Reduce Friction to Reduce Shear

December 21, 2014 by · Leave a Comment
Filed under: blister care, Foot Care, Foot Care Products, Sports 

I have often mentioned the website BlisterPrevention.com.au as a great source of information on blister care. Rebecca Rushton, manages the website and is on top of developments in the prevention and care of blisters. She’s a podiatrist in Australia – and a friend.

Through research and looking at the mechanism of how blisters form, Rebecca has changed some old theories of what causes blisters. Heat, moisture, and friction were always considered the three contributors of blisters. Further consideration has found that shear is a major factor. Shear and friction combine to cause blister formation.

You must reduce friction to  blister-causing shear.

You must reduce friction to blister-causing shear.

I want to quote a blog post by Rebecca about Healing Foot Blisters Faster to help you understand more about friction and shear.

“You know friction is responsible for friction blisters. But I bet you think friction is rubbing. It isn’t. Friction is about grip. High friction means two surfaces grip together. Low friction means they don’t … they’re slippery.

“Here’s how friction is responsible for foot blisters … There is high friction in your shoe. There just is. This means your skin grips your sock; and your sock grips your shoe. All three surfaces grip together so your foot doesn’t slide around in your shoe.

But with every step you take, your bones are moving around under the skin. And while the skin is stuck and the bones are moving back and forth. Everything in between is pulled and stretched. This pulling and stretching is what causes blisters.

We call it shear. And it needs high friction to get anywhere near blister-causing.”

With this opening, Rebecca starts to explain the effect of shear and friction on blister formation. She talks about cutting friction levels, especially when a blister develops, and gives examples of six friction reducers. Some of these are better than others.

We have always tried to reduce friction in both preventing blisters and when treating blisters. As Rebecca says, and I support, “Otherwise all that stretching (shear) continues at the blister base while it’s trying to heal. Making it hurt more. And taking longer heal.”

So take a moment and click on the Blister Prevention link and read Rebecca’s full blog post. While you are there, I encourage you to subscribe to her email list.

More on Shear and Blister Treatments

August 26, 2013 by · Leave a Comment
Filed under: blister care, Foot Care, Footwear 

Back on June 17 I introduced the concept of shear with a post by podiatrist Rebecca Rushton from Australia who has studied blisters and identified shear as a major factor in blisters.

It’s best to start by refreshing our memories about what was shared on the previous article. Here’s the link in case you want to see the full post: An Introduction to Shear and Blister Formation. Otherwise, here’s a short piece from that post:

Poor blister prevention outcomes are due in no small part to the misunderstanding of the cause of this obstinate injury. The force that causes ‘friction’ blisters is not friction. And it’s not rubbing. It’s shear. But if you ask 100 people the question “what causes blisters”, nobody would answer “shear”. Shear is the sliding of layers across one another – internal layers that are structurally connected. Those connections can break and when fluid fills that cavity, you have a blister! What Does Shear Look Like?  Try this … Step 1: Place the tip of your right index finger on the back of your left hand. Step 2: Wobble it back and forth but keep it stuck to the same bit of skin. Notice how your skin stretches? This is shear and this is what causes blisters. Shear might look like rubbing but it’s not. Notice how your finger tip has not moved relative to the skin of the back of your hand? But your hand skin has moved relative to the underlying bone. This is shear. Your skin doesn’t need anything to rub over it for blisters to form. It just needs shear (this stretching of the internal tissue layers) to be excessive and repetitive.

That’s shear.

Managing shear is key to managing blisters. Let’s look at several ways to reduce shear.

The first way is to make sure your footwear fits. Many people buy shoes that seem comfortable in the store but don’t make sure they feel ok by wearing them around the house for a few days. Make sure they have enough room in the toe box both in height and length. Make sure there is not undue pressure on soft tissues over any bony spots (sides of the forefoot, ball of the foot, sides and back of the heel, over the instep, etc.). Make sure they are not too loose, allowing too much movement leading to skin abrasions, hot spots, and then blisters.

Using a cushioning product is a second way to reduce shear. This might be a gel pad under the ball of the foot or under the heel bone, or a replacement insole meant to pad and cushion.

Applying power during an adventure race

Applying power during an adventure race

A third method is to manage skin moisture. This can include skin-drying strategies and skin lubrication. Studies have shown that you can reduce the incidence of blisters by keeping the skin either very dry or very wet. Drying the skin can be done with powder, benzoin, alcohol wipes, and antiperspirants. Lubricants can include SportSlick, BodyGlide, BlisterShield, and other popular products. Zinc oxide is also effective at controlling moisture. The method of having runners train with wet feet has been successfully used by Shirley Thompson and Vicky Kypta of the Jungle Marathon Amazon. They have found that the feet of their race participants have been better with this suggestion given to runners before the race.

The fourth method of controlling shear is with socks. This may include double layer socks or wearing two pairs of socks – a thin liner and usually, a thicker second sock. This allows movement between the two sock layers. Injinji toe socks are great for those with toe blister problems.

Next time, we’ll talk about  a fifth way to reduce shear – Engo Blister Prevention Patches.

In the mean time, check out ZombieRunner for many products that can help with cushioning, skin-drying and lubricants, and socks.

A Foot Care Success Story

March 17, 2013 by · 2 Comments
Filed under: blister care, Foot Care, Foot Care Products, Health, Sports 

Every so often I hear a foot care story from an athlete that intrigues me. It’s fun to read their story about their issues with their feet and then the steps they took to find answers.

One of the best examples of this is Nathan’s story on page four in the 5th edition of Fixing Your Feet. He told the story of how he studied foot care techniques and learned hot to manage his feet – and successfully finished Racing the Planet’s Australia race.

Then the other day I received an email from Karen. I liked her story and asked if I could share it with my readers. She agreed. Here is what she wrote.

First, I am extremely prone to blisters. Initially I thought it was friction. I tried Hydropel, but its sticky nature attracted dirt but did nothing to calm my problem. At Fruita one year, Lisa and Jay (Smith) Batchen shared their knowledge in a presentation about the three primary causes and the light bulb went off. Hydration is my primary issue – specifically bloating.  The bloating happens because I’m no longer processing fluids.

After working thru formulas and cause and effect for several years on my own, I finally solicited help from Scott Jurek -I knew him from Coyote events. Mutual friends had helped me focus on running nutrition, but I wasn’t making progress on my own. Scott helped me maintain my ability to process fluids and enabled me to delay bloating and blisters.

When I get blisters, they’ll either start as a hot spot on my pads or a painful toenail. I get them under my toenails (which I keep extremely short) or the entire pad of my foot/feet will get it. Over New Years with a very low mileage base, I went to California and ran/hiked 34 miles. Had a hot spot early that I actually taped, and a blister on a toe but that was it – a sign that I was on the right track!

I’ve also become smarter on dealing with my blisters. I still get them, but they aren’t crippling. Once after my first attempt at the Leanhorse 100, they were so bad they caused me to miss the cutoff, and they got dangerously infected. Two years later, I went back and finished – it was my first 100. I still got blisters but they didn’t prevent me from meeting my goals.

Here’s what I do now for my feet other than monkey with hydration:

  • Work on my calluses and keep my toenails trimmed
  • Get my orthotics re-surfaced at least a couple months before event
  • Keep my shoes and socks current too and only use Smartwool socks
  • Train on the exact terrain I expect and work on the plan for my feet – it’s just as important as my physical and nutritional race plans
  • My starting feet recipe is to use BodyGlide on my feet before putting on socks. Then change my socks every 20 miles if I’m running anything over 50K.
  • Carry a foot kit on my back at all times with a couple Engo Pads for hot spots on my orthotics, a couple of alcohol wipes, blister pads and a safety pin, and duct tape for real emergencies on a pencil or on my water bottle
  • A full fledged foot kit for crew or in a later drop bag with new supplies for my carry kit, Desitin if it’s wet conditions, and tape/scissors/tincture for the next defense. An injection devise and zinc oxide and Second Skin/New Skin as final defense. I had to do all three lines of defense to actually finish Leanhorse, but we did it.

Thank you Karen for sharing your foot care plan.

Blister Volunteers Needed

January 4, 2013 by · 1 Comment
Filed under: blister care 

For years blister care has been fairly standard. Many athletes use Second Skin over the top of a blister and then apply tape to hold that in place. Some still use Vaseline. Others will drain the blister and cover with a Band-Aid or athletic tape. And some will use zinc oxide under tape.

All can work – but some work better than others. I’ve seen many runners who have tried one of the above with poor success.

Sometimes the lack of blister patching success happens because of a poor tape job. Maybe too little adhesive around the patch and it didn’t stick. Maybe the blister was not lanced correctly and refilled with fluid. Or maybe the Second Skin migrated under the tape and folded on itself or might have been old and too dried out to work as designed. Or the Second Skin made the skin too moist and maceration occurred, causing more problems. Or too little Vaseline or zinc oxide was used and friction reoccurred, leading to an increase in fluid.

So here’s the deal. I am interested in hearing from a few athletes, runners or adventure racers, walkers or hikers – who get serious blisters almost every time they go out. I don’t mean a minor ¼ inch blister, but a blister ½ inch or larger, anywhere on the foot. And especially those where the roof tears off, leaving raw skin underneath. The worst, the better and the bigger the better. This is not a prevention item but would be used as a treatment for formed blisters.

I have a product to test and need four to six testers.

Send me an email and tell me about yourself, what you are doing when you get blisters, and how you have treated them in the past – what you have tried and what worked or didn’t work. If will do my best to respond to all who send me an email. Please sned an email rather than a comment on the blog.

I’ll pick the best of the worst cases and supply you with sample product and suggested ways I want you to use it in the trial. I’ll give you forms to use to record your results and may ask for a photo or two. I will ask for your confidence in the trail until I can judge the results.

I make no guarantees as to whether this will work or not. But I think it’s worth a test. This is not a homegrown product but one made by a medical company.

Lubricants – One Bad and Lots of Good

August 4, 2012 by · 1 Comment
Filed under: blister care, Foot Care Products, Health, Sports 

This post came about because of a Backpacker magazine article about skills. One of the items was about endurance and was for, “Blistered feet during a high-mileage trek.”

The tip was to, “… protect against hot spots by applying a skin lubricant like Vaseline to high-friction areas…”

I’m sorry, but I think Vaseline is a bad choice.

When I ran my first ultra, back around 1982, there was not a huge choice in lubricants so Vaseline was commonly used. But I learned very quickly that its stickiness helped it collect dust and grit, sand and dirt, and other things that found their way into your socks and shoes. Once absorbed into my socks, it also became stiff. I looked for an alternative and discovered Bag Balm, which I used for years.

Over the years, Vaseline has been surpassed by lubricants that are slicker without attracting “stuff’ that can cause hot spots and blisters, that last longer, that don’t cake up on your socks, and that are much more effective.

So, here’s my choice for a bad lubricant: Vaseline.

And here are my choices for good lubricants:

Sportslick Skin Lubricant 

  •             Tube
  •             Solid Stick
  •             Pocket Slick

BodyGlide 

  •             The Original Anti-Chafe Balm
  •             FootGlide Foot Formula
  •             Ant-Chafe with SPF 25 Balm
  •             BodyGlide Anti-Chafe for Her
  •             Liquefied Powder
  •             WarmFX Anti-Pain Balm

BlisterShield

  •             Powder
  •             Roll-On
  •             Towelettes

RunGuard

  •             Anti-Chafe Stick
  •             Anti-Chafe Stick, Sensitive Formula

Hydropel Sports Ointment

Bag Balm

Many of these are available through ZombieRunner. Click on “Anti-chafing & Skin Care.” I you are looking for a new lubricant, or want to try one of these, check them out through  ZombieRunner.

Disclosure: Clicking through to ZombieRunner and making a purchase credits me with a few pennies to support this website.

Blood Blisters

July 22, 2012 by · 1 Comment
Filed under: blister care, Foot Care 

In reality, most blisters don’t have blood in them. Repeated heavy pressure (friction) or simply long periods of pressure can turn an ordinary blister into a blood blister.

The fluid will go from clear to light pink, and with continued pressure, to blood red.

The general rule of thumb is not to lance and drain any blood blister. You may have to pad the area to take the pressure off the blood-filled skin. You need to now how to manage a ruptured blood blister.

Here’s why. The problem with blood blisters is that by draining them, the athlete’s circulatory system is opened to possible infection. In a sterile environment or at your home, this may not be an issue. However out on a trail, or somewhere where the athlete may be unable to keep his feet clean, it’s a different story. Where the blister is on the foot can present more problems. A blood blister on the side of the heel is not as problematic as one on the bottom of the foot. The opened blister is exposed to dirt, grime and any bacteria on whatever is touching the skin. Blood blister must be treated as wounds.

Another issue is whether the athlete has he right supplies in his foot care kit to patch the blister. Opening it up and not applying antibiotic ointment and a covering it is a huge mistake.

I tell athletes that normally blood blisters are not lanced because that is the wise thing to say. If everyone thinks they can simply lance them, without fully understanding how to care for them, we’ll have a lot of people with infected feet.

At Badwater last year we had a runner with a very large heel blood blister. She was from Brazil and would be flying home – but she was also a diabetic. Because of her diabetic status, we declined to lance the blister. It would not have been safe.

Arch of the foot blood blister

Arch of the foot blood blister

The photo here is from last week’s Badwater Ultramarathon in Death Valley. The runner had completed the 135-mile race. I talked to him at the finish line and told him the pitfalls of lancing a blood blister. I told him to shower and be careful of popping it and to come see us in the medical room if it did pop. It popped when he was in the shower, the best of all places.

I cleaned the area with alcohol wipes and lanced the blister with a #11 scalpel. I made three cuts so any more fluid would be forced out as he walked. I expelled the blood and applied a generous layer of antibiotic ointment. A gauze 4×4 was placed over the top and then the foot was wrapped with Coban, a wrap material that sticks only to itself. I gave the runner a Zip-Lock bag with a small tube of ointment, several more 4x4s, a Popsicle stick to apply the ointment. I told him he could unwrap the Coban and reuse it multiple times. Then I asked him if his Tetanus was up to date after which I gave him the usual infection speech.

Recheck the blister three times a day for signs of the infection. Each time you check, apply a new coating of antibiotic ointment and change the dressing. Early treatment can keep the infection from becoming more serious.

An infected blister may be both seen and felt. An infection will be indicated by any of the following: redness, swelling, red streaks up the limb, pain, fever, and pus. Treat the blister as a wound. Clean it frequently and apply an antibiotic ointment. Frequent warm water or Epsom salt soaks can also help the healing process. Stay off the foot as much as possible and elevate it above the level of your heart. If the infection does not seem to subside over 24 to 48 hours, see a doctor.

It’s wise to keep a tube of antibiotic ointment in your foot care kit. You may never get a blood blister, but then again, you might. And if you get one, it may not rupture, but then again, it might.

It’s better to be prepared by knowing how to care for blood blisters.

 

Looking at Shoe Uppers

May 3, 2012 by · Leave a Comment
Filed under: Foot Care, Footwear 

Last month I was at my local REI store to conduct a clinic on foot care. At the same time, they held a footwear festival, which had eight footwear companies represented.

I noted something about some of the shoes that is valuable to know if you are shopping for shoes. Specifically, the materials of the shoe’s upper.

I have two photos to share with you. The shoes in these photos are made by Salomon. In fair disclosure, I have several pairs of Salomon shoes that I received as swag for working medical at races. I find they are well made and are easy to fit to my feet.

Shoe with a mesh upper
Shoe with a mesh upper

The first photo shows a shoe that is typical of many shoes today – by most of the companies. The shoe’s upper is made with a mesh material. Whether it is one or two, or even more layers is not important. It’s mesh.

Wearing shoes with a mesh upper will generally help keep your feet cooler. But the mesh allows minute particles of sand and dirt to get inside, onto and into your socks, and on your skin. Those particles can cause friction and over time can cause hot spots and then blisters to develop. Yes you can wear gaiters, but the usual gaiter design covers only part of the front of the shoe’s upper. Stuff still gets inside. The alternative gaiter is a design that covers the full shoes, from the outer sole up over the ankle. A few months ago, I did a review of a gaiter that covers the whole shoe. Here’s the link.

Shoe with a non-mesh upper

Shoe with a non-mesh upper

The second photo shoes a different shoe, also made by Salomon, that has an upper made with a non-mesh material. This upper will keep sand and dirt out of the shoe. A gaiter with this shoe will be useful if you are running in a sandy, dusty, or dirty course, where you would likely get stuff into your shoe through the top of the shoe.

To be truthful, I feel strongly that trail runners should wear gaiters regardless of what shoes they wear. Gaiters are good proven equipment.

If you have a race or event on your summer calendar that involves lots of sand and loose dirt, keep the material of your shoes in mind when planning. Something as simple as a non-mesh upper can save your feet.

Blister Prevention 101

October 2, 2005 by · 2 Comments
Filed under: Footcare, Footwear, Health, Sports, Travel 

Blisters are very predictable. Take three elements, moisture, friction, and heat, common to your feet when you run, and the likelihood of a blister appearing is high. The longer these elements exist on the feet, unattended to, the greater the risk. So, what can we do to reduce one or more of these elements?

Proactive or Reactive
You have the option of being proactive or reactive in managing
blisters. The proactive runner chooses to take steps to prevent
blisters before they develop. The reactive runner treats the blisters
after they develop. Many reactive runners simply think blisters are a
normal part of running. Wrong! Working with the blister prevention
options below can help eliminate one of the most troublesome problems
in walking, running, hiking–any sport that stresses your feet.
     The first order of business is to recognize that you, and you alone, need to find what will work on your feet. Others can give suggestions, but what works for another may not work for you. What follows is a synopsis of options you need to consider….

Read more

Lubricant or Foot Powder?

September 24, 2005 by · Leave a Comment
Filed under: Footcare, Footwear, Health, Sports 

Many athletes have been raised on the common belief that one of the best ways to prevent blisters is to use a lubricant. The use of a lubricant has been proven to reduce friction which causes hot spots, blisters, and after prolonged friction, calluses.
     Vaseline has been used for years but is no longer the best choice. It’s greasy, can cake up on socks, and tends to attract grit particles that can become an irritant and themselves cause blisters. Better choices are newer products like BodyGlide, Bag Balm, Blistershield Roll-on, and SportsSlick. Many of these are petroleum-free, waterproof, non-sticky, and hypoallergenic.
     For athletes in conditions where their feet are exposed to extended periods of moisture, there are several lubricants that are better than any others. Hydropel and Friction Zone are advanced skin protectants. These are water and sweat-resistant.
     Use a lubricant where you need it—between the toes, on the balls of the feet, or on the heels. If you have a history of blisters, you’ll know where it should be applied.
     Some people, however, use a lubricant and still have problems. If this is you, a good idea is to try using a powder. Lubricants will soften the skin and for some, this makes the feet more sensitive to the stresses of walking, running, hiking, etc. In some cases, you might even feel the weave of the socks as an irritant. The softened skin can lead to painful feet, and in some cases, even blisters.
     There are some great powders to try. Zeasorb and Odor-Eater’s Foot Powder are both great super-absorbent and will not cake up. Gold Bond is also a high-quality powder. A unique powder is Blistershield’s Miracle Powder. Its super slick compound reduces friction better than any other powder while repelling moisture.
     There are several tricks to using either a lubricant or powder. They need to be reapplied if your event lasts more then several hours, or if you go through a lot of water or a lot of dirt or sand. Clean off the old coating before applying the new one. Shake the powder into your socks and then shake the socks to distribute the powder. If you are prone to athlete’s foot, use an anti-fungal powder or lubricant.
     Lubricants and powders are valuable tools in the war against blisters. Try one and if problems persist, try the other. They’ll keep your feet happy.