Maintaining your Feet
Boots
There is no one best type of boots. All have their advantages and disadvantages.
Waterproof / Breathable versus Ventilated
Waterproof or Breathable boots such as those lined with Gore-Tex® keep feet warmer in cold environments. But in hot environments your feet can sweat faster than the liner lets water escape. When feet stay damp, they are more vulnerable to fungus such as athlete's foot. Damp skin is also softer, and more susceptible to blisters and being rubbed raw. Waterproof or breathable boots are preferable in cold environments and with less exertion, but fully ventilated boots are better with more exercise and in hotter areas.
Below versus Above the Anklebone
High cut boots keep your feet warmer, discourage dirt from migrating inside, and keep you from banging your anklebone against rocks. If they are also stiff, they may keep you from rolling your ankles, and they make kicking steps in snow easier.
Low cut boots do not rub on and bruise the skin above your anklebone. They are cooler and better ventilated. They allow more flexibility when walking rough routes or climbing. Low cut boots are lighter and easier to walk in, assuming the terrain is not rough. On the downside, they tend to collect rocks and dirt and offer no ankle support.
Stiff versus Flexible
Stiff boots are necessarily cut above the ankle. They keep you from rolling your ankle by pushing on your leg above the anklebone. This can cause bruises and rashes. A stiff boot allows you to kick and cut steps in hard snow easily. Flexible boots glance off hard snow, making it more difficult to kick an effective step. Furthermore, a stiff, hard edge on a boot allows you to stand on a very narrow step on rock or groove kicked in snow, where a flexible boot would flex and roll off the support. Stiff boots allow you to stand and walk on sharp rocks without them digging into your feet. Stiff boots are better for crampon use. Stiff boots usually require some break-in before extended use.
Flexible boots often can be used with no break-in. They don't push on your foot to force it into the shape of the boot. Places where stiff boots push your foot into place are prone to bruising and blistering. Flexible boots are usually lighter than stiff boots. Some flexible boots are better ventilated than stiff boots.
Allow for Foot Growth
Feet may swell in volume somewhat, particularly early in a hike or after an injury. Also, the muscles, tendons, ligaments, and etcetera which hold your foot in an arch shape relax somewhat after long hikes with heavy weights. This causes the foot to lengthen and broaden. Therefore, a shoe which fit well before a long distance hike may be tight across the ball of the foot or against the toes a week or two into the hike. It may be necessary to switch to shoes one or two sizes larger to control bruises, blisters, and blackening toenails.
Different Brands Fit Differently
Each brand of boots uses a different last, or shape of foot, to design and make their shoes. Trying different brands to find one that fits your foot is a good idea.
Socks
There are many types of socks that various hikers like. Every individual has different problems, or no problem at all.
The first universal bit of advice I have, is that if you have no foot problems, your socks are fine, and I wouldn't go spend a bunch of money trying new types. But if you do have foot problems, think about your socks...
Wrinkles and Seams
The second universal thing about socks is that a wrinkle inside your boot is bad. A wrinkle or a seam that presses on your skin is likely to cause blister or rub right through your skin. Whatever sock you choose should have the right geometry and snugness so that it doesn't wrinkle inside your boot, even after hiking all day.
If your socks seem to fit right at first, but become baggy later, consider how much elastic material is added to the sock fabric. Stretch nylon, spandex, or other elastics in small percentages help the sock to return to its proper shape time after time. Note that bug repellants such as DEET destroy some elastics, so if you're getting baggy spots in your socks or other elastic garments, being more careful with where you apply the DEET may help.
Ankle Socks versus Knee Socks
One of the primary jobs of socks is to slide freely along the boot so that your skin is not sliding against anything. Socks need to be long enough to prevent this rubbing. Sliding skin leads to rub throughs, blisters, etcetera. So if you wear low cut socks and high cut boots, the upper part of the boot may rub against the skin and cause problems. And if you wear gaiters and they cause rubbing problems, you may want a sock long enough to peek out the top of the gaiters. Longer socks may also keep your legs warm and keep branches and rocks from skinning your legs.
Shorter socks, on the other hand, don't hold as much heat in. They are less likely to collect burrs and stickers while walking through weeds. They weigh less.
Sock Fabrics
Cotton is a poor choice for long distance hiking socks because it absorbs and holds water. Moist feet may lead to blisters, skin rub through, and fungal infections.
Wool stays thick and cushiony better than synthetic fibers. It is a good insulator. Merino wools are less stratchy than other wools. Wool alone tends to get baggy and prone to wrinkling; adding some percentage of synthetic and elastic fibers to the wool helps to maintain snugness and fit.
Synthetic socks dry faster than wool. Some are made to be thin and slippery, others to be thick, cushiony, and to insulate against cold.
Silk socks are made to be thin and slippery. Silk is not as durable as other sock materials.
Thick Socks versus Thin
Thick socks provide more padding. If impact below the heel and ball of the foot seems to be hurting your foot, thick socks, or hybrid thick-thin socks, padded under the heel and ball, but thin elsewhere may work. If extra space inside the boot seems to cause problems, thicker socks may take up the space. Thicker socks provide more insulation, nice in colder environments.
Many hikers wear thick socks even in hot environments, because they like the padding. The extra insulation does not cause too much of a problem because the feet are only a small percentage of body area. So as long as the rest of the body is dressed for cooling, wearing warm socks is compensated for. In areas with dark soils and beating sun, a hot layer of air forms along the ground, and insulating socks can keep some of this heat from entering through the feet.
Thin socks are nicer where there is not much space between the boot and the foot. A thick sock here would compress the foot and cut off blood circulation. Thinner socks trap less heat.
Sometimes, multiple thin socks or a thin and thick sock are used together in the hope of creating multiple sliding surfaces to prevent chafing of the foot. In this case, the thin socks, especially those next to the skin, are known as sock liners. This system only works if the various layers actually slide against each others. To test this, hike for several hours and then pull the socks off/apart carefully. If you observe that the socks stick together, this system won't work as it is meant to. If they slide right apart, perhaps it will. Note that if you wear several of the exact same type of sock, the seams will stack atop one another. If the socks form wrinkles, the wrinkles may stack up too. So make sure that the seams and wrinkles are not at the part of your foot that has problems. Or use different types of socks so the wrinkles and seams don't stack up.
Note that if you use an especially thick or thin sock or system of multiple socks, you may need larger or smaller boots so that the whole system fits correctly.
Dirty Socks
Where trails are dusty, sandy, or gravely, shoes and socks tend to accumulate dirt. Some mineral soils have been tumbled in streams, and the dirt particles are rounded and smooth. Others have very sharp particles. Walking around with a shoe full of sharp dirt can wear through the soles of expensive socks in a matter of days. Wearing higher boots or gaiters can keep some of the dirt out. Emptying your boots when you stop to rest, etcetera, can help. Washing socks regularly can extend their lives.
Blown Sock
Even if the bottom of the sock is completely blown out, it may be wise to continue wearing it. It may protect the top and sides of your feet from wearing through or blistering.
Gaiters
Gaiters wrap around the shoe and leg. They keep snow and dirt from falling into the boot, and depending on the material and height, may insulate the leg, prevent sticks, rocks, and crusty snow from scratching the leg, and prevent snake bites, etcetera.
Some gaiters have a stirrup strap that loops under the boot to keep the gaiter pulled down around the boot. This strap wears as you walk over rocks, gravel, etcetera. A few inches of tubular climbing webbing can be slipped over the strap to control this wear.
Short, stretchy gaiters keep dirt, rocks, and snow from falling into the boot, and keep burrs and stickers from accumulating in socks.
Longer gaiters of thicker, heavier fabrics prevent sticks, rocks, and crusty snow from scratching the leg, and, if thick enough, may prevent snake bites, etcetera.
If gaiters are injuring the skin by rubbing, or if you want more insulation against the cold, socks the full length of the gaiter may be in order.
The top of an old long sock can be cut off to make an improvised gaiter. If it fits well around the leg and you somehow keep it down around the shoe, it can keep rocks and snow out of the boot.
Athlete's Foot
Athlete's foot is an infection of the skin by fungi such as Epidermophyton floccosum, Trichophyton rubrum or T. mentagrophytes. When it occurs between the toes, or interdigitally, the skin can flake, peel, and crack until it bleeds. This is painful and can lead to more complicated infections. The same fungi can infect other skin areas of the foot and body, in which case it is known by other names. It is transmitted by shower floors, towels, and other damp things that touch an infected foot and then yours. It thrives on wet, warm skin, and hot sweaty feet in boots are perfect environments. It can be fought by keeping the skin drier and by using over the counter antifungal powders and creams. If you notice and treat it before it gets serious, it may not get to the painful or bleeding level.
Blisters
Blisters are caused by skin rubbing back and forth in tight areas of shoes. Blisters can be avoided by properly fitting shoes, by keeping feet dryer, and by reducing friction between the skin and the shoe.
Bigger Boots?
Particularly in the first few weeks of a long distance hike, feet can grow in their length and in the width of the ball of the foot. The great amount of walking, over a hard surface, and with high pack weight, causes muscles, tendons, ligaments, and etcetera, to stretch, flattening the arch of the foot and generally allowing the foot to spread out. So even though the boot may have been comfortably roomy before the hike, a few weeks into the hike it may be too tight. It's not surprising when feet grow one or two sizes over the course of a hike.
Sweaty Feet?
Blisters are more likely to occur on feet damp from sweat. It may be helpful to take the shoes and off and let the feet, boots, and socks dry several times per day. A sunny, breezy spot would shorten the drying time. Socks and insoles can be hung on a bush in the sun. The boots can be lined up so sun shines into them. The toes can be held separated in the sun to allow drying between the toes. Drying the feet like this will also help control athlete's foot and is an excellent opportunity to do a full foot inspection (below).
Tape the Blister?
Blisters, skin, and boots can be taped to reduce friction between the skin and boot. Moleskin® is an adhesive felt that is placed over a blister or a place that is rubbing and you are worried that a blister may form (a hot spot). Moleskin® is thick and may increase the pressure between the boot and the skin, worsening the problem. Sometimes the thickness is used to advantage by cutting out a donut or toilet seat shaped ring of Moleskin® so that the fluid filled blister is surrounded by the thick ring. This may keep the pressure of the boot off the fluid filled blister. Unfortunately, it would increase the pressure on the skin under the donut. Certain medical tapes have a very slick surface. Since they are much thinner than felt, they don't increase the pressure between the boot and the skin as much. I prefer tape over felt. Whether using tape or felt, place a strip parallel to the direction of the rubbing, and extending beyond the hot spot. Otherwise, the friction and rubbing may cause the tape to roll up and come off.
Boots can also be taped. Duct tape has a slick outer surface, and will allow the socks to slide with the foot. The tape can be bonded to the inside of the boot adjacent to hot spots. Duct tape has an acetone based adhesive. If bonded to skin, it may cause a rash. If so, switching to medical tape or Moleskin®, which have hypoallergenic adhesives, may help.
Drain the Blister?
Blisters are usually filled with a clear serum or plasma. If the filled blister does not cause discomfort and the fluid remains clear, it can be left intact. This will reduce the chance of infection. If the blister becomes infected, the puss should be drained. If the fluid inside the blister is not clear, or if the surrounding skin is red, swelling, or hurts, the blister is infected. A small hole in the blister envelope can be cut with scissors or a fingernail clipper. This has the advantage over a hole poked with a pin or needle that it won't close up later.
Some people run a needle and thread through a blister, and leave the thread in place. This technique keeps the inside of the blister moist, while the thread allows germs to enter, and harbors the germs inside the blister. The needle and thread technique is not recommended as it is likely to cause infections.
Sweaty, dirty feet are an environment prone to infections. All blisters and other foot wounds should be inspected regularly for infections. Puss, swelling, pain, redness, and warm feeling skin are signs of infection. If infections can't be controlled in the field, it's time to get off the trail for a while and see a doctor. Red streaking from the wound towards the heart indicates that the infection has crossed from the wound into the lymph and blood. This could be deadly, and you should seek medical attention immediately.
Chafing
Even if a blister does not form, skin can chafe or rub all the way through until it bleeds. Wet skin is more likely to chafe through than dry skin. As with blisters, pressure and rubbing cause chafing. To fix chafing, keep the skin drier, solve the shoe fit problem, and / or tape the skin or boot as you would for a blister.
Foot Inspection and Maintenance
It's a good idea to thoroughly inspect your feet every day or two. Toenails should be kept cut back so they don't hit the front of the boots and cause bruising or worse, and so they don't cut into socks. Look between the toes for any sign of athlete's foot. Treated early, athlete's foot can be cured before any painful cracking. Look for any blisters and hot spots. Early taping can prevent the blister or limit its growth. Any cuts or wounds should be monitored because the dirty, sweaty environment inside the boot is conducive to infection. Cracks on the heel or elsewhere can be treated by filing or moisturizers.
Cracked Heels
With all the walking that long distance hikers do, it's not surprising that many build up thick calluses on their feet. Calluses are dead skin. In very dry circumstances, they become brittle, and crack easily. These cracks can be very painful, bleed, and get infected.
Cracks start because the skin is dry and brittle. Hikers may have extra dry feet in arid environments when using sandals or well ventilated shoes. Using an oil based moisturizer or balm can keep the callus soft and pliable, avoiding further cracking.
The thickness of the callus can be reduced with a pumice stone or foot file. This is the only fast way of reducing the depth of a crack.
It may be possible to tape a crack closed to limit pain or bleeding while getting to a town to fix the problem.
Plantar Fasciitis
Plantar Fasciitis (PF), Plantar Fasciopathy or Jogger's Heel is a painful inflammation, fibrosis, or structural deterioration of the plantar fascia. The plantar fascia is fibers that originate on the medial tubercle of the calcaneus (heel bone) and extend towards the toes. It supports the arch of the foot. In long distance hiking, the much greater amount of walking and the much greater pack weight may overload these tissues. Some damage and some swelling may occur. Pain on the bottom of the heel, especially if it most intense during the first steps of the day, or the first step after a long break, may be due to Plantar Fasciitis. Dorsiflexion, or stretching the foot so the toes approach the shin, may be difficult due to tightness of the gastrocnemius muscle or the Achilles tendon. Such stretching may increase the heel pain.
Heel Spur
A Heel Spur, a small bony calcification on the calcaneus (heel bone), often forms when people have Plantar Fasciitis. Pain is often due to the Plantar Fasciitis rather than the Heel Spur.
Shin Splints
Shin Splints, Medial Tibial Stress Syndrome (MTSS), or Tibial Periostitis is damage to the connective tissue of the tibia, and it causes pain between the knee and ankle. Damage may be increased by walking uphill, downhill, and on uneven or hard surfaces. A dull ache or pain and swelling may recurr along the lower two thirds of the tibia. As with Plantar Fasciitis, pain may be highest in the first steps after long rests and diminish with continued walking.
Trench Foot or Immersion Foot
When feet have been wet and cold for days, they may develop Trench Foot. The soles of the feet become extremely sensitive to pressure: Just plain walking can be excruciatingly painful.
This happened to me while walking Offa's Dyke Path, which more or less follows the border between Wales and England. The soil and grass were so wet that often stepping down would squeeze out a pool of cold water as though I had stepped on a soaked sponge. This happened enough times per day that my boots and socks were always soaking wet. And since the humidity hovered near 100% around the clock, my feet never dried at night. After 4 days my feet hurt so much I could barely walk.
Fortunately, in the early stages of immersion foot, just keeping feet warm and dry for a day may completely resolve the symptoms.
On Offa's Dyke, I checked into a B&B early in the afternoon, took a shower, and layed around my warm, dry room barefoot until 10am. I went from hobbled to completely cured just by staying warm and dry for a long night.
Left untreated, blisters may form, and skin and tissue may die and fall off.
Informative Book
Fixing Your Feet: Prevention and Treatments for Athletes by John Vonhof is a book with a huge list of problems atheletes have had with their feet and the solutions they used.