Is this "stimming"

I just started to notice an odd behavior in my 9 month old.  When I put her in the highchair she instantly pushes her chest and body out against the straps while pulling her legs in and out in a repetitive motion.  She doesn't seem frustrated or uncomfortable.  She does stop after a few minutes.  I don't really notice it in the stroller.  She is a very happy, playful, and loving baby who is meeting all of her milestones.  I have seen this exact behavior before with a friends child who does have developmental delays.  Of course now I am concerned.  Any info would be helpful!

[Jason C Bourret, Ph.D., BCBA-D]

The type of behavior that you describe isn't uncommon in typically developing infants. If you have concerns, continue to monitor her language development and interest in socializing and interacting with others. If you start seeing delays in communication or social development, consider having her assessed by early intervention and autism specialists.

[supermum_ms]

I think your being a little overly concerned, by its self there is nothing abnormal about a child exploring the restraints of a highchair. You said it clearly she is a very happy, playful, and loving baby who is meeting all of her milestones, by that description she would be very unlikely to be developmentally delayed.

A stim is a repetetive action and or behavior that is pleasurable, often to the point that the child will only engage in the behavior that they find most pleasurable. eg rocking motion, flapping hand in front of their eyes etc. Just a basic explanation of a stim.