You've got it right. At the bottom of the project's website[1] is a list of publications of which two explain it well - and they're available as free .pdf's:
I think that's the case. Early in the video, she was saying that she couldn't lift her arms anymore. It's like wearing exo-armor all the time for super strength.
1. http://scholar.google.com/scholar?q=%E2%80%9CPassive+exoskel...
2. http://scholar.google.com/scholar?q=A+Simple+Technique+to+Pa...
[1]: http://www.nemours.org/research/labcenter/orthopedics/perl/w...