I am currently dealing with the same problem. I managed to get my average from 77-83% down to 63% on the last run I did, this resulted in running about 4km/hr slower than normal, I intend to slow down even more. It felt strange at the very start, like running on the spot almost, but I soon warmed to it. I believe it naturally inclines you to run with the pose method, I barely placed a heel on the ground. Just one word of caution, two days later and my lower legs are feeling it, so possibly allow yourself a couple of days to recovery after your first go.
I also believe your heading for an overtraining related injury. Don't learn the hard way like myself
and so many others... slow down. I am a firm believer that this slowing down will help you to speed up in the long run.