CNCed footbeds?

[Zirbl]

Here's a way of doing footbeds I'd not encountered before, though it's evidently been around a while - computerised cut-out on the basis of a 3D scan, although he clearly does some extra work on it. What do the experts on here make of it? Not much info in the video - amid some nonsense from the voiceover he just says that he uses carbon for cyclists and a rubber material for ski racers because it makes for good grip on ice.


Any views on this method and material? How does it accommodate different feet other than by matching their shape?

 

[Zirbl]

@Philpug I posted the video I'd seen this method in because it's probably easier to see something than go off my description, but on reflection I don't really want to put bootfitters in the position of directly commenting on a colleague's work. If you'd like to delete it, I'll repost a more general query without the video. My questions are about the method, not the individual.

 

[Swiss Toni]

I’m by no means an expert, but I am familiar with the system.

It looks like he’s using something similar to the Paromed system, a computerized system for making orthotic insoles https://paromed.de/en Your feet are scanned on a flatbed scanner; the scans are then imported into the software, where the insoles are modeled and any corrective elements are incorporated; after modeling, the insoles are milled from a foam blank on a CNC router. I don’t think they are intended for use in ski boots, but that doesn’t stop some boot fitters from selling them.

There are a number of orthopedic shoemakers in the German speaking alpine countries who also do ski boot fitting; they are usually pretty good at modifying ski boots, but they often make insoles that are not ideal for skiing. As they have officially recognized qualifications, it’s often possible to get your health insurance to cover at least part of the cost.

Hubert Rabensteiner, the guy in the video, is a shoemaker by trade; after finishing his apprenticeship, he worked for Strolz. He is best known for making the LEKI branded carbon fiber arm and leg protectors that some WC racers use.

 

[Zirbl]

Your feet are scanned on a flatbed scanner; the scans are then imported into the software, where the insoles are modeled

That's what's new to me. Had the scanner treatment before, but that just got info that was followed up by non-weight-bearing fitting. Think they could have done that without the machine. But an orthopaedic insole isn't just a mold of the sole of your foot is it - does the operator add inputs to the machine, or add materials after the modelling, or is the software equipped to give you what you need and not just a reverse imprint?

There are a number of orthopedic shoemakers in the German speaking alpine countries who also do ski boot fitting; they are usually pretty good at modifying ski boots, but they often make insoles that are not ideal for skiing. As they have officially recognized qualifications, it’s often possible to get your health insurance to cover at least part of the cost.

Yeah, some are very keen on cork. Tried some in the other day that I gave up on years ago, just to feel the difference to what I have now. Pretty useless.

I don’t think they are intended for use in ski boots, but that doesn’t stop some boot fitters from selling them.

He says specifically they're better for grip on ice, so these ones must be intended for high-level use. Think I read somewhere that the ones in the video were EVA, not rubber as he calls it loosely here. One of the things that intrigued me was that it was the first time I'd heard a bootfitter talking about how the material used assisted with the interaction with the snow, rather talking about influencing the position of the foot. I'm sure that comes into it, but it's the first time I've heard it sold like that.

Hubert Rabensteiner, the guy in the video, is a shoemaker by trade; after finishing his apprenticeship, he worked for Strolz. He is best known for making the LEKI branded carbon fiber arm and leg protectors that some WC racers use.

I was more interested in the method than the individual bootfitter, but his endorsements seem to be as good as you can get.

 

[Swiss Toni]

That's what's new to me. Had the scanner treatment before, but that just got info that was followed up by non-weight-bearing fitting. Think they could have done that without the machine. But an orthopaedic insole isn't just a mold of the sole of your foot is it - does the operator add inputs to the machine, or add materials after the modelling, or is the software equipped to give you what you need and not just a reverse imprint?

The operator incorporates any corrections required during the modeling process, and the router mills the insoles from foam blanks. Paramed is not the only computerized system; this is a video of another system, but it’s similar to the Paramed system and should give you a reasonably good overview of how it all works:

He says specifically they're better for grip on ice, so these ones must be intended for high-level use. Think I read somewhere that the ones in the video were EVA, not rubber as he calls it loosely here. One of the things that intrigued me was that it was the first time I'd heard a bootfitter talking about how the material used assisted with the interaction with the snow, rather talking about influencing the position of the foot. I'm sure that comes into it, but it's the first time I've heard it sold like that.

According to his website, he makes his ski boot insoles from EVA foam. They seem to be called milled sports orthoses / insoles in English https://www.bauerfeind-group.com/en...nsoles/details/product/milled-sports-orthoses I don’t think any of the boot fitters who post here have any experience with them. I’m not absolutely sure, but corrective insoles might be classified as medical devices. If this is the case, you may need a prescription to get a pair, and the person making them will likely have to have recognized qualifications.

I can’t really see how an EVA insole that’s been milled to match the plantar surface of your foot would give you better grip on ice or assist with the interaction with the snow any better than a heat molded insole that was specifically designed for skiing. But as I said, I’m not an expert. A major part of his business seems to be fitting Strolz boots, so he will see a lot of skiers who have problem feet. Most of these skiers don’t ski at a very high level and just want to ski pain-free.

These guys say all sorts of things and have lots of pet theories. An Austrian orthopedic shoemaker / boot fitter thought it was a good idea to abduct the foot in a ski boot, Fisher licensed the idea, and we got Soma Tech boots.

I was more interested in the method than the individual bootfitter, but his endorsements seem to be as good as you can get.

Anyone can set themselves up as a boot fitter, so I think it’s important to do a bit of research on their experience before going to see them. It looks to me like this guy has very good tool skills, but his knowledge of skiing biomechanics might not be so good.

 

[Zirbl]

Thanks for all the above.

A major part of his business seems to be fitting Strolz boots, so he will see a lot of skiers who have problem feet. Most of these skiers don’t ski at a very high level and just want to ski pain-free.

Yep, but another part is fitting feet that have made podiums. Dunno who he has now, but he had Strobl and Knauss at one point. Again, the post wasn't supposed to be about him, but having linked to his stuff, it seems fair to point out that he does more than fill a Strolz bucket with foam. He got into supplying WCers via footbeds. Maria Rosa Quario interviewed him not too long ago about it: https://www.sciaremag.it/attrezzatu...iner-ll-meccanico-di-shiffrin-gut-kriechmayr/

I can’t really see how an EVA insole that’s been milled to match the plantar surface of your foot would give you better grip on ice or assist with the interaction with the snow any better than a heat molded insole that was specifically designed for skiing.

It would be interesting to know what density of EVA they are.
If the operator manipulates the system, do we know they're not designed for skiing?
.

 

[Swiss Toni]

Fritz Strobl and Hans Knauss were downhillers. Knaus retired in 2005, and Strobl retired in 2007. They may well have won races using his insoles, but it was a long time ago. This type of insole is designed for walking and other activities that have a gait cycle.

If I have understood things correctly, skiing is a mid-stance activity, there isn’t a compete gait cycle, there is only the mid-stance phase and part of the propulsive phase. So, an insole that is specifically designed for skiing should perform better.

The video shows a pair of Paromed grey/green duel density blanks being milled, these have a hardness of Shore A 50/70, a Vibram boot sole is about Shore A 70. The hardness of the plastic used in heat-molded insoles is Shore D 55.

 

[Zirbl]

Knaus retired in 2005, and Strobl retired in 2007.

Has foot function changed since then?

The video shows a pair of Paromed grey/green duel density blanks being milled, these have a hardness of Shore A 50/70, a Vibram boot sole is about Shore A 70. The hardness of the plastic used in heat-molded insoles is Shore D 55.

I thought they looked softer than all the skiing footbeds I've had made. I can see the logic if you subscribe to the Miller/Schlopy premise of how the foot should pronate. If you want the control of a firm heel cup or what have you, then obviously it's a different story.

I generally take WC endorsements with a pinch of salt. Some of them turn out to be based on someone popping in for a bit of minor work, and if they're long-term, we know no more than that the fitter happened to be a good match for the given athlete. If we accept that the footbed for Hirscher that happened to be underway the very day the cameras were there was for use in a ski boot - on the one hand we know Hirscher doesn't have any problems getting grip, but on the other hand we don't know whether he won races on it or threw it away after one run. Well, I don't anyway.