This could be the next big breakthrough in improving the results of bystander CPR.
Regardless of any specific technique, the objective of CPR is to compress the center of the the chest 2" at a rate of 100 per minute; with 2 ventilations performed every 30 compressions when possible.
This takes a tremendous amount of energy, and can become extremely fatiguing in a very short time. Most people can only maintain this tempo for a minute or two before slowing or reducing the compression depth. Any CPR is still better than nothing.
The muscles in your legs are almost always going to be stronger and more resilient than your arms, and will fatigue much slower than your upper body.
Bob Trenkamp of Saving Lives in Chatham County (SLICC) has been studying and lobbying for this technique for several years. The American Heart Association (AHA) actually reviewed this technique in 2012.
Any technique that makes bystander CPR more effective...or more likely...is worth serious consideration in my book.