Physical Development

Baby Not Using One Arm or Hand

Medically reviewed by Dr. Sarah Chen, MD, FAAP · Board-Certified Pediatrician

Content reviewed against published AAP, NIH, CDC guidelines

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Your baby's physical development is unique, and concerns about baby not using one arm or hand, here is what you need to know.

The short answer

If your baby consistently avoids using one arm or hand, it deserves evaluation. Before 18 months, babies should use both hands roughly equally - strong hand preference before this age can indicate a concern with the less-used side. Possible causes include brachial plexus injury (Erb's palsy) from birth, nursemaid's elbow, fracture, or neurological differences. Early identification leads to better outcomes with therapy.

Key takeaways

  • If your baby consistently avoids using one arm or hand, it deserves evaluation. Before 18 months, babies should use both hands roughly equally - strong hand preference before this age can indicate a concern with the less-used side. Possible causes include brachial plexus injury (Erb's palsy) from birth, nursemaid's elbow, fracture, or neurological differences. Early identification leads to better outcomes with therapy.
  • Usually normal when: A slight preference for one hand after 18 months of age
  • Call your doctor if: Your baby has not moved one arm since birth
  • Varies by age — see the age-by-age breakdown below
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What Parents Should Know

According to AAP, NIH, CDC guidelines, if your baby consistently avoids using one arm or hand, it deserves evaluation. Before 18 months, babies should use both hands roughly equally - strong hand preference before this age can indicate a concern with the less-used side. Possible causes include brachial plexus injury (Erb's palsy) from birth, nursemaid's elbow, fracture, or neurological differences. Early identification leads to better outcomes with therapy. At 0-3 months, a baby who does not move one arm from birth may have a brachial plexus injury (damage to the nerves that control the arm), which can happen during a difficult delivery. The affected arm may be limp, held in an unusual position, or have a weaker grip. Most brachial plexus injuries improve significantly with physical therapy within the first 3-6 months. Early evaluation and intervention are important. It is generally considered normal when a slight preference for one hand after 18 months of age. However, you should contact your pediatrician promptly if your baby has not moved one arm since birth.

Sources: [1], [2], [3]

Normal vs. Concerning

Usually Normal
Worth Discussing
A slight preference for one hand after 18 months of age
Your baby has not moved one arm since birth
Temporarily not using an arm that was recently vaccinated (injection site soreness)
Your toddler suddenly stops using an arm they previously used normally
Using both arms but one slightly less skillfully in the early stages of a new motor task
There is visible swelling, deformity, or severe pain in the arm

By Age

What to expect by age

0-3 months

A baby who does not move one arm from birth may have a brachial plexus injury (damage to the nerves that control the arm), which can happen during a difficult delivery. The affected arm may be limp, held in an unusual position, or have a weaker grip. Most brachial plexus injuries improve significantly with physical therapy within the first 3-6 months. Early evaluation and intervention are important.

3-12 months

At this age, babies should be reaching for toys and bringing hands to midline using both arms. If one arm is consistently less active, it could indicate a milder brachial plexus injury, muscle tone difference, or early signs of cerebral palsy (hemiplegia). Your pediatrician will check arm strength, range of motion, reflexes, and whether both hands open and grasp equally. Early physical and occupational therapy can be very beneficial.

1-3 years

Hand preference normally develops between 18 months and 3 years. A strong preference for one hand before 12-18 months, or a complete avoidance of using the other hand, is not typical and should be evaluated. A sudden change where a toddler stops using an arm they previously used normally could indicate nursemaid's elbow, a fracture, or a neurological event.

What to Tell Your Pediatrician

  • Describe when you first noticed baby not using one arm or hand and how it has changed over time.
  • Note your baby's current age and which age-specific patterns you are seeing.
  • Mention if your baby consistently reaches with only one hand and ignores the other.
  • Mention if one hand stays fisted while the other opens and grasps normally.
  • Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
  • Bring a list of any questions or observations you want to discuss at the appointment.

What Should You Do?

When to take action

Probably normal when...
  • A slight preference for one hand after 18 months of age
  • Temporarily not using an arm that was recently vaccinated (injection site soreness)
  • Using both arms but one slightly less skillfully in the early stages of a new motor task
Mention at your next visit when...
  • Your baby consistently reaches with only one hand and ignores the other
  • One hand stays fisted while the other opens and grasps normally
  • You notice a difference in arm strength or movement between sides
  • Your baby was noted to have a difficult delivery and one arm seems weaker
Act now when...
  • Your baby has not moved one arm since birth
  • Your toddler suddenly stops using an arm they previously used normally
  • There is visible swelling, deformity, or severe pain in the arm
  • Loss of arm use is accompanied by other new neurological symptoms like facial drooping or difficulty walking

What You Can Do at Home

  • Keep track of when you notice baby not using one arm or hand — noting the time of day, duration, and any triggers can help your pediatrician.
  • Remember that a slight preference for one hand after 18 months of age — this is generally within the range of normal.
  • At 0-3 months, focus on observation rather than intervention unless your pediatrician advises otherwise.
  • Provide plenty of supervised floor time and tummy time to support your baby's physical development.
  • While monitoring at home, seek immediate care if your baby has not moved one arm since birth.

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 Prefers One Hand Too Early

True hand preference should not develop until at least 18 months to 2 years of age. If your baby consistently uses only one hand and ignores or avoids using the other before 18 months, it may indicate that the less-used hand or arm has reduced strength or coordination. This is different from a slight preference and is worth discussing with your pediatrician.

Nursemaid's Elbow (Pulled Elbow) in Baby or Toddler

Nursemaid's elbow is the most common orthopedic injury in children under 5. It happens when a ligament in the elbow slips out of place, usually after a pulling or swinging motion on the arm. The child suddenly stops using the affected arm, holding it still at their side with the palm turned inward. It is not a dislocation or fracture, and it is easily fixed by a doctor with a quick, gentle maneuver. Recovery is immediate - most children use the arm normally within minutes of reduction.

Baby Not Grasping Objects

Babies develop voluntary grasping gradually over the first several months. Most babies begin reaching for objects around 3 to 4 months and develop a reliable grasp by 5 to 6 months. If your baby is under 4 months and not yet grabbing things, this is completely expected and normal.

Milestone

Milestone Checklists by Age

Track your baby's developmental milestones from birth to 5 years with age-specific checklists.

Milestone

Month-by-Month Development

Detailed monthly development guides from birth through 24 months.

Guide

When to Call the Doctor

General guide on when to call the pediatrician, visit urgent care, or go to the ER.

Frequently asked questions

Is baby not using one arm or hand normal?
If your baby consistently avoids using one arm or hand, it deserves evaluation. Before 18 months, babies should use both hands roughly equally - strong hand preference before this age can indicate a concern with the less-used side. Possible causes include brachial plexus injury (Erb's palsy) from birth, nursemaid's elbow, fracture, or neurological differences. Early identification leads to better outcomes with therapy.
When should I call the doctor about baby not using one arm or hand?
Your baby has not moved one arm since birth Your toddler suddenly stops using an arm they previously used normally There is visible swelling, deformity, or severe pain in the arm
When is baby not using one arm or hand normal?
A slight preference for one hand after 18 months of age Temporarily not using an arm that was recently vaccinated (injection site soreness) Using both arms but one slightly less skillfully in the early stages of a new motor task
What causes baby not using one arm or hand?
If your baby consistently avoids using one arm or hand, it deserves evaluation. Before 18 months, babies should use both hands roughly equally - strong hand preference before this age can indicate a concern with the less-used side. Possible causes include brachial plexus injury (Erb's palsy) from birth, nursemaid's elbow, fracture, or neurological differences. Early identification leads to better outcomes with therapy. Common explanations include: A slight preference for one hand after 18 months of age. Temporarily not using an arm that was recently vaccinated (injection site soreness).
What should I mention to my pediatrician about baby not using one arm or hand?
You should mention baby not using one arm or hand at your next visit if: Your baby consistently reaches with only one hand and ignores the other. One hand stays fisted while the other opens and grasps normally. You notice a difference in arm strength or movement between sides.
Is baby not using one arm or hand normal at 0-3 months?
A baby who does not move one arm from birth may have a brachial plexus injury (damage to the nerves that control the arm), which can happen during a difficult delivery. The affected arm may be limp, held in an unusual position, or have a weaker grip. Most brachial plexus injuries improve significantly with physical therapy within the first 3-6 months. Early evaluation and intervention are important.
Is baby not using one arm or hand normal at 3-12 months?
At this age, babies should be reaching for toys and bringing hands to midline using both arms. If one arm is consistently less active, it could indicate a milder brachial plexus injury, muscle tone difference, or early signs of cerebral palsy (hemiplegia). Your pediatrician will check arm strength, range of motion, reflexes, and whether both hands open and grasp equally. Early physical and occupational therapy can be very beneficial.
Should I go to the ER for baby not using one arm or hand?
Seek emergency care if your baby has not moved one arm since birth, or if your toddler suddenly stops using an arm they previously used normally. When in doubt, call your pediatrician's after-hours line for guidance.
Does baby not using one arm or hand go away on its own?
In many cases, baby not using one arm or hand resolves on its own, especially when a slight preference for one hand after 18 months of age. By 1-3 years, hand preference normally develops between 18 months and 3 years. A strong preference for one hand before 12-18 months, or a complete avoidance of using the other hand, is not typical and should be evaluated. A sudden change where a toddler stops using an arm they previously used normally could indicate nursemaid's elbow, a fracture, or a neurological event.
AAPNIHCDC

References

  1. [1]American Academy of Pediatrics. Brachial Plexus Injuries. HealthyChildren.org. AAP
  2. [2]National Institute of Neurological Disorders and Stroke. Brachial Plexus Injuries. NIH
  3. [3]Centers for Disease Control and Prevention. Developmental Milestones. CDC

Doctor Visit Checklist

Bring this checklist to your next pediatrician visit to discuss Baby Not Using One Arm or Hand.

Things to mention

  • Describe when you first noticed baby not using one arm or hand and how it has changed over time.
  • Note your baby's current age and which age-specific patterns you are seeing.
  • Mention if your baby consistently reaches with only one hand and ignores the other.
  • Mention if one hand stays fisted while the other opens and grasps normally.
  • Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
  • Bring a list of any questions or observations you want to discuss at the appointment.

Observations to share

  • Your baby consistently reaches with only one hand and ignores the other
  • One hand stays fisted while the other opens and grasps normally
  • You notice a difference in arm strength or movement between sides

Urgent signs to report immediately

  • Your baby has not moved one arm since birth
  • Your toddler suddenly stops using an arm they previously used normally
  • There is visible swelling, deformity, or severe pain in the arm

My notes

From ismybabyalright.com — free, evidence-based baby health guides

All content follows our editorial policy and is reviewed against published clinical guidelines.

2,705 evidence-based guides6 authoritative medical sources5 medical advisory board members

Related Resources

Milestone ChecklistsEarly Intervention DirectoryDevelopmental ActivitiesEmergency ContactsBaby Tracker

Bottom line

Most cases of baby not using one arm or hand are normal. Talk to your pediatrician if your baby has not moved one arm since birth.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.

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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 Prefers One Hand Too Early

True hand preference should not develop until at least 18 months to 2 years of age. If your baby consistently uses only one hand and ignores or avoids using the other before 18 months, it may indicate that the less-used hand or arm has reduced strength or coordination. This is different from a slight preference and is worth discussing with your pediatrician.

Nursemaid's Elbow (Pulled Elbow) in Baby or Toddler

Nursemaid's elbow is the most common orthopedic injury in children under 5. It happens when a ligament in the elbow slips out of place, usually after a pulling or swinging motion on the arm. The child suddenly stops using the affected arm, holding it still at their side with the palm turned inward. It is not a dislocation or fracture, and it is easily fixed by a doctor with a quick, gentle maneuver. Recovery is immediate - most children use the arm normally within minutes of reduction.

Baby Not Grasping Objects

Babies develop voluntary grasping gradually over the first several months. Most babies begin reaching for objects around 3 to 4 months and develop a reliable grasp by 5 to 6 months. If your baby is under 4 months and not yet grabbing things, this is completely expected and normal.

Should I Use Adjusted Age for My Preemie's Milestones?

Yes — for premature babies, developmental milestones should be assessed using adjusted (corrected) age, not chronological age, until at least 2 years of age. Adjusted age is calculated by subtracting the number of weeks your baby was born early from their actual age. For example, a 6-month-old born 2 months early would have an adjusted age of 4 months, and should be assessed against 4-month milestones. Most pediatricians use adjusted age for developmental assessment through age 2-3, and for growth charts through age 2.

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Baby-proofing a small apartment is absolutely possible and focuses on the same key safety principles as any home: securing furniture to walls, covering outlets, locking cabinets with hazardous materials, and ensuring safe sleep spaces. Small spaces actually have an advantage - there is less area to monitor. Focus on eliminating the most dangerous hazards first: falls, poisoning, choking, and burns.