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  • Post last modified:December 27, 2020

baby's arm is shakingPin

Dad’s Question:
Our 4 1/2-month-old baby’s arm is shaking! It starts to shake when he is attempting to grab something and can’t get his grip on or when getting annoyed or sleepy and about to cry. It appears it’s mainly when these things are happening around him that this begins.

When we hold his hands, the shaking stops but when you let go, it picks right back up again. The best way to describe it would be as if someone was super excited or nervous that their arms would be shaking in that way.

We don’t know if this is just a part of growing up or something a bit more serious. These happen throughout the day and other times he holds his hands nice and straight.

Is it any kind of neuro problem?? I would appreciate any input!

Thank you!


Easy Baby Life:

Baby’s Arm is Shaking – What’s Normal And Not

Normal Shaking in Baby

What you describe is probably normal shaking due to your baby’s immature nervous system. I remember believing that my firstborn suffered from some kind of brain damage when she was newborn due to her weird movements and shaking… But it turned out to be completely normal newborn movements.

Now, since you are worried, and your baby, though still very young, is not a newborn anymore, let’s take a look at different reasons why a baby might be shaking.

3 Medical Reasons for Twitching and Shaking

Here are a few examples of medical reasons for shaking in babies. There are others as well, so the best you can do is to talk to a doctor!

1. Benign Myoclonus or “Fejerman syndrome”

A brief and involuntary twitching of a muscle or a group of muscles is called myoclonus. Myoclonus can occur episodically through life as hiccups or hypnic jerk (spasms that occur while falling asleep). However, myoclonus can also happen due to a number of neurological disorders.

In children, it is important to distinguish myoclonus from other movement disorders or seizures that might need a specific treatment.

When myoclonus occurs in otherwise normal babies, the health condition is called benign myoclonus of early infancy or Fejerman syndrome. The onset of this health condition is between 3 and 15 months. Affected children usually have normal psychomotor development prior to and after the onset of the first episode and do not show other neurological symptoms.

Abnormal movements often occur while awake or during light sleep and might be triggered by frustration, anger, fear, and excitement.

Benign myoclonus of early infancy does not require treatment and has a favorable long-term outcome. Of course, your doctor has to make the appropriate studies in order to rule out other neurological disorders.

In the video, you can see a baby that was diagnosed with benign myoclonus of infancy.

2. Infant Shuddering Attacks

There is also something called shuddering attacks – may be a bit more similar to what your baby does?

Shuddering attacks can begin as early as 4 months. The shudder is like rapid tremors. It is supposed, though, to only last for some seconds at the time. These shuddering attacks are completely benign and the kids grow out of them. You can read about a well documented case of infant shuddering attack at Neurology.org.

And here is a video showing what such an attack may look like:


3. Seizures

It is important to distinguish seizures from movement disorders. Some of the warnings signs of seizures to look for are the following:

  • The abnormal movements are associated with eye movements.
  • The shaking is not associated with any stimulus. Generally, physiological myoclonus is stimulus-sensitive and may be initiated or stopped by noise or sudden movements.
  • The shaking occurs at any time. If it is is only when changing diapers, feeding, getting angry, etc, it is not likely to be for example a seizure.
  • The shaking continues even if you hold the arm.
  • Shaking that is bilateral is more likely to be a sign of problems
  • The baby is falling behind on developmental milestones

From what you describe, your baby doesn’t seem to have seizure problems. Still, if it was me I would take him to a pediatrician anyway, just to be on the safe side and also to get rid of the worrying.

I hope this helps,

(Answer approved by our Medical Doctors Reference Team)

More Babies With Shaking And Seizure Issues

If your baby’s arm is shaking too, please share your experiences below!

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This Post Has 3 Comments

  1. Dave

    My 3 months old baby shake her legs when she touch objects. We took her to the Dr; she did a blood test and ultrasound. It was all normal but I’m still worried. She is been doing it since from 2 weeks old.

    Her Dr think it’s just a immature nervous system and she will get better.

  2. Sunny

    My Baby is 28 days old and shaking happened today 8-10 times today in the left part of his body. Doctor said it could be due to lack of calcium in the body .

    I am concerned what could be the reason.

    1. Paula @easybabylife

      Hi Sunny,
      Will the Dr check calcium levels? I can’t say what the reason is. Newborn babies tend to do a lot of shaking and strange movements, but it is always best to check it up. Let me know what you found out!