E18: W-Sitting, Not Crawling or Delayed Sitting: Hypermobility (Double Jointed Babies) - the common cause of Developmental Delay

Is your baby unusually flexible or “double-jointed”?

Maybe their legs flop out like a frog when lying down…
Maybe they struggle with tummy time…
Or perhaps they’re not rolling, sitting or crawling yet and you’re starting to worry.

In this episode of the Best For Baby Podcast, paediatric physiotherapist Lisa explains hypermobility in babies: what it is, why it happens, and how it can affect your baby’s development in the first year of life.

Many parents notice their baby is bendy or slightly delayed, but few realise that hypermobile joints can make movement harder, not easier. Because their ligaments and connective tissues are stretchier, hypermobile babies often have to work much harder to build strength and stability.

The good news?
With the right activities and support, most hypermobile babies develop beautifully.

In this episode, Lisa explains the signs parents should watch for, why some babies avoid movement, and the simple ways you can support your baby’s development at home.

Signs Your Baby Might Be Hypermobile

 • Very flexible or bendy joints
 • Legs that flop outwards when lying down
 • Difficulty holding their head up
 • Disliking tummy time
 • Delays in rolling, sitting or crawling 
 • W-sitting
 • Refusing to put their feet on the ground when being helped to stand

If this sounds familiar, hypermobility could be a factor in your baby’s development.

How to Support a Hypermobile Baby

Lisa shares simple physiotherapy principles parents can start today, including:

 ✔ Encouraging plenty of tummy time
 ✔ Activities that build core and shoulder strength
 ✔ Helping babies practice rolling and twisting movements
 ✔ Supporting crawling development (a powerful strengthening stage)
 ✔ Gentle sensory activities that improve body awareness

These small daily movements act like mini gym sessions for your baby’s muscles, helping them build the stability they need for future milestones like standing and walking.

When Should Parents Seek Help?

While many hypermobile babies simply develop a little later, it’s worth seeking a professional assessment if your baby has:

• Delays in multiple developmental areas
• Very low muscle tone or feels floppy
• Limited movement or interaction
• Significant feeding or speech delays

Early support can make a huge difference to confidence, strength and coordination.

Link to vibrating teething ring: Here

🎧 Next Week’s Episode:
We’ll explore how hypermobility affects toddlers and older children, including walking, posture, and coordination.

Connect with Lisa here!

For help on: 

Baby Flat Head Syndrome (Plagiocephaly and Torticollis), click here!

Positional Talipes (Correctable Club Foot), click here!