Blisters are a product of friction.... often referred to as shear force friction. The skin of your foot, and the sock that is in contact with that area of skin, are sliding and rubbing together.
Strategies for the prevention of shear force friction have changed and matured over recent years.
- A properly fitting shoe. In brief, it needs to be long enough and wide enough to accomodate any insoles, orthotics, metatarsal pads, etc, PLUS the socks that you will be wearing, PLUS the increased pressure on the feet from wearing a loaded pack.
- Light padded Merino wool sock designed for walking or backpacking, or the same type of sock in a good synthetic blend. A heavy pad on a sock allows potentially more movement against the skin, takes longer to air out, and takes longer to dry when washed.
- A sock fit that is snug. Not excruciatingly tight. You want the shear force to be between the sock and the interior of the shoe, not the sock and the skin. A snug fitting sock will help to make that happen
- Allow the sock to move a bit in the shoe. By keeping the shoes a bit looser on the feet, the sock will take the brunt of the shear force. If a shoe is tied snug, then that forces the foot to move more in the sock, which means the sock and skin are absorbing the shear force. An exception occurs on long downhill grades; the shoes need to be tied tight enough to keep your toes from hitting the front of the shoe which can cause injury and trauma to the nail bed and toe joints.
- While there are foot lubricants, from Body Glide and Hiker's Goo to plain old vaseline, the have a fairly short viable working span as the material rubs of the skin and is absorbed by the socks. For prophylactic protection from shear force friction, a long lasting barrier is the better option. The placement of tapes, like Leukotape P, or moleskin-type products, if adhered correctly, will last the whole day. You clean off the area of application with a bit of alcohol to remove grease, dirt, and body oils; cut a piece of your chosen barrier material to fit the area you want protected; be sure to cut rounded corners rather than square in order to help the material from rolling up away from the skin; place the barrier on the area, taking care to not handle the adhesive; spent a bit of time rubbing the material to create friction so that the adhesive will heat up and adhere more firmly; at the end of the day, remove the barrier and use some alcohol to wipe the area that was covered.
As to the thought about boots and ankle support:
First, unless there are medical issues, the ankle is best protected with exercise and use, where the ankle is allowed to use uneven surfaces, exercise, and balancing on one foot in order to build strength and endurance and lessen susceptibility to injurious fatigue.
The only sure ankle support for medically indicated need are ankle braces which can fit inside of the shoe. Despite anecdotal evidence and subjective opinion to the contrary, research has repeatedly shown that boots do not provide the level of stiffness and the shear rigidity needed to keep ankles free from injury.
They can, in fact, exacerbate the risk of injury. A foot in a boot is sitting higher off the ground than when in a shoe because the outer and midsoles are much thicker and built up. Additionally, the outer sole of boots are trimmed closer to shell of the boot, meaning that the outer sole has a fairly narrow profile. Both of these factors have been shown to have a higher risk of the footwear 'rolling' when stepping on an unstable surface or piece of debris like loose rocks or uneven surfaces.
As the boot begins to roll, the boot carries the foot with it, the higher material of the boot above the ankle exerts more force against the foot to make it roll with the boot. That material is not stiff enough to keep from flexing, which means that your ankle is going to start bending as the roll of the boot continues. And because the foot is higher off the ground inside the boot, the ankle can be forced into a more significant bending.
Another factor about boots that helps lead to injury is their weight. The heavier the weight that the foot and lower legs need to lift, the more stress and fatigue the ankles and supporting structures are exposed to. Such weakens the ability of the ankle structures to maintain resiliency.
Trail shoes and trail runners, on the other hand, do the opposite when confronted with the same type of uneven surface or debris. The outer and midsoles are much closer to the ground. They are also wider than the shoe making for a contact point with the ground that is more stable. Their much lighter weight keeps ankle structures from fatiguing.
Now here is the thing researchers found as most significant: A foot in a shoe that is kept a bit loose can compensate, to a large degree, when the shoe starts to roll off of an uneven surface. As the shoe rolls, the foot tends to slip around the shoe. In other words, the shoe moves
around the foot for the most part, so the ankle won't immediately bend out of place with the shoe. This allows the wearer of the shoe to have enough time to react to the rolling and twisting shoe to keep the ankle from injurious strain.
Yes, there are people who get ankle injuries in trail shoes and trail runners. But those injuries are less frequent and less severe, on an average, than with a foot encased in an above the ankle hiking boot.
As I stated above, there will be any number of folks that, with no predisposing medical conditions, will state anecdotal evidence along the lines that they, or a friend, or other family members, et al, were saved by above the ankle boots. Subjective opinion is like that.
But objective evidence begs to differ on the best way of protecting ankles from injury.