Long time, had a number of personal probs of late and not had the inclination to post.
Guess what, I had a minor dose of PF lately. Came from wearing sandals - my wife was in hospital in Greece and I forgot to look after myself -hey presto - strained my PF. OWW! What helped - no sandals! Orthotics (of course) calf stretching and supportive footwear. No miracles unfortunately. I did learn 1st hand that diferent orthotics can make a huge difference. Guess I already new that but it was ultra apparent as a "patient". I have a pair of orthotics I couldnt wear with my tender heel and normally they are my faves. Fortunately I have another pair which are a different prescription and pain gone!
In personal experience it re-affirmed that PF requires a very good fit of the orthotic for comfort or the heel is easily irritated, the orthotic should be firm to give lots of support and yes generally long hours of standing should be avoided as it just plain hurts.
I dont think there is a line you can draw down this one. It is horses for courses.
Anyone who ever says one thing will work for everyone - orthotics, POSE, whatever is deluded and verging on the fanatical.
The human structure evolved to do many things we dont do now. But one of them was NOT to run 100+ miles per week on tarmac therefore there can never be a "correct" or "incorrect" way of doing this. Any one thing ie orthotics or POSE is just a way of manipulating your mechanics to minimise stress on certain structures. If you hit the ground with 3-4 times bodyweight because simply you are running, the ground will hit you back with 3-4 times body weight. Thats it. Orthotics or POSE dont change this. They cant, force = mass x acceleration. What either will do is change the direction of the force and alter which structures are providing the opposing decceleration.
When you are injured it is usually the structure that has been called upon to provide an excessive deccelaration that is hurting eg plantar fascia because your foot is pronating and flattening or ITB because your leg is rotating internally too rapidly. Orthotics or POSE will simply change the mechanics so that this deceleratory force is either changed or shifted elsewhere. A nice way to think about this is its not jumping off a tall building that kills you, its not flying through the air at high speed, its the rapid decceleration as you hit the ground that does the damage. Therefore we need to change the dececeleration eg a very soft thing to land on or put a chute on our backs, totally different but same effect.
When we prescribe orthoses we try to ascertain if we start shifting forces around we will cause new problems. Where we can spot this we may try to sort it before it happens (remember being told to stretch your calves and you didnt do it ?). Sometimes it isnt possible to spot every possible future problem and so occaisionally we get an undesirable result. Some people come back to get an alteration some throw them in the bin and moan to all and sundry.
Now since I have realised that I cant always spot whether my orthotics will cause a problem I try to concentrate on spotting the individual who is not likely to be patient or understand this is not an exact science and I try to not treat them. Tell them to get some emu oil something.