Lots of folks stand up all day for work. They tend to complain about their feet hurting.
We're obviously designed for some kind of sitting. Our bodies bend very comfortably that way. If you walk uphill for ten miles, your body really wants to sit down on the nearest log or rock to take a rest (though how this was supposed to be comfortable back when we used to be naked is a mystery to me). I have no doubt that our ancestors used to sit down to rest. Probably to eat, and to drink water, and to talk, and to weave those loincloths which would be necessary to make sitting down on a log much less uncomfortable.
Our backs and feet suck for standing all day. Mind you, our backs and feet suck for pretty much everything.
I've been using a standing desk for about a month now. I tend to move in place quite a bit, shuffling my feet around, hooking a foot or thigh over a stool, and shifting weight between my legs.
The two things I've noticed are significant tightening in my lower back and discomfort leading to pain in my heels. If I stand barefoot for much of the day, the heel pain can be so bad that there's a sort of burning sensation as I lay in bed at night.
Wearing comfortable, supportive shoes has greatly reduced the heel pain. You could counter that I simply need to spend more time on my feet to condition myself, but as I saw no improvement in the pain over the course of weeks, I'll be disinclined to believe you. :-)
So you cant jump from shoes-all-your-life to no shoes. Nike Frees are a set of shoes which go from a lot of support to no support. Buy the middle nike free and use it for about 1 month and then move to the thinnest nike free for another month.
My dad used to have knee issues like crazy. He now moved to a village and never wears shoes. All his knee issues are gone. Better yet he can run into a river as if it was a paved road. (Riverbeds are covered in small slippery rocks which make it very hard to walk on)
Also you probably have some kind of problem with the fascia at the bottom of your foot. Get a tennis ball and use it to massage your whole foot. Do it once a day.
It will hurt like hell to start but your feet will feel awesome after it. After a few weeks the initial pain will go away completely.
My point in posting my experience is that everyone is different, and people who say, "just do X and it will solve all your problems," have very little likelihood of being accurate. I'm glad your father is doing well, but trust me, I have a host of unavoidable, congenital issues that I have to deal with. Many, many people have other sorts of congenital issues which will make going barefoot painful.
you probably have some kind of problem with the fascia at the bottom of your foot
Nope. The pain is primarily around the edge of the heel. It's hard to explain, but definitely not tendon or ligament pain.
I used to have the kind of heel pain that you describe when standing barefoot, and used Superfeet insoles in every pair of shoes I used. Ever since I started massaging the bottoms of my feet by "standing" (without full weight, obviously) on a 1" bounce ball and rolling it around under the arches and the front of the heel, that has almost totally gone away. The first time I did it, it was incredibly painful, but I noticed improvement almost immediately. Give it a try. I also find that massaging the soleus and gastrocniemus muscles in the calf by using the knee of the other leg helps.
Mind you, our backs and feet suck for pretty much everything.
I tend to think that apparent effect comes from habitual misuse of the body.
It's possible that millions of years of mammalian evolution could have just screwed-up and puked-out some creature that was mal-adapted everywhere but somehow took-over the earth. But I suspect that what's happening is that human are pretty adapted to many activities but we are so darn flexible to we put themselves in situations even beyond our adaptability.
Well combine that with the fact that we weren't really living very long. Our ancestors certainly did not live up to the age of 80 (even within the last century), so the adverse health effects of sitting down can really just be a result of the fact that most people are now surviving long enough to experience them.
We're obviously designed for some kind of sitting. Our bodies bend very comfortably that way. If you walk uphill for ten miles, your body really wants to sit down on the nearest log or rock to take a rest (though how this was supposed to be comfortable back when we used to be naked is a mystery to me). I have no doubt that our ancestors used to sit down to rest. Probably to eat, and to drink water, and to talk, and to weave those loincloths which would be necessary to make sitting down on a log much less uncomfortable.
Our backs and feet suck for standing all day. Mind you, our backs and feet suck for pretty much everything.