It's weird because 5 years ago I got assessed just by walking and they told me I needed support for over pronating. Now I've signed up for the London marathon I figured I should get some new trainers, was assessed on a treadmill and they told me I was normal. So bought some Brooks Ghost 5 and its been quite painful, pins and needles, maybe just too tight, front of knees hurt a tad and then on Sunday pulled something at the back of my knee. Haven't run since but walking has been difficult, better at the back of the knee but now clicking feeling lower at the top my calf... I have increased my mileage a lot from 6 miles a week to maybe 18 so could that be the cause? Any diagnosis? Can't see a physio till next week unfortunately.