My Baby Seems Floppy (Hypotonia)
The short answer
A "floppy" baby is one whose muscles feel unusually relaxed and who may slip through your hands when you lift them under the arms. Many cases of mild floppiness improve on their own as your baby grows stronger, but it is important to have your pediatrician evaluate your baby to rule out any underlying conditions.
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By Age
What to expect by age
0-2 months
Newborns naturally have lower muscle tone than older babies, and premature infants may feel especially floppy. A baby born at term should show some flexion in their arms and legs when at rest and offer some resistance when you extend their limbs. Significant head lag when gently pulling from lying to sitting is expected at this age, but your baby should still show some effort. If your baby feels completely limp, does not move their limbs much, or has difficulty feeding, let your pediatrician know right away.
3-5 months
By 3 months, most babies have noticeably improved head control and can briefly hold their head steady when held upright. During tummy time, they should be lifting their head and beginning to push up on their forearms. A baby who still feels very floppy at this age, cannot lift their head during tummy time, or slips through your hands when lifted under the arms should be evaluated. Your pediatrician may order blood tests or refer you to a pediatric neurologist.
6-9 months
Babies are typically sitting with support and working toward sitting independently. A baby with significant hypotonia may struggle with sitting, have difficulty bearing weight on their legs when held in a standing position, and may feel like they fold in half when you try to sit them up. Many babies with mild or benign hypotonia are making progress by this point, especially if they are receiving physical therapy. The distinction between a baby who is progressing slowly and one who is not progressing at all is important.
9-12 months
Most babies are pulling to stand, cruising, and preparing to walk. Babies with hypotonia may reach these milestones later, and that is often okay if they are making steady progress. Physical therapy can be very helpful in building strength and confidence. If your baby shows no interest in weight-bearing, seems to be losing skills rather than gaining them, or has additional concerns like feeding difficulties or developmental regression, your pediatrician will want to investigate further.
What Should You Do?
When to take action
- Your baby feels a little softer or more relaxed than other babies but is still meeting motor milestones within the expected timeframe.
- Your premature baby has lower tone that is gradually improving as they approach their adjusted age milestones.
- Your baby is more flexible or "bendy" than average but is gaining strength and progressing through motor skills.
- There is a family history of being very flexible or having loose joints, and your baby is otherwise developing well.
- Your baby consistently slips through your hands when you lift them under the arms.
- Your baby is significantly delayed in motor milestones like head control, rolling, or sitting, and seems to have difficulty building strength.
- Your baby tires very quickly during tummy time or physical play and does not seem to be getting stronger over time.
- Your baby suddenly becomes much floppier than usual, is less responsive, or has a noticeable change in alertness or feeding ability.
- Your baby has significant floppiness combined with difficulty breathing, feeding problems, a weak cry, or failure to gain weight.
Sources
Related Resources
Trust your instincts. If something feels wrong, reach out to your pediatrician.
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Related Physical Concerns
My Baby Seems to Use One Side More Than the Other
Babies should use both sides of their body fairly equally during the first 18 months of life. While slight preferences can be normal, a consistent pattern of favoring one side - using one arm much more than the other, crawling with one leg dragging, or turning the head predominantly one way - should always be discussed with your pediatrician. Early identification of asymmetry leads to the best outcomes.
My Baby Only Army Crawls
Army crawling (also called commando crawling) is a completely valid and normal way for babies to move. Many babies army crawl for weeks or even months before transitioning to hands-and-knees crawling, and some skip hands-and-knees crawling entirely. What matters is that your baby is independently mobile and exploring their environment.
One Side of My Baby's Body Moves Differently
Babies should generally use both sides of their body equally. If one side consistently moves differently, is weaker, stiffer, or less coordinated, this warrants evaluation. Asymmetric movement can indicate hemiplegia (cerebral palsy affecting one side), brachial plexus injury, or other neurological conditions that benefit from early therapy.
My Baby Crawls Unevenly
While some variation in crawling patterns is normal, consistently favoring one side or dragging one limb while crawling warrants attention. Babies should use both arms and both legs relatively equally when crawling. Persistent asymmetry could indicate muscle tone differences, hip issues, or neurological concerns that benefit from early evaluation.
My Baby Still Has the Fencing Reflex (Persistent ATNR)
The asymmetric tonic neck reflex (ATNR, also called the fencing reflex) causes your baby to extend the arm on the side they are looking toward. It should integrate between 4-6 months. If the ATNR persists strongly beyond 6 months, it can interfere with bringing hands to midline, bilateral hand use, and rolling. Evaluation is recommended.
Signs of Ataxia in Babies and Toddlers
Ataxia refers to wobbly, uncoordinated movements that result from problems with the cerebellum (the brain's coordination center). Signs include an unsteady, wide-based gait, difficulty with precise hand movements, and intention tremor (shaking that worsens when reaching for something). If you notice these signs, evaluation by a pediatric neurologist is important.