Now the way I heard the story (and I have yet to see this verified by an historian but it sounds real good... and believable *grin*) is that the Filipino arts essentially kicked off Western Boxings transition from Queensbury Rules (fists out front, arms 70% extended or so) to the modern stance of elbows against the body, hands protecting the chin.
As the story goes, it was not just the chinese that were brought in as labour to the westward expansion in the US but also South-East asian immigrants. Of course, human nature being what it was, fights broke out between the local population and the workers and when Filipinos duked it out with caucasians the results were devastating. The Filipinos used a tight, elbows in, fists up stance that the locals found hard to penetrate. Furthermore once inside that extended arm range, the Filipinos were able to deliver devastating inside punches. queensbury Rules became obsolete and the locals started adapting to the tighter, more protective stance we see now in Boxing.
Again I cannot verify this, but it does sound good! *smile*
Rob