You asked a question, and I answered it. How is that not help?
Or is it that you didn't get the answer you wanted?
You provided no frame of references, so I had no way of knowing if you were talking about the manufacturer, or a playground or daycare who allowed your child on the device, or who you meant by "them". But it doesn't matter to the question you asked, since there isn't a law that automatically makes anyone liable right out of the gate for medical bills, or for your lost wages. And that is what you asked.
Now, depending on who you were referring to and the circumstances of the accident, there may be some liability somewhere. Or there may not. But the answer to the question you asked is, No.