I used to wear the Wave Rider, and I experienced a very similar pain to what you describe. The version I had could be bent in half with little resistance across the arch. If this is still the case, I would not recommend wearing this shoe anymore as it does not have the midfoot support you need. The fact that your left shoe wears faster in the heel than the right would not a compensation in your stride to absorb impact. I'm surprised Ryan has not posted yet about how too much cushioning and support in the shoe may be part of the problem. I tend to agree with Ryan on that point. I will say the following, but please consider that I am not a doctor and am only relaying what worked for me. After I had a similaar problem with pf and shin splints I did the opposite of Rita and began a regimen of barefoot walking and eventually barefooot running to the point where about 15% of my weekly miles are without shoes. My feet, ankles, shins and calves are in much better shape now than before because all the muscles are being used to support the arch and natural running form. I have not experienced a hint of pain since my feet got accustomed to change. I have had a lot of success with this and believe it has been the most impactful change I have ever made to my running. Look into it, I can only say how well it worked for me.