In the spirit of "question everything" I have been experimenting a bit with and without custom insoles the last week or so.
At least in Sweden it is more or less a given that high end skiers and generally everyone buying high end boots always get custom insole molded after the feet. I have several different insoles with varying stiffness in the support.
On the off season I run a lot and I have been using barefoot shoes for almost ten years. No support whatsoever and very thin.
My feet are strong and neutral, so why do I need a custom insole?
So far my experiences are:
I cannot feel a huge performance difference between no soles and stiff soles. I have no video so I cannot say for sure that I don't have an alignment problem without the insoles, like A-frame or so, but I don't think so.
I feel that the fore-aft balance is more responsive without arched soles. The pressure can be moved between the metatarsels and the heel much quicker when the feet are not "disturbed" by the arch supports.
The foot is wider without the insoles, which makes it a bit more painful against the fifth metatarsel.
With insoles I get some minor pain under the arch because of the small muscles being pressed against the support. This does not happen without them.
It feels like whole foot balance is easier without arch support.
Anyone else having any experiences or thoughts?
I've had a lot of custom insoles made for me over the years and pretty much felt the whole concept to be highly overrated. Many times I felt it was just a way for the shops to earn more money and also a lack of knowledge from the shops side. For me the insole had become almost only a matter of fit and comfort. Alignment issues best attended to and fixed by shimming the base of the boot to desired angle and tilting the shaft as desired. I have a very good and rigid foot with a balanced footprint on a sensor pad so I don't need any special alignment or fixes. However, as mentioned by many here before it's very individual.
This year I had my boot fitter talk me into trying a new custom made insole concept. The moulding was done to a very thin top layer with a very delicate and articulated outcome compared to many done to me before. He then foamed underneath and shaped it for desired alignment and fit. At the arch he taped a strip of window insulation to give some room for the "flexor hallucis longus tendon", I think, that stretches and presses against the arch support if footbed is made too high and rigid causing the foot to hurt and dysfunction. I've skied with it since week 8 and it feels great. It makes for slightly less volume in my boot so it can be a bit tricky to get used to at the beginning of the season. I need to take a liner that gives me more room if that is going to be a problem.
I would recommend people to experiment. I'm now skiing with a Dalbello shell, a Head foam liner, a Atomic tongue, a booster strap and a custom insole.