Nearly 20 year ago, I went to a doctor to get approved for health insurance. He put me through a stress test, running on the treadmill, which I did barefoot, as I’d not brought running shoes with me (I didn’t know what a stress test was back then). I’d been running and even winning races at the time, so I was surprised when I developed plantar fasciitis from the barefoot treadmill test (it was a very long one, as I was fit). It was very painful, and I went to see the leading running podiatrist in NYC. He told me that my arches were collapsing and I needed custom orthotics ($500!). In the mean time, I was not to run and I was to put heel lifts in my shoes. None of this made any sense to me. I reasoned that I would not have torn my plantar fascia if the muscles in my feet were doing their job, which I reasoned they were prevented from doing in my cushioned running shoes with heel lift and rocker sole. Rocker sole! Whose idea was that? Prevent the toes from grounding and doing their work — toe flexors, which support the arches, are prevented from working or at best delayed from engaging in most running shoes!
Plantar fascia is a band of tissue that gives the arches support in simple standing. Once one begins walking and running, toe flexors should come into action to better support the arches. Cushioned shoes with heels and rocker soles make it difficult for toe flexors to act, resulting in unnatural strain on plantar fascia. Arch supports can somewhat mitigate the strain, of course, but serve to prevent normal action of foot muscles and generally weaken the feet. If one lands on the heel of the foot in running, toe flexors will not engage to prevent excessive pronation, so then a runner becomes dependent on motion-control shoes, again, weakening the feet.
Note that toe flexors insert into the bones of the lower leg. In pronation and supination, the tibia and fibula rotate allowing the toe flexors to absorb shock and helping them to deliver force to the ground in leg extension.
I put on racing flats with no cushioning, heel lift or rocker sole, and began doing a series of uphill sprints, putting my toes flexors into action. I avoided downhill running for a brief period, as shock absorption uses pronation, putting added stress on my already torn plantar fascia.
Well, I got better, and 20 years later I’m still running, often barefoot, with no foot pain and no collapsed arches. My arches are nicely mobile, I think.