Time to change my shoes

I noticed a couple of weeks ago that the heel on my left running shoe is badly worn. I was hoping to get another month on those shoes, so I ignored the heel. However, my left foot started feeling weak during the run today, and I'm guessing that the worn heel may be contributing to that. The worn heel causes my foot to tilt backwards a bit. So, on Saturday I'll be wearing a new pair of LOCO Mojo shoes. I've mentioned the weakness in my left foot before, and it wouldn't surprise me if the tenderness was caused by the worn shoes. Ill fitting shoes or worn shoes are two of the common causes of injuries.