Short answer
Lifting a baby under the arms with thumbs spread loads the tendons at the base of the thumb, and pain there is often De Quervain’s tenosynovitis. Hours of feeding, rocking and carrying also load the neck, upper back and lower back. Small changes to how you lift and feed, plus gentle strengthening, usually make a big difference.
Common causes
De Quervain’s tenosynovitis
Pain at the base of the thumb and wrist, worse lifting with the thumb spread.
Feeding positions
Looking down and rounding forward for long feeds.
Carrying on one hip
Repeated one-sided loading of the back and hip.
What usually helps right now
- Lift your baby with palms up, scooping rather than gripping under the arms.
- Bring the baby up to you with pillows during feeds.
- Swap carrying sides and use a well-fitted carrier.
- A thumb splint can help settle De Quervain’s.
What to avoid
- Pushing through constant thumb pain.
- Long feeds hunched forward.
When to book an assessment
- Thumb or wrist pain lasting more than two weeks.
- Back pain stopping you from caring for your baby.
Get urgent medical care if
- Numbness or weakness in the hand.
- Back pain with fever or feeling unwell.
How we treat it
- AssessHistory, movement and clinical tests, with screening for anything that needs a doctor.
- ExplainA clear diagnosis in plain language, and what recovery usually looks like.
- TreatHands-on care where it helps: joint and soft tissue work, dry needling or adjustments.
- RebuildExercises and a training plan so it holds up, with an end point.
Questions
What is mommy thumb?
A common name for De Quervain’s tenosynovitis, a tendon problem at the base of the thumb.
Does it go away on its own?
Often, especially with lifting changes and a splint. Treatment can speed it up.