Transcript: Hi everyone, how are you? Thanks for joining me on this edition of Office Hours May 2023. We are talking all about Injinji toesocks today.
Okay, so Injinji toesocks. Quite common in hikers and runners. I’m sure many of your patients are using them. Perhaps you’re even using them yourself. We recently started stocking Injinji toesocks in the Blister Prevention online store. So I had to go through and choose our range because Injinji have a huge range and there’s no way we were going to stock the lot of them. So it was a difficult task because the range is so huge. I mean, just looking at this little sub selection of socks. How would you choose one from the other?
They differ in several ways. Injinji provide four heights, mainly three heights: the crew, the mini crew and the no show. And they also have this hidden one here. They come in, obviously, different colors and patterns. And I’d like to suggest that most of us, or at least our patients, choose their height, that is their personal preference, and then choose the color or the pattern sock that they like the look of. But we’re going to dig a little bit deeper and see if we can’t get a bit more purposeful about our choices of Injinji toesock. They are classed according to activity. By Injinji Run Ultrarun, Trail and Sport are the main ones. They come in four different thicknesses and they have different fiber content. Mainly either Coolmax or Wool?
So, first things first, which blisters are toesocks good for? They are literally only good for interdigital blisters. And/or pinch blisters. They’re really no different to any other sock for any other blister location. So it’s just blisters between the toes, and pinch blisters. That’s an important point to make because a lot of our patients, when they continue to get blisters under their toenails, or on top of their toes, or under their big toe, they just don’t get that. There’s only a specific subset of blisters that Injinji toesocks are good for.
How do they work?
Let’s get into the nitty gritty. So they work potentially in four ways. Normally, in the interdigital space, it’s a skin-skin interface. But with toesocks, we create additional frictional interfaces. So we’ve just got, we have more pairs of materials and every pair of materials has a specific coefficient of friction. And potentially, one of these new interfaces has a lower coefficient of friction than the skin-skin interface. So we’re turning the skin-skin interface into a skin-sock, sock-sock, and sock-skin interfaces.
It also manages moisture. Normally, it’s skin on skin, There’s nothing there to manage the moisture. But with two layers of sock between there, that sock will be doing something with the moisture. So, there’s a moisture management component. And then there’s two mechanisms that are related to their cushioning. And that is the reduction of pressure, and absorbing shear. So let’s have a look at them on this chart of blister prevention mechanisms. So, the additional interfaces, that’s here. They are aimed at reducing the coefficient of friction. The moisture management that is also here. It’s all about trying to get a very dry skin because we know dry skin has a lower friction level than high skin then wet moist skin. Whether it does or not, who knows.
But at least it is probably a bit drier than not having anything in that skin-skin interface. And then the cushioning component. Cushioning reduces pressure and absorbs shear, yeah. Some of the material undergoes shear within itself, particularly the thicker socks, such that there’s less that needs to happen within the skin.
Pros and Cons
It’s always a good idea to think about the pros and cons of every strategy that you recommend. So that you know that you’re making the right recommendations. The biggest plus to Injinji toesocks is they provide some level of protection for every interdigital space. There’s nothing else that does that, not as a single change. So you change from a normal sock to an Injinji toesock, all of a sudden, we’ve got all those levels of protection.
But the downsides are related to the upsides. Basically, it means that we’ve got a lot more sock layers in the finite area of the toe box. So when we wearing toesocks, we’re actually adding eight sock layers to the toe box area. If this person gets swelling, or they’re doing an activity where swelling is a component, like long distance running or multi-day hiking. And then if they also have to have other preventions or treatments in place, let’s say the toesock didn’t go far enough to preventing blisters and you need at least a dressing, we’re adding even more bulk.
So, if we have a look at a toesock, just looking at those extra eight layers and what that actually looks like in real life, that’s what it looks like. It’s quite a lot more bulk there. Even if you squish it right down, it’s still substantial. If you don’t have a toesock, just get a sock out of your sock drawer. Fold it over once, fold it over twice, and you’ll get an appreciation of those eight layers of sock.
Every time I think about toesocks and the room they take up in the toe box, I think back to this female runner from the Adelaide Ultramarathon in 2014. She had each toe taped with Rock tape, and wore Injinji toesocks. It was a six day ultra marathon and the shoe was just not wide enough to cope with all that. And so she had to cut open her shoe, which is not unusual in ultramarathon – they go to extreme lengths.
Choosing Injinji Toesocks
So let’s have a look at the way that we can choose and that our patients are choosing toesocks.
Height: First of all, they’ll probably choose the height that they prefer. I don’t think this pertains too much to blister prevention. As long as it’s keeping muck out of the, out of the sock, from getting between the sock and the skin, I think it’s much of a muchness – it’s down to personal preference.
Activities: Then there’s activities. Injinji break their socks down into run, ultra run, trail and sport, and a couple of other categories. But these in the main ones, they cater mostly to runners. There’s very few sport, very few trail socks and there’s a few ultra run, but mainly they are in the run category.
Fibers: And there’s two fibers that they class their socks as: either wool, merino wool, or Coolmax. The few socks that are made of wool, they’re about 66% to 75% Merino wool. The other components of the sock, in every sock, are Nylon and Lycra. The Lycra varies between two and five percent. And then the nylon will make up the difference between the Lycra and the main component, which in this case is Merino wool.
By far, Coolmax is the predominant sock fiber used by Injinji toesocks. And if we look at the activity classifications, I kind of expected there to be kind of a sweet spot in regard to Coolmax, and that pretty much every sock would have that sort of narrow range of Coolmax distribution in the sock. But there are actually really quite large differences.
If we think about Coolmax being the most common fiber in Injinji socks, and Run socks being the most common classification, the run socks actually have the least amount of Coolmax, which is interesting.
Now, I don’t know why that is. I have sought clarification – any information as to how and why that is. But nothing’s been forthcoming. And if you also think about the run socks, there’s actually more nylon in them than Coolmax. So, if we’ve got 30% Coolmax and let’s say a 5% Lycra, that’s 65% nylon. So it’s actually more nylon than Coolmax. And yet, if you compare that to the sports socks, it’s deemed there to be more need for moisture-wicking. I guess that’s what I can take from that.
Thickness: And the final classification is thickness. Now, this is what I thought I was going to be swayed by mostly in regard to choosing some Injinji socks for our store. These are the classifications that Injinji use. They’re a bit wordy. So I’ve kind of, just for my own purposes, used these classifications: Ultra-thin, Thin, Padded and Padded+. The plus pertaining just to the toes. There are terry loops in the toes, in addition to the padded construction throughout.
If you think back to the important sock research that we have in regard to blister incidences, this was by Herring and Richie, back in the early 1990s. They found that the thickness of the sock was more important than the fiber composition. I won’t go into the details, but basically, thick was better than thin. That’s all we’ve got as an evidence base. That’s all we’ve got to go on in terms of what’s the best sock.
So, these are the socks that I’ve chosen to stock in our store. They’re all the ones at the top there. The properties are down here. I’ll just orientate you a little bit. The ultra run -they’re all the ones with the padded toes, which is great. Because you know, running a lot means that you need more protection, I guess, and therefore they’re thicker. And we know thicker helps.
However, it also means that there’s a bit of a mismatch in regard to the swelling component that is inevitably a part of ultra running, so there’s probably going to be a time at the beginning of the race when toesocks are a good idea, or at least these ultra run socks. And then maybe get back into a thinner toesock later on, or just into a standard sock. The two wool socks are here. There are more wool socks with Ijinji, but we’ve just decided to stock these two. These are the Sports socks. There’s a couple of Trail, not many trail. And the run are kind of interspersed.
So thickness I think is the main thing to look at here.
I really don’t know what to make of this – the fiber content. Injinji have been around for a long time. They must know what they’re doing. They would have had many iterations, testing, and customer feedback, to arrive at their, you know, the way the socks are composed. So you can only assume that the socks are successful in terms of comfort, and, I don’t know about blister prevention, I’m not sure that’s their main focus. But we’ve got what we’ve got, anyway.
Choosing Injinji Toesocks
In terms of fibers, the way I would deal with this would be, I would obviously choose the height of the sock – that’s an easy way to narrow down the socks that you’re going to choose. Then decide on whether you want thick or thin, or somewhere in between. Make that decision. And whatever the fiber ended up being. Perhaps you can make a choice, perhaps you can’t, depending on what your requirements are for the other two categories. And if you’re getting on well, or let’s say you’re not getting on well with a particular toe sock, let’s say it’s got a low Coolmax concentration, maybe go for a sport sock, and see whether that’s any better – the more Coolmax, we are assuming the better, the moisture management.
On the other side of the coin, if you’re happy with a toesock, it’s performing really well for you, it’s comfortable, you haven’t been getting blisters and you want the same one, have a look at what is the composition of that soCck. How thick is it? What’s the oolmax or wool concentration? And figure it out from there how close you can get to the same sock?
General sock advice
My general advice in choosing socks is, well, for Injinji toesocks, I’ve got to make sure my customer or my patient understands that they’re only going to be better above a normal sock for interdigital and pinch blisters. I would advise thick is better than thin. But I’m completely aware of the fact that we might not be able to get a thick toesock into a shoe, depending on the activity, depending on the individual. But even then, a very thin or ultra-thin sock, there’s got to be some advantage to having those two layers of material between the toes. As long as it fits in the shoe, I would be happy to have a thin sock, more than anything – just get something that’s comfortable.
In terms of moisture management, Doug Richie and I were on Talysha’s P3 podcast a little while ago and we were having a discussion about “What’s the perfect sock”, which is a very difficult question to answer. I’ll refer you back to you the P3 podcast, but Doug queries whether moisture wicking actually occurs in real life. Most moisture-wicking research is in the laboratory, not in an in-shoe environment. And he suspects that wool actually performs better at moisture management. Who knows? It’s a, it’s a complicated little topic.
What to do if blisters continue
But more than anything, if blisters continue, move on to something more specific to that blister’s anatomical location. This is so important. It’s the best way to be thinking about blisters. So if I had a patient who was still getting blisters between their toes or pinch blisters, I would try and understand why.
Why is it happening? Is the toe really adductovarus, and the fourth toe is literally sitting on it and treading on it with every step? If that’s the case, perhaps I’ll try and tape it and derotate that adductovarus toe. Or perhaps I just need to hone in on one particular blister – I don’t need protection between all the toes. Let’s say the fifth toe is a really bad adductovarus toe and I just want to absorb as much shear as possible. You cannot go past a gel toe sleeve for that. There’s some other things that you can read up on here. Of course, always think about how the toes are moving, what’s making the bones move in the toes, because there are certain biomechanical interventions that we can use for total blisters.
Okay, I’m just going to share with you this chart. I’ll continue to share that for about a week and then I’ll probably take that offline.
Okay, let’s get into the Q&A.
QUESTION 1: Joanne asked about Injinji liners with waterproof socks? Well, yes Injinji liners, go for it. If you’ve got the room in the shoe, the only reason you would wear waterproof socks is if there’s going to be a severe waterlogging situation, for example, the Bibbulmun Track in WA. When people start at the southern Albany end, just around Denmark, there’s areas where you are literally knee deep in water for hours at a time. I always recommend waterproof socks. Not for blisters, I’m talking about maceration. Maceration is to be avoided at all costs. When you have to back it up the next day, and back it up the next day. Because you just can’t when you have severe maceration. So if you’ve got to wear waterproof socks, go for it. But don’t wear them if your feet are only going to get a little bit wet. I’d rather opt for some other blister prevention than waterproof socks. I’m always thinking about maceration.
With waterproof socks, water can’t get in. At the same time, water can’t get out. So if your feet sweat a lot, and you do get kind of hot in waterproof socks, if it’s a warm day, especially, there’ll be a lot of sweat. It won’t escape. They say that it’s permeable – the sock is permeable to gases. But if it’s waterlogged on the outside of the sock, that moisture gradient is not favorable for water vapor to move from the inside-out, so you’re going to get a lot of perspiration stuck inside the sock. An Injinji toesock is a great idea for dealing with that moisture a bit. Even if it’s just for the short term – hopefully it is just for the short term. Waterproof socks in themselves are very thick. So we’ve got to think about the fact that we are adding even more bulk by wearing a toe sock, even the ultra thin liner.
Yeah, that basically sums up my ideas on the waterproof socks and the liners. Definitely a good idea to deal with some moisture. You will need a pair of shoes to change into, because your shoes will be waterlogged. Therefore, if you just put a dry pair of socks on and put them in wet shoes, they’re going to be wet. Basic stuff, but people don’t think about these things.
QUESTIONS 2, 3 and 4: Sarah, Simone and Celia ask variations on a theme. Defense Force boot conditions and recommendations, how to prevent blisters in netballers, and trail marathons. My thoughts are this. These are the wrong questions to ask. The more appropriate questions to ask, for preventing blisters, is to think about what is the best prevention for this blister location. From that, you’ll have a list of things.
And you can choose and nuance those strategies according to, the boots in the defence forces, netballers and trail marathons. At the end of the day, the best prevention for a blister is the best prevention for a blister, no matter what you’re doing. You may need to make a compromise for a particular situation. But you’ve got to at least start with the knowledge of what’s the best thing for that blister location. Rather than starting at what is their activity? So there’s no real answer to these questions, I’m afraid. I hope that helps. If you need a hand with this Blister Prevention University is what this is all about.
QUESTION 5: Jamie asked “multi-day running events, blisters drained or not drained”. Well, I like to drain blisters, because if they’re running for days at a time, their blister is probably going to burst itself in an unclean environment, opening it up to infection. So I’d rather do that in a controlled environment. Putting to the side a person’s general health, which of course we must consider, you also need to tell your participant that they need to look after that blister for the coming days. Just because you’ve lanced it now, and dressed it, doesn’t mean it doesn’t need anything else. They’re got a monitor it, they’ve got to put betadine on again, another Band-Aid and they’re monitoring for infection. So they need the gear. They need to be able to do it themselves. And it’s going to take several days to do, to really do it properly.
Another couple of things to think about. Even when you lance a blister with a scalpel, and you’ve got a hole in that blister roof about, about 3-4mm long, you’ll be surprised at how quickly that seals over. So, just because you’ve lanced it once, doesn’t mean you won’t need to lance it later. But the best thing is to implement prevention. The prevention is the thing that negates the blister-causing shear. That means that the blister won’t refill, and it won’t get worse with time, and it will feel better straight away. So yes, it’s important to, this question of draining or not draining, but in every treatment situation, always go for some sort of prevention as well because that’s how they get pain relief. That’s how the blister can start healing, even though they’ve got to still be on it, and how the blister doesn’t get worse.
QUESTION 6: Some great questions from Marion to finish off. “Do you find hydrocolloid plasters worsen deroofed blisters in running or hiking? When would you not use them?” Yes, they definitely can. And you know how they can – where we haven’t implemented prevention. When we do nothing about the blister-causing shear, the blister, I don’t care what it’s got on it, it’s going to continue. It’s going to get worse. The whole point of a hydrocolloid plaster is that you leave it on for days at a time. Well if you’re hiking, and if let’s say it’s a blister at the back of the heel, and you do nothing to negate the blister causing shear, the whole reason behind it, then after an hour you’ll need to change that hydrocolloid. And that’s just a complete waste of a hydrocolloid. You might as well be using a Band-Aid and changing that regularly. Because they’re a lot easier to deal with.
But if you put a hydrocolloid on and you implement some really great prevention, then you can be sure that you’re not making that blister get worse with time, then a hydrocolloid is fine to use. But the thing is, a lot of people In most situations, they don’t have great prevention to implement. I do, when I go to the races, I have the best prevention and I’m not afraid to use a hydrocolloid. If I’m confident enough that we’ve reduced the blister-causing shear. So that’s the difference. The other thing that can make them worse – oh no, that’s if it’s, a lot of people use hydrocolloids on intact blisters and blisters with a torn roof. And when you peel that off, it just makes everything worse because you often peel the whole roof of the blister off.
QUESTION 7: Marian had another great question. “Case studies on orthotics reducing blisters at the interphalangeal joint of the hallux.” Yes, they do. I would say the best way to deal with a sub hallux blister is to deal with the mechanics. So we are thinking of functional hallux limitus or structural hallux limitus. If it’s structural, there’s probably not much that you can do mechanics-wise, bone movement, wise – so, we’re thinking bone movement, this part of blister prevention. But the aim, if it is a functional hallux limitus is we don’t want that first metatarsal to dorsiflex. We want the hallux to be able to dorsiflex on the metatarsal, which means the metatarsal has to plantarflex. That is what facilitating the windlass mechanism is all about. So any orthotic modification or even a non-orthotic thing like a heel lift, for example, anything that you can do to facilitate the windlass mechanism will get that first met head weight bearing, and take a bit of the pressure off the sub hallux.
So that’s it. Alright guys. I might wrap it up there. If you want to know more about blisters head over to the pro site, that’s pro.blister-prevention.com. First things first, sign up for the free CPD. And go from there, you can have a look at Blister Prevention University in here, and some other things. And if you have questions, let me know
I hope this has been helpful in regards to choosing Injinji toesocks. I hope that you just understand the socks a little bit better. Not just understand more, but also understand what we don’t know about how they work. But they definitely have a place in blister prevention. So much so, that’s why we’re stocking them in our store. Any questions, let me know and until next time, which is the first Wednesday of the month, I will see you in June. Many thanks. Bye now.
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