I've never had plantar fascitis! But I do know how to treat it. No blisters and I credit my darn tough socks. Hubby is wearing the Merrell Phaserbound mid waterproof boots and they are perfect for him. No blisters and no pain. Take into account that he's a 53 year old over weight male. If I'd listened to him and taken my mid weight hikers I probably wouldn't have this problem. There is a lot of road walking and a lot of gravel and rocky roads. The easiest terrain was the Hospitales because it was natural mountain terrain.
I would definitely consider a light weight hiking boot instead of hiking shoes if you suffer from any history of Achilles' tendon problems (I had my left on injured a few years back and it's acting up) or even mild heal pain or plantar fasciitis. Good orthotics for your personal issues and Darn Tough socks. Wide width shoes and for sure size up. I got that part right.
The problem on the Primitivo is the hard surfaces you are walking through. It's tough on feet. Unlike what I'm used to in Alaska which is all wilderness and no real trails. Hard ball surfaces cause plantar fasciitis. I'm very glad I had waterproof shoes though. With my short nylon gators my feet stayed completely dry in downpours and deep mud. No waterproof shoes would have had me in soaking wet feet for hours. Probably caused a blister.
I don't recommend my Merrill MOABs for this trail. Too light weight. I should have worn my Vasque St Elias (wide size even though I have normal width feet. They swell like I broke something when hiking in heat). The Merrill's are very comfy but definitely a long day hike with no load kind of shoe.
Another thing to consider. Despite saying that I was packing my Teva Olowahu flips, at the last minute I packed the Teva terra lite sandals. Normally a good camp shoe but anything with a heel strap is a bad idea when you have Achilles problems. The mildest cinching causes pain. Alternative? I'd bring a super light weigh cushiony shoe like this cheaply made sketchers. Give up weight elsewhere. Feet are the most important thing.
I'm skipping 2 stages. We took the bus to Lugo (along with 5 other pilgrims with same foot issues) this morning and I am resting in the hotel (Mendez Nuñez) with my feet elevated, iced, and prescription strength dosages of ketoprophen. Which is sold over the counter here so I was able to easily obtain a few boxes. It's a Cox2 NSAID but seems to work better for me than Naproxen (Aleve). We are waiting for friend Steve (Stfina) to arrive tomorrow. We start walking again on Wednesday.
I'm also lightening my pack by about a 1 1/2 pounds. Sending Ivan my puffy jacket (only needed it over the Hospitales route and that night before in Campiello); my phone backup charger (finding the new iPhone 7 Plus doesn't run out of battery life especially without a data connection); my long sleeve hiking shirt; my silk long johns that were never used; and ditching the blister packs of allergy meds we ended up not needing. Also ditching 1 pair of my exofficio bra since I only need one pair to walk. And one pair of socks. I only intended to bring 3 pr and I extra made its way in there. Don't need more than 3. Will probably throw away one of our pieces of Dr Bronners since we only have 4 days left and this'd suckers last forever.
Still carrying 3 liters of water at least until we reach Melide since there are still not enough waster sources between here and there. Temps later this week will be hitting mid 80's so I'll need all that water. After that I'll decrease it to 1.5.
I think that should help my feet. I may also ditch my rain skirt. I walked in pouring rain with just my purple rain skirt and t-shirt in high 50's and was extremely comfortable. Obviously not ditching the large quantities of pain killers
luckily I also brought a few muscle relaxants that have helped tremendously at night. Thanks to my 80 year old doctor who gave me Valium (original use was as a muscle relaxant) because she KNEW I'd have spasm in my legs during this kind of hike (other patients had told her stories so she made sure I was prepared). I have just enough for each night left.
I hope this is helpful information. Some things to think about any way.
Oh! Every albergue in the Primitivo has thick good blankets for those of you who get cold. No shortages.
I may even ditch my sleeping bag at this point. Pensiones all have linen. I probably won't, though.