I would totally buy evidence suggesting they worked different muscle groups though, and even possibly helped correct posture a bit, and that would likely have some significant knock-on benefits if one currently had aches and pains exacerbated due to poor posture.
Yeah, honestly I think the biggest benefit has been to my back. I'm really conscious of my posture because of my back problems, but these somehow improve my posture even more when I'm walking. Don't know if that would benefit the average person, though.