I just got back to running after a fairly long break of about 3 months off. This is my fourth week back running and I have been dealing with pain in the back and inside of my heel in my left foot only when pushing off my big toe in the gait cycle. This started within my past 3 runs. It initially started when I changed my form into focusing on landing more on my Midfoot whereas before I used to heel strike a lot and over-stride. That run where it started I had jumped up to my first 40 minute run after only doing 20 minute runs for a couple weeks. I took a day off and ran again and it was much worse and I had trouble walking the rest of the day.
The day after it felt a lot better I could walk normally again but I decided to take 3 days off to be safe. Came back today and it still was bugging me to the point I could not push off my big toe in my left foot. I iced it after and it was very uncomfortable to walk around and push off the big toe because I was feeling pain in the back and inside of my heel. It also is very sore first thing in the morning but I don't think its a plantar problem because its not under my heel but at the back and the inside.
Also, for what's it worth my left foot has a low arch while my right foot has a very high arch. This causes my left leg to be weaker to the point where I can feel that my right leg is stronger and my left leg looks smaller. I currently have been running in Brooks Ghost 12 and Nike Pegasus Turbo 2s fwiw. Has anybody had something like this before? Could it be some kind of ligament or muscle strain?