Heel Blister: To Pop or Not To Pop?

 

Hi Dr. Segler,

I've had this blister on my heel for the past three days and it has gotten slightly larger.  I'm wondering if I should allow more time for it to heal or pop, drain, etc?  What's the fastest way to get it healed?

Sincerely,
Ryan M. 
San Francisco, CA

Answer:

Hello Ryan,

A blister on the inside of the heel can be painful when running or even walking.  If you are currently training for a marathon, the last thing you want to do is stop running just because you have a blister on your heel.  But obviously the blister has to stop getting bigger before it is going to heal.

There are only a couple of reasons that a blister continues to get bigger.

1. Friction. If you are continuing to rub the inside of the heel in the same way that cause the blister to form in the first place, the blister will continue to get bigger.

2. Compression. If you repeatedly press on the blister,  the fluid with in the blessed blister will try to disperse outward. Since the fluid is all contained inside the blister, this will continue to separate the layers of the skin from the pressure applied to the blister when the fluid tries to move. This causes the blister to continue to enlarge.

The redness at the border of blister tells me that the fluid is being compressed and further separating the layers of the skin (indicated by red arrows). This of course hurts and makes the heel blister bigger.

If you pop or drain the blister, it will increase the risk of infection. If you pop (or drain) the blister it will feel slightly better in the short term, but it might take slightly longer to completely heal.  As long as all of the irritation to the blister is removed, your body will resorb the blister fluid and heal the blister.

The blister in these images appears to be flat enough that it could be offloaded with some simple pads that could be obtained from a local pharmacy.  The idea is to place felt pads around the blister. By removing the pressure that is being applied to the blister when you walk, it will stop enlarging and it will start to calm down.

If a pad is applied to the heel, it will place all of the pressure around the blister, instead of on the blister. This will significantly decrease both the compression and friction of the blister.  If the oval pads that you find at the pharmacy are not large enough, you can simply cut two of them in half and then apply two separate half-oval pads to completely surround and protect the blister.

Here is an image of the proper pad placement with the red area indicating a blister:

Once the blister has completely healed your next task will be to identify the cause of the blister.  Obviously will not want this to happen again. If you have just gotten a new pair of shoes you want to make sure to break and then more gradually the next time. If your shoes were to loose, obviously want to tie them slightly tighter so that your heel isn't sliding around inside the running shoe. And if the blister happened after running a race (where you were dumping water on your head to stay cool) or from running in the rain, you want to make sure that you avoid getting your feet as wet the next time.

Heal that heel fast so that you can get back to running!

Dr. Christopher Segler, DPM is a runner, 11-time Ironman triathlon finisher and is Board Certified,  American Board of Podiatric Medicine.  His practice is limited to runners, triathletes and other active young adults. He travels frequently lecturing to other physicians at podiatry conferences about the treatment of complicated running injuries.  He performs remote consultations for runners all over the world via telephone and Skype. He also sees patients in person in both San Francisco, CA and Houston, TX.  If you have a question about a running injury that doesn't seem to be getting better, you can reach him directly at 415-308-0833. 

3 Reasons to x-ray a stress fracture from running.

Dear MyRunningDoc, 

I have been ramping up my mileage as part of my marathon training. My foot has been sore and aching when I run. Someone told me that stress fractures don't normally show up on an x-ray until they start healing. If this is true, is there really any point to getting an x-ray if I think I did get a stress fracture from running too much?  

Adam J.

Houston, TX

Answer:

Great question!  This is a question I often hear from runners in San Francisco and Houston. Most runners are busy and don't wont to waste their time going to a podiatry office getting an x-ray of their foot unless they really think the x-ray will change what they need to do to get the foot to stop aching and  heal. (And of course, get back to running and training). But when you suspect a stress fracture, there are good reasons to get an xray.

3 reasons to get an x-ray of your foot if you think that you have a stress fracture.

The 1st reason to get an xray of your foot is to make sure that the metatarsal has not actually cracked all the way through the bone or broken into pieces. 

The 2nd reason is to confirm that the metatarsal, if it is broken, is still in a good position that will heal correctly. If the bone is moved out of place after it has broken that it will not heal correctly and will result in what doctors call a “malunion.” When the metatarsal bone heals in an abnormal position it will alter the way that forces are distributed across the ball of the foot. An unnatural distribution of forces across the ball of the foot will put other metatarsals at risk of problems later. It can also increase the chances of nerve compression that can lead to a neuroma. 

The 3rd reason to get an xray of your foot when you suspect you have a stress fracture is for peace of mind. Having an x-ray confirms that the bone is not actually broken and will not likely get worse if you are walking on the foot as it heals. A fracture walking boot is made to protect a stress fracture and allow you to walk while the bone heals.  if you have had an xray of the foot and confirmed that the bone is not completely broken, and you suspect that it is just a stress fracture, then you can treat it as such and feel confident you’re not going to make things significantly worse if you walk on the foot while protected in a fracture walking boot.

Dr. Christopher Segler, D.P.M. is board certified, American Board of Podiatric Medicine. Because he is an active marathon runner and 10-time Ironman triathlon finisher, his practice focuses exclusively on helping runners get back to running as quickly as possible. He travels back and forth between San Francisco, Houston, and Hawaii so he can often to help Texas and California patients with running injuries.  He also provides web consultations via Skype for injured runners who who are too busy to drive to a podiatry office. If you are in San Francisco and have a question about a running injury, you can reach him directly at 415-308-0833. If you live in Houston and think you have a stress fracture, your can call him at 713-489-7674. Visit our Houston Doc On The Run Practice. Learn more about stress fractures here.

Is this black toenail fungus or a bruised toenail from running?

I have been training for a trail run and have been running on lots of hills in Marin. I recently noticed that I was getting some dark black discoloration of my toenail. I am worried that this might be black toenail fungus infecting the toenail. How can I tell whether the toe is bruised or if I really have a toenail fungus infection? Also, what if anything should I do to treat the black toenail if it is infected?

Thanks,
David, Mill Valley, CA


Black toenails are likely one of the most common injuries I see in runners in Houston and San Francisco. There can be a couple of causes of black toenails from running.

Differences between a bruised toenail and a fungal toenail:
A bruised toenail hurts because 1) there is bruise 2) there is blood under the toenail increasing pressure between the toenail and underlying nail bed. This causes pain in the toenail when you press on it or bump the toenail on the inside of your shoes. Fungal toenails are not usually tender unless the toenail infection has been present long enough to make the fungal nail really thick.  The increased thickness can cause some tenderness, but it doesn't happen quickly.

A bruise comes on quickly, but a toenail fungus infection appears gradually. Bruising will appear within a day or two of your long run, race or whatever injury to the toenail. If you kick a coffee table once with your toe, the toenail may develop a bruise and turn black. If you bump the toe inside your running shoe repeatedly while running down hill (or because the running shoes are too tight) you can also get a bruised black toenail from the cumulative trauma. This can happen overnight.  You wake up and the toenail is black.

The changes in the toenail caused by toenail fungus happen very slowly. The color of the toenail will not change quickly.  The increased thickness, yellow discoloration, white crumbly appearance and dark color of a fungal toenail infection happens so slowly that it is almost hard to notice.

You can learn more about black toenails and toenail fungus treatment here by reading about an example of a black toenail in Houston that actually is just a toenail bruise. You can also read about from runners, blisters and black toenails here.  Learn how a bruised toenail can lead to a toenail fungus infection.

Dr. Christopher Segler, Doctor of Podiatric Medicine is Board Certified, American Board of Podiatric Medicine. He is a 10-time Ironman finisher and marathon runner. He lectures frequently to other podiatrist and foot specialists at medical conferences on the treatment of complicated running injuries and running biomechanics. He is licensed to practice podiatry in Texas, California, and Hawaii. He travels back and forth between Houston and San Francisco to see injured runners who have running injuries that need the fastest treatment based on a runner's goals and running doc perspective. If you live in San Francisco or Marin and have a running injury question call 415-308-0833 to speak to him. If you are in Houston and have a question about a running injury, call him directly at 713-489-7674. 

Popping, Clicking Ankle Pain. What, Why and How!

Hi My Running Doc!

My daughter has sprained her ankles a number of times. She keeps turning her ankles and they swell up. She also seems to have this popping and clicking sound from the ankle when she walks and it's really bothering her.

     Questions:

          Why does that happen?

          How do we fix it?

          What's the surgery that she needs 
          to cure the snapping and pain?

Thanks!

S.B., Berkeley, CA

Answer: Ankle sprains are the most common musculoskeletal injury. In fact, there is no sports injury that shows up in the emergency department more often in a twisted ankle. Fortunately ankle sprains heal just fine most of the time. But in some cases there can be a significant injury to the ankle that prevents them from healing properly and causes problems down the road.

There are 3 primary potential causes of popping and clicking in the ankle that might be associated with persistent ankle sprains and chronic ankle instability.

1. Torn Peroneal Retinaculum

2. Lateral Process Fracture of the Talus Bone

3. Osteochondral Lesion of the Talar Dome

One common cause of popping and clicking in the ankle is from dislocating or subluxing peroneal tendons. The peroneal tendons run down the back to leg behind the fibula. They turn around the end of the fibula as they curve down toward the outside of the foot. 

There is a thin band of tissue called the peroneal retinaculum that holds the peroneal tendons in place behind the fibula. In some cases involving ankle sprains, the peroneal tendons actually fire so hard to try to keep the foot under the leg when you roll the ankle that the perineal retinaculum actually gets torn off of the fibula bone. Because it is torn, the peroneal tendons are not held firmly in place behind the fibula.

When this occurs, the peroneal tendons are free to slide forward over the leading edge of the fibula bone. As the tendons snap back and forth across the fibula, they cause a popping and clicking sound and/or sensation as you walk. When this occurs it is not always painful but it certainly can be painful. It is more worrisome if it is painful simply because this might signify a tear or a split in one of the peroneal tendons.

If one of the peroneal tendons is torn or split it might need a platelet rich plasma injection (also known as a PRP injection) to help stimulate healing. If the torn peroneal tendon cannot heal on its own, it might require surgery to sew it back together. In any event pain in this area should not be ignored.

Another cause of popping and clicking in the ankle can be a misdiagnosed or undiagnosed lateral process fracture of the talus bone. The talus bone is the bone that connects the top of the foot to the bottom of the ankle. Lateral process fractures are sometimes referred to as snowboarders fractures.

We used to think that lateral process fractures were a rare occurrence. However Dr. Segler led a team of investigators through the largest study ever completed on lateral process fractures of the talus. He and his team won an award from the American College of Foot and Ankle Surgeons for this research. What his team found was that these fractures are about 10 times more common than previously thought. They just get missed all the time.Is

Lateral process fractures are frequently misdiagnosed as ankle sprains. Yet a broken bone does not generally heal the same way as a torn ligament. If not treated correctly, the broken bone can develop into a nonunion where the bone actually never heals. When this occurs, there can be continued pain and swelling in the ankle. Sometimes there can be a popping and clicking sensation as well.

The third potential cause of popping and clicking in the ankle after an ankle sprain is an osteochondral lesion of the talus. An osteochondral fracture is a crack in the bone underneath the cartilage. Basically what happens is the ankle rolls and the talus bone can tilt so far that the corner of the talar dome smacks into the tibia bone or fibular bone. If the talus has a hard enough impact as it twists, it can crack the bone and damage the cartilage. 

Sometimes the cartilage and the fractured piece of bone (known as an osteochondral fragment) can become loose. If not treated correctly this may not heal. If the cartilage is loose and has a flap of tissue that flips back and forth it can cause a clicking or popping sensation. This is often associated with swelling and pain in the ankle.

If there is popping and clicking from the ankle, but no history of a serious ankle sprain, the shape of the fibula can potentially lead to subluxing peroneal tendons. The retinaculum might actually still be intact but because there is not a very deep groove in the back of the fibula the peroneal tendon still slide back and forth causing a popping and clicking sensation at the side of the ankle. This can cause peroneal tendinitis.

If this is the case, it is possible to perform surgery to deepen the groove at the back of the fibula in order to help the peroneal tendons stay in place. This will stop the popping and clicking and prevent chronic irritation of the tendon that can lead to tears in the peroneal tendons.

Another related issue with chronic ankle instability and persistently weak ankles is that the ankles can get sprained over and over. If you often find yourself rolling your ankles when walking on uneven surfaces or running on trails, the first step would be physical therapy or a home rehabilitation self-treatment program to try to strengthen the ankles and restore stability.

In some cases of chronic ankle instability the ankles are so weak that the ligaments on the outside of the ankle need to be surgically repaired or rebuilt. 

In any case, if you have popping and clicking, especially associated with pain and swelling of the ankle, it shouldn't be ignored. Get it checked out right away.

Dr. Christopher Segler, D.P.M. is board certified, American Board of Podiatric Medicine. His practice is limited to  runners, triathletes and active young adults who want to stay active. He travels often to accommodate patients with complicated injuries in San Francisco, Houston, and Hawaii. He also provides remote consultations via Skype for injured expat patients living abroad who need expert advice, but cannot readily access a true foot and ankle expert while overseas. If you have a question about a complicated foot or ankle injury that just isn't getting better, you can reach him directly at 415-308-0833. 

Marathon Blister. Should I pop it?

Question:
Hi MyRunningDoc!


I have been reading your site. This blister formed on my heel yesterday. It is huge and painful. I am running in the Avenue of the Giants Marathon on May 5, 2013 and really can't take a break from marathon training. Should I pop it?

Thanks!
W.H., San Francisco CA

Answer:
Thank you for your inquiry! That is certainly a Giant of a marathon blister. I can see how that would hurt and put a damper on your final marathon training.

There is always an advantage and a disadvantage to draining in any blister on the foot that pops up during training.

With a blister that large and a marathon that close, it is unlikely that you would be able to run the marathon without significant pain. In fact the blister is so big it would probably pop during the marathon anyway.

With most small blisters, it is typically better to let them go away on their own. If you do not drain a small blister and can keep it from getting rubbed when you are running, the fluid will gradually recede and the blister will re-adhere. It will eventually peel away revealing healthy skin underneath. It is also the least likely to get infected because you don't open the blister allowing bacteria to get inside the skin.  This actually will heal the fastest and is the safest approach.

Things get tricky when a running blister on the foot gets big.

When you have a big running blister that causes a great deal of discomfort when you run, it actually hurts because the fluid is getting pushed and compressed.  If you step on a water balloon, the balloon will squish outward under your foot. The balloon will push out and stretch as far as it can unless it pops.

So when you run on a blister like this one pictured here, the blister fluid actually pushes and continues to separate the layers of skin at the edge of the blister. This of course causes more irritation and more fluid accumulation, making the blister even bigger as you continue to run.  The only way to stop this process is to stop irritating the blister on the foot. One way to do this of course is to stop running.

If you can pad the blister and keep the pressure off of it you might be able to continue training without the blister getting any bigger.  That would be hard to do given the location of this blister on the inside of the foot and heel. It will be almost impossible to remove all the pressure from the heel inside the running shoe.

If you pop the blister, it will hurt more for the first day or two.  You can decrease the amount of discomfort by using moleskin or another type of blister cover that will stop the friction from rubbing the overlying skin. It may also be helpful to put some padding around the blister in order to decrease irritation.

If you decide to pop your blister, it is always best to drain the blister by making a small hole at the bottom edge of the blister down toward the bottom of the foot so that the fluid will continue to drain downward and out of the blister as it re-accumulates. Typically some more blister fluid will accumulate inside the blister for several days after you pop it.

The skin on the top of the blister is not what is painful. It is the skin underneath. Some people start to drain the blister and realize this and then trim off the entire top of the blister. If you are to do that in this case, it would leave an open sore about the size of a half dollar. This would of course leave an enormous raw spot that would be very painful whenever you run during training. You foot would be killing you during the marathon.

In these types of cases it is often better to simply drain the blister and leave the top of the blister intact to function as a biologic dressing. This will take slightly longer to heal than if you don't drain the blister.  However this assumes that you are of course going to continue to run, train and complete the marathon that you have planned.

It would be best to be evaluated in person or by a podiatrist or arrange a remote consultation with a running injury expert in order to get more detail, before making your final decision.  You can also learn more about blisters from running by clicking here.

Dr. Christopher Segler, DPM a marathon runner, podiatrist and 10-time Ironman Triathlon finisher who is is Board Certified, American Board of Podiatric Medicine.  He believes the best podiatry practice combines cutting edge technology with the old-school convenience of house calls. He makes podiatry house calls for runners in San Francisco, CA and Houston ,TX. He also does remote consults for runners who live outside of the United States. If you have a question, you can reach him directly at 415-308-0833. You can learn more about running injuries at www.DocOnTheRun.com 

I have Achilles Tendinitis and it hurts when I run. Can I do Yoga?

Hi Running Doc!

Question:  I have Achilles Tendinitis and it hurts when I run. I stopped running and have been trying to get the Achilles to heal. But I still want to exercise to stay fit and sane. I like Bikram Yoga. So my question is: can I do yoga without risking further injury to my Achilles tendon?
                        Thanks!
                        Aching Achilles in Berkeley.

Answer:  As a runner and sports medicine podiatrist, I firmly believe that injured runners heal fastest when they remain as active as possible.  This true for Achilles injuries as well.


The key with the Achilles tendon is making sure that the tendon is healing and that no further damage is taking place. Continued damage to the Achilles (such as repeated micro-tears) is what leads to tendinosis. Achilles tendinosis always precedes an Achilles tendon rupture.

In most cases of Achilles injury in a runner, there is a period of severely reduced activity. Sometimes a Platelet Rich Plasma (PRP) injection may even be necessary to stimulate healing. In the very worst cases, Achilles tendon surgery may even become necessary.

But once the injury is reversed and healing begins, it is important to get back to activity. If you are at the point where your doctor thinks the tendon is on the mend, it may be OK to add some Yoga to your routine.

With a healing Achilles tendon Yoga is mostly OK. However, there are a few Bikram yoga poses that are concerning, and should be avoided such as:
Garudasana (Eagle Pose)
Dandayamana - JanuShirasana (Standing Head To Knee Pose)
Dandayamana - Dhanurasana (Standing Bow Pulling Pose)
Tuladandasana (Balancing Stick Pose)
Tadasana (Tree Pose)
Padangustasana (Toe Stand Pose)

None of these poses are really likely to rupture the Achilles if done flawlessy. The problem is that if you have your Achilles completely taught (while attempting these poses) and then begin to lose your balance, it may be more than the tendon could take.

If you are doing Hatha Yoga, you should simply keep the risky poses mentioned above in mind and then sit out or modify any Hatha poses that your feel would put your Achilles in a precarious situation.

It is a great question! With any running injury the big trick is not just stopping activity, but being creative in identifying the activities you continue to keep the blood flowing, the mind calm and the healing in progress.

Dr. Christopher Segler, DPM is a sports medicine podiatrist and 10-time Ironman triathlon finisher. He is Board Certified, American Board of Podiatrc Medicine. His sports podiatry practice is limited to runners, triathletes and endurance athletes with complex injuries. He specializes in running injuries that don't heal with the conventional "just stop running" approach. His practice is unique in that he offers remote consultations all over the world via Skype. He travels constantly and is available to treat frustrated injured runners in person in both San Francisco, CA and Houston, TX. If you have an injury that isn't getting better, you can call him directly at 415-308-0833 or 713-489-7674. 

SF Tri Run Clinic: Foot Issues

Thanks to everyone from the SF Tri Club who joined us Monday evening for the Run Clinic. This was the second clinic in a series designed by Dino and Katie (our fearless Run Coordinators).

The point of the clinic was to discuss some of the keys to training that might help one avoid injury, particularly those running injuries that can wreck a triathlon season. We talked about running shoe selection, common training errors and barefoot running biomechanics.

There were many great questions from our Peeps. I will be posting those questions here, with answers, for all those who could not make to the Presidio Sports Basement for the clinic.

In fact, here's one now...

Question: What ARE the most common preventable running injuries?

Answer: The most common injuries I see in San Francisco runners and triathletes (that are preventable) are:
1. Stress Fractures
2. Achilles Tendinitis
3. Plantar Plate Injuries
4. Peroneal Tendintis
5. Sesamoiditis

See you out in the water, on the track, or on the road!

Dr. Christopher Segler is an SFTRi Club member, 10-time Ironman Finisher and Sports Medicine Podiatrist. He is Board Certified, American Board of Podiatric Medicine. His practice caters to active runners and triathletes in San Francisco, Berkeley, and Mill Valley. If you have a question about a running injury, you can call him directly at 415-308-0833.

Should I drain a liquid nitrogen wart blister?

Question:

I got a blister when I recently tried the liquid nitrogen treatment to freeze a wart on my foot. It is tender and so I stopped running. Should I try to drain the blister so I can run?

Answer:

The idea with treating a wart with liquid nitrogen is in fact to cause a blister. The way this treatment works is that when liquid nitrogen freezes the skin fluid collects between the dermis and the underlying subcutaneous layer of the skin creating the blister. The blister separates the skin layers. Here is how it cures a wart...

The wart is a thick callus covering an encapsulated collection of viral wart particles, which is within then the living layer of skin called the dermis. By creating a blister beneath the dermis (under the wart) the wart essentially gets lifted off of the underlying skin as the blister swells up.

The fluid within the blister will resorb over the next several days. As the blister heals and flattens out, it forms a scab-like structure that doesn’t fully re-adhere to the tissue underneath. Eventually the dried up skin of the blister peels off, and the wart goes with it. If all goes according to plan, you are left with new healthy skin underneath. 

There are many different blistering agents that can be used to cure plantar warts. Here are three of the most common wart treatments that work by blistering:

Liquid Nitrogen - creates a blister with a carefully placed frostbite-type injury. 

Bleomyocin - is a chemical blistering agent injected directly into the wart.

Canthacur - is a topical chemical blistering agent applied to the surface of the wart.

As every runner knows, blisters on the feet can be irritating enough to force one to limit their run mileage or stop running altogether. So it is not surprising that a runner may consider popping a painful blister to lessen the discomfort, promote healing and get back to running. 

This may be a reasonable strategy with friction blisters sustained during a marathon or other long run. But not so with warts treatment blisters.

The problem with warts is that they are caused by a viral infection of the skin. If you poke a needle through the blister (and through the wart containing all of those viral particles) you just might seed the surrounding healthy, non-infected skin with the wart virus. In this way, by attempting to drain the blister under the wart, you may actually infect other areas of the foot and cause a new wart to start growing nearby. 

Then, after the original wart (and its associated treatment blister) have gone away, you may have a brand new nasty little wart rearing its ugly head. Then you have to repeat this process all over again.

Another issue is that the fluid inside the blister is sterile. As soon as you poke a hole the blister fluid can drain out, but bacteria can also get in. So when you pop a blister the risk of bacterial infection goes up. 

If you have a wart that is being treated by a podiatrist, and the blister is large enough to interfere with your activities, you should follow-up with the treating physician. After all the doctor is being paid to treat the wart, so let the doctor finish what he started. Let your podiatrist decide whether or not to drain the blister, and do the draining if needed. That is the safest way to remedy the blister AND make sure that there isn’t any risk of causing a bigger problem long-term.

Heal fast and get back to running! 

Dr. Christopher Segler is a podiatrist who focuses on the rapid treatment of running injuries. He is a runner himself and 10-time Ironman Triathlon finisher. You can learn more about warts, blisters and running injuries at AnkleCenter.com and DocOnTheRun.com  If you have a question about a running injury, you can reach him directly at 415-308-0833.

Marathon Blisters Related to Pronation?

QUESTION:

Hi Doc,

I have just finished a marathon qualifier for an ultra coming up here in South Africa. I have always been pretty neutral footed, but with the tendency to pronate slightly. I have always had the odd blister after a very long run, but lately they seem to be worse and I am wondering if I am beginning to pronate more (can this happen over time?). I have taken a photo of some blisters that occur after a marathon. I don't like to get rid of them, I sorta let them callous for the season so its not so sore :-). Should I try pronation shoes? What are your thoughts? I use Nike Pegasus +28's. Really hope you can shed some light on this for me :-) 

Many thanks

ANSWER:

Blisters that pop up anywhere on the foot during/after a marathon are always the result of excessive pressure and friction. With excess friction the underlying layers of the skin begin to separate. Fluid accumulates and collects between the dermis and epidermis creating the fluid filled bubble that runners know as a blister. In the pictures here we can see that one blister has clear fluid and the other is dark. The dark blister implies that this is a collection of blood. This kind of blister is of course often referred to as a "blood blister." 

A blood blister insinuates more pressure or increased trauma, not just friction.

The location of the blister is important and helps a podiatrist figure out the cause. These blisters and calluses forming at the inside of the big toe joint. The medical term for this location is the "medial and plantar-medial aspect of the first metatarsophalangeal joint." 

All runners know the basic causes of blisters.  To be clear we will review:

1. Running shoes that are loose. The feet slide around with every foot strike and push off while running. The result of 26.2 miles of this is excessive friction producing blisters. 

2. Running shoes that are too tight. The feet are compressed against the inside of the shoes, increasing the risk of excess friction (with increased pressure) at parts of the shoe that move (such as the tips of the toes or ball of the foot where the break in the shoe occurs).  

3. Wet feet. Think twice about running through those garden hoses on the marathon course. Moisture in the skin can weaken the structure between the layers of skin, making blisters form with less friction that usually required. 

4. Starting and Stopping too much. If you are running with a walk/run approach, all of the starting and stopping actually takes more force (and produces more friction) than running at an even pace. This can increase your risk of blisters.  

There are other certain circumstances that can contribute to blister formation at the medial big toe joint. 

1. Pronation. As the foot pronates, the foot rolls inward, unlocking the joints in the mid-foot. The first metatarsal bone gets pushed up by the ground and the running shoe effectively twists right around the inside of the big toe joint. This of course creates excess friction and stimulated the formation of blisters during longs runs such as marathons. 

2. Bunions. Same forces at work as in excess pronation, with the added pressure at the bunion stick out and presses against the inside of the shoe. 

Solutions:

1. Blister-prevention socks that have 2 layers that can glide past each other. In effect, you beat up the socks instead of the skin.

2. Custom orthotics or over-the-counter inserts that support the foot, stabilize the subtalar joint and decrease pronation. If properly fitted and constructed, inserts can slow the pronation that contributes to the problem. 

3. Motions control running shoes. Stability running shoes decrease pronation with aggressive medial posting on a stable platform.  They are heavier, and stiffer. Beware-if you have high arches they can increase your risk of shin splints and stress fractures. 

4. Build mileage gradually. This gives the skin a chance to toughen up and form protective calluses without blistering.  

When in doubt. See a local podiatrist for a complete evaluation, running shoe analysis and gait exam to assess your running biomechanics. 

Dr. Christopher Segler, DPM a marathon runner, podiatrist and 10-time Ironman Triathlon finisher who is is Board Certified, American Board of Podiatric Medicine.  He believes the best podiatry practice combines cutting edge technology with the old-school convenience of house calls. He makes podiatry house calls for runners in San Francisco, Palo Alto, Sausalito, Pacifica, and Corte Madera. He also does remote consults for runners who live outside of the United States. If you have a question, you can reach him directly at 415-308-0833. You can learn more about running injuries at www.DocOnTheRun.com 

Today's View From the Run

Running in the San Francisco Bay Area is just amazing. Millions of people, but if you get off the main road, there is almost no one. Today at Crystal Springs, just a handful of runners and a placid dear enjoying the perfect weather. 

I love running. And I love California!