In reply to Derry:
Do change your running style.
After years of heel striking and injury setbacks that kept me limited to about 30 miles per week, I jumped on the bare foot bandwagon about 12 years ago.
Starting with about 1/4 mile, slowly built it up over 6 months or so.
Now I run with a mid foot strike, and have not had an injury that has stopped me running for years.
I run mostly on fells in innov8 mud claws with no insoles. A bit of road now and then in worn out mud claws.
Have a look at the pose method (technical) or chi running (easier to implement). Worth getting 'ready to run' by Kerry Starret and the trigger point therapy workbook to help prevent niggles becoming injuries.
A change in style was the only way forward for me, but it must be done really very slowly.