I have had the pleasure of meeting Dr Astrid Linder on a couple of occasions in the semi-distant past. Thoroughly impressive woman and this field of work (occupant diversity in crash testing) is very much her core area of expertise.

Its been a while, but I believe the point here is that the American model is, as others have said, 30 years old.

There are lots of problems with these 30 year old American models. Crash testing is one. Xray dosage another. Nuclear exposure another. The list goes on. So much of the world still refers back to these ancient models and people, mostly Europeans like Astrid Linder are working hard to modernise these.

Astrid Linder's body of work that culminates in this present dummy takes into account real world data relating to size selection, anthropometry, modern knowledge of response corridors, more advanced assessment criteria, more suitable assessment thresholds, takes into account modern seat design.

If you want to read more detail, you can start by looking up her work on the ADSEAT project (2009–2013) which incorporated work on EvaRID. For example, recording of presentation from 7 years ago: https://www.youtube.com/watch?v=AE51KAnukcg