Comment by rossant

That's indeed what I said, but I was cautious. I'd have to dig into the latest literature to be sure, but I don't remember seeing even 1 case where shaking with no impact was independently witnessed or videotaped, and was shown to cause retinal/subdural haemorrhage, with or without any other form of trauma.

In any case, these situations are extremely rare, much more than those involving any kind of head impact.