In this video, we're going to look at blisters and what you can do about them. So,
we're going to look at: Why do blisters form; what's the mechanism behind that and what are
the main causes? Then also, how can you prevent blisters when you're running? And of course,
then we're going to look at treatments, and I'm going to answer specific questions like,
‘Should I pop a blister? or ‘Can I continue running if I have a blister?’ For those of you who
don't know me, my name is Maryke. I'm one of the physiotherapists from sports-injury-physio.com,
where you can get online physiotherapy assessment as well as treatment for your injuries.
Have a look at the description of this video if you want a link to our website.
How do blisters form? Now basically, it's due to shearing forces. Now, shearing forces,
when you have one force working in this direction, another force working in this one,
and in the middle, it’s trying to pull whatever is in the middle apart. Now, your skin is made up
of between four or five layers, depending on what type of skin it is.
And it's the prickle layer in the outer part of the skin that takes the damage. So,
when you have friction – and I'll talk about what types of friction can cause this in a
minute – that pulls the skin in one direction and the basal cells at the bottom in a different
direction, then you get that you get damage in that prickle layer, and there's fluid that seeps
in, and you get that bubble that you know is a blister. Why would that happen? Why would the
shearing forces be so much that you actually get a blister? There are three categories of
things that can cause it. The first is external, which is external friction, and it's the most
obvious one. But I'll explain a little bit more about that as well. Then we’re going to look at
internal friction, which is a slightly strange one because I've never considered internal friction.
And then we're going to look at other things that can actually affect the health of your skin
and therefore predispose you to blisters. The most common cause of blisters in runners is external
friction. And I mean, it's not rocket science; that's the one that we all suspect most often.
And it's basically friction between your sock and your skin. Now, there are several things
that can cause this friction to be more than what it should be and therefore cause it to blister.
And what the research is showing is that very dry and very wet skin prevent blisters; so that helps.
But moist skin seems to predispose you more to blisters. However, if it's very wet for
a long period of time, then the skin starts to wrinkle and that can then cause damage again.
So, wet is good to an extent, but not for too long, and I'll talk about that with treatments,
or prevention, in a minute. Then, if we think of other things that can cause it is, if you have
pressures … pressure areas. So, things like toenails can be an issue if you don't cut
them properly, or calluses, or shoes that don't fit properly, that press into certain bits. If
we think about foreign objects getting into your shoes, basically sand or sticks. So, thinking of
the Marathon des Sable, for instance: If you don't have gaiters there, you're going to end up with
blisters because they will rub on your skin. What am I leaving out here? Yes, so that's the main
reasons why people get blisters when they run. Now, the second thing that can cause blisters is
internal friction. So, it's normal for your bones to move in your foot as you run and as you walk.
But sometimes, if you're not used to the amount of walking or the intensity of the running
that you're doing, there can be excessive movement in the bones,
and they can actually cause friction from inside out and cause blisters. So things ... Well,
I've already mentioned that if the volume is suddenly too much and you don't have the
strength for it, your running form is going to be poor; that can cause increased internal friction.
Also depending on the terrain, so if we think of inclines and super hilly, and you've got to
push off hard, that's going to increase it as well. What's the other one now?
Oh yes! Towards the end of an exhausting run. So, if you're doing a run that's much harder than what
you're used to or really hard, towards the end of that, because you're losing running form, again,
you can get increased internal friction then – I'll give some tips on how to treat
or prevent that in a minute. So then, the last category for causes of blisters is,
if we think of things that can affect the health of your skin. So, the first one there is nicotine.
There was a large study done on military recruits that showed the guys who smoked or the people who
smoked had a much greater risk at blisters. And that's because nicotine actually affects
your collagen turnover. Now, one of the main building blocks of skin is collagen fibres,
and nicotine slows the production of new fibres as well as the repair of damaged fibres. So you
end up with skin that can't repair it so well and that's just a poorer quality. Then, some people
also theorize that if you dehydrate or the skin becomes very hot, that can cause increased risk
of blisters. At the moment, there's no research to say that it does or it doesn't, so it's something
to keep in mind. And staying hydrated is in any case a good thing during sports.
What's the best way to prevent blisters? Well, if we look at the causes, that tells us a lot
about the prevention strategies. So, the first important one is a sensible training plan. And
this is because, one, your skin, like all other structures in your body, can actually strengthen
over time. So, if you progressively expose it to certain volumes of friction from running,
it becomes stronger. And that's why people can run ultramarathons without getting blisters,
while somebody who's really unfit and has not run for a long time and is not very strong,
if they just try a 5 or 10 K, they may end up with blisters, because their skin is just not
strong enough for the volume of the friction. But also, what goes hand-in-hand with that is, if you
try to increase your volume or your intensity too quickly,
there's a chance that actually your muscles aren't strong enough for it, or your endurance isn't that
great, so you'll get tired more quickly – your running form just won't be so good. So for this,
we think of the internal friction again. You're going to get a lot more movement in your bones,
because they're not going to be that well stabilized by your muscles when they tired. So,
sensible training plan, Number One. Number Two is strength and flexibility training. Now,
this may sound strange, but again, it goes hand in hand with the internal friction as a cause.
So if, for instance, your calves are very tight, it may mean that you put more pressure through
your foot when you run, because you've got to compensate for it. Same thing, if your
glutes are weak and they're not working hard enough, again, you may have to be placing a
lot more strain through your feet when you run. So, it's important to make sure that
the whole body is strong and you're flexible in the parts that you should be flexible in.
Then, if we think of a very obvious one, it's, take care of your feet. Basically, cut your
toenails properly, look after calluses. If you're not sure what to do with them, see a podiatrist,
they're really good with foot care instructions and just taking care of it for you as well.
Think about things like smoking and the effect of hydration. So,
everything you can do to keep your skin in good order. Then, if we think about moisture levels,
there are two things that can be useful. One is, try to keep your feet dry because, yes, we've seen
that dry feet have less friction, as well as very wet feet. But if feet stay wet for too long, then
actually it can cause skin damage again. So, ways to keep them dry is, one, moisture wicking socks;
they can help, so, synthetic materials. Which can actually be quite positive, because also,
when I get to socks, you'll see that the synthetic ones may be performing better than natural ones.
So, moisture wicking socks. Secondly, some people have thought of trying to use … anti-perspirant
that you put under your arms, because it stops you sweating, basically. Now, the research is a little
bit mixed with that, that some studies show that it works, others show that it doesn't really work.
There's one study that looked at if you use foot powder versus anti-perspirant,
which one works the best, and it came out that actually the foot powder worked a bit better.
So, these are things to try. Just keep in mind, if you do use an anti-perspirant,
it can irritate your skin, so it can actually make you more vulnerable to blisters as well.
So, it's something to try, but I wouldn't try it on a long run or in a race if you haven't
experimented with it before. But possibly the first line of action is, get proper socks.
Now actually, sometimes the opposite can be useful, that you want to lubricate certain
parts of your foot. So, if you've got a certain area in your foot that always takes the strain,
you may want to put lubrication over that area to prevent it from that much friction. Now, the
research into that shows that, yeah, it does work, and they've looked at different substances to
put on it, and they found that good old Vaseline works the best. So, you don't even have to spend
a lot of money on it. But what they did show was that when ... although Vaseline works the best,
if you have the lubrication on your skin for more than an hour while you're exercising,
then actually it gets turned around, because then your skin becomes too moist
and you’re actually then more inclined to blisters in that area again. So, it can be a solution for
short term, but not for long term; you might need a different solution for that. Good! Then if we
think of socks, there are lots of different things you can look at when we look at socks.
The type of sock; lots of research has gone into it, but still we don't have a definitive answer.
At the moment, it looks as if synthetic fibres are better than natural fibres. By the way, if
you want the research studies about this, you can look in the description of this video. I've also
put some useful links in there in case you don't know what products I’m talking about; it goes to
Amazon. I've just put things that I could find on Amazon on there, 'cause that's where I shop.
OK, so synthetic fibres rather than natural, and possibly slightly thicker socks seem to be better.
But then, in some studies with military recruits, they found if they wore two pairs of socks on top
of each other, the socks take the friction rather than the skin in the sock. But when you do that,
you want a thin synthetic sock underneath a thicker one, so that it really fits like a
glove on your foot. And I'll put a link down in the description to show you an example of one.
Toe socks: I personally don't like toe socks; it irritates me when things are between my toes.
But if you’re prone to getting blisters between your toes and it doesn't matter how you cut your
toenails, it still happens, then trying out some toe socks could be the answer.
You're going to have to experiment with those and see what works best for you.
That takes care of socks, but then it moves us on to shoes. Now, shoes are very obvious. It's:
too big a shoe, too much movement, more friction. Too small a shoe, too much pressure,
and that causes breakdown in the skin again. So, if you've got your shoes on and they don't
feel 100% right, that it feels as if your foot is moving too much in it or feels too tight,
don't run in them. Get different shoes, because they're not properly fitting, then.
Another interesting one is orthotics. So, some people have to, or like to,
use orthotics in their running shoes, which just support the arch or gives a bit more cushioning.
Now actually, there's research going back all the way to 1968 that already showed that
orthotics made of a certain type of material can help prevent blisters, because it absorbs
a lot of the shearing forces, that it goes into the orthotic rather than actually into the
person's foot. Now, the type of orthotic material that does that is … I'm going to read this off
because it is a mouthful … It's closed-cell neoprene rather than open-cell neoprene. And
the difference is that closed-cell neoprene hasn't got air bubbles in it, where open-cell neoprene
is infused with air bubbles to make it more spongy and more shock absorbent. So actually,
the one without it works better if you want to prevent blisters. Now, I looked on Amazon
and everywhere and I couldn't find any prefab orthotics that was made with this stuff. There
was one company in Canada, but I mean, that's not that useful because you can’t order from that
from other parts of the world. So, I would say that if you're interested in this is a solution,
you possibly need to find yourself a good podiatrist who can help sort this out for you.
Then, the last thing that is quite a useful one to keep foreign objects out of your feet is gaiters.
Now, a gaiter is just something that you put round your ankle. It can be made of canvas, it can be
made of neoprene stuff, anything that kind of holds your trousers or that gap between the
trouser and your foot or your running shoe, that stuff can't go in there. And if you're doing any
runs in terrain where there's a lot of grass or there's a lot of sand, these can be really,
really useful. I nearly forgot one of my favourite prevention strategies, which is,
you can cover the problem areas with tape, because quite often if you get blisters,
it's usually always in the same area. Now, my favourite tape to use for this,
which is not really tape, but it's a plaster, is Compeed. So, Compeed's a hydrocolloid plaster,
which ... it's a bit weird. When you touch it, it feels a bit like skin that is quite thick,
but it's brilliant for absorbing friction and protecting skin. So, I've put a link to
that as well in the description of this video because they’re really, really useful plasters,
and they really stick, and they stay on; even if you get really wet, it still protects the area.
How do we treat blisters? Now, the biggest argument with regards to treatment of blisters is,
do we pop it, or don't we pop it? Well, it's a little bit of,
sometimes you do, sometimes you don't. Let me explain. So, if you can, you want to try and
keep the blister intact, that it doesn't pop. And the reason for this is, while it's intact
and you've got that dome over it, you can't get infections going into it. As soon as you pop it,
there's an opening and now it can become infected. So, it'll heal much better if you can keep it
intact. So, if you're not going to pop it, you want to keep it intact, what you can do to protect
it is, cover it with a hydrocolloid plaster, which … there are different brands. My favourite one is
Compeed. There's also Blist-O-Ban ... What's the other one? I forget the name now. Anyways,
I'll think of it in a minute; I'll put all three types in the description of the video for you.
So, just cover it with a hydrocolloid plaster. I like to clean the skin before you cover it, so,
you disinfect the skin, in case it pops while the plaster’s on there. Now, if the blister is quite
pronounced, that is sticking out quite a lot, it may not be comfortable to have the plaster right
over it, because it may cause too much pressure. If that's the case, you can cut a little donut
the size of the blister in the plaster and then put it, that it's kind of around it,
because you'll see the hydrocolloid plasters are quite thick, so if you do that, it means that the
whole plaster and everything is at the level of that blister, and then you can decide whether you
want to put anything over that as well, but just doing that may already be enough. Now, why would
you want to pop it? Sometimes, the blister is just so big that, doesn't matter what you do with it,
it's really uncomfortable, and you can't get your foot in a shoe and it's just not working.
If you're going to pop it, then there are a few things you need to do. First of all, disinfect the
skin, so, make sure that it's clean skin before you start. Disinfect a needle so that that needle
is sterile, OK? Then, make a tiny hole on the side of it, that the fluid can come out the side,
and just push it out gently; make sure your hands, everything is clean, so there's no infection risk.
Then, once it's drained, I would recommend that you again cover it with a hydrocolloid plaster,
because the pressure of the plaster will also stop it from filling back up again.
If you pop it like that and you push the fluid out, you may find if you don't do that,
if you don't cover it with a plaster, actually, it just fills up again. And second, if it's open,
it's more … it's got a bigger chance of getting infection into it. So, you have to cover it up.
Now, if for instance, you tried to keep it intact, but the blister pops in any case, then also just
disinfect the skin, make sure it's really clean, and then just stick a hydrocolloid plaster on it.
Could you continue running while you've got a blister? It's not really ideal,
because first of all, if you have a blister, it's likely going to be painful to run. So,
it's going to change your running style, which can lead to injuries in other parts of the body.
Second, it's very likely to pop if you're going to continue running.
So then it opens the chances or increases the chances of infection. Now, I fully understand
that sometimes you can't not run. Say, for instance, you're busy in a multi day race or
you feel it's really necessary for you to do the training sessions. If that's the case,
then I would definitely make sure that it's clean, the skin, cover it with a plaster, so that
if it is going to pop, it's in a sterile environment and there's less chance of
it getting infected. But yes, think about whether it's worth the risk of infection
versus ... or injury versus just waiting a few days and perhaps doing cross-training instead.