not meeting milestones, or seeming unusually floppy, it’s always worth having a paediatric physiotherapist take a look. Early support can make a big difference

Typical Gross Motor Milestones (0–18 Months)

2–3 months: Begins to hold head up during tummy time
4–6 months: Rolls from back to tummy and tummy to back
6–8 months: Sits without support
7–10 months: Crawls or moves around on tummy/hands and knees
9–12 months: Pulls to stand and cruises along furniture
12–15 months: Takes first independent steps and starts walking
15–18 months: Walks confidently, squats, and begins to climb

How to help your hypermobile baby

Here’s what you can do to support gross motor development in your hypermobile baby:

Tummy time is magic: It strengthens shoulders, arms, core and neck. All essential for gross motor progression.
Floor time over container time: Less time in bouncers, car seats, highchairs or prams means more opportunities to explore movement without restriction.
Encourage active play: Reaching, rolling, crawling - anything that gets your baby moving will help build strength and coordination.
Watch the W-sit: Gently guide your baby’s legs into other sitting positions, like cross-legged, long sitting or side sitting, to support healthy hip development and reduce the strain through their knees and ankles - especially important for hypermobile joints.

A Quick Note from a Physio

Hypermobility isn’t a “bad thing” - it’s just one variation in how little bodies are built. With the right play-based support and encouragement, your baby can still build fantastic strength, balance and coordination.

If you ever feel unsure or want tailored advice, don’t hesitate to reach out to a specialist who gets baby movement. That’s what we’re here for.

Got a question about your baby’s movement? Feel free to contact us by phone, email or via social media - we're always happy to help!