It goes about this in three ways. Impact protection saves your feet when impacting the road or whatever you are crashing into. Some kind of armor is needed to reduce the force that your foot has to deal with. Abrasion protection prevents the loss of skin and tissue that happens when your skin and flesh slide along the road at speed – some – things human bodies clearly aren't designed to do. The motorcycle boot must have materials that resist abrasion as well as closure systems that keep the motorcycle boot on your foot. Sneakers are singled out because even leather sneakers, which maybe give some abrasion protection, have problems staying on the foot meaning the overall abrasion protection is effectively zero.
Finally, there is hyperextension prevention. Hyperextension implies a joint being forced to move in a configuration it isn't designed to handle. Example could be your toes stuck under the motorcycle while you keel over backwards. Or an impact that forces your instep up so that it comes into contact with your skin. Both are unnatural movements that are sure to cause structural damage. Motorcycle boots feature a number of systems that are designed to prevent motion in the usual direction but not in other orientations. This can also make them uncomfortable for anything but riding a motorcycle...
Basic Motorcycle Boots StylesMotorcycle boots fall into four categories. Sport motorcycle boots feature sliders, armor, plastic molding and other elements which gives them a loud, technical appearance. These are also the most protective and the most expensive motorcycle boots. Street motorcycle boots have some protection but it is kept-low-key so that the appearance is casual. These can be comfortable off the motorcycle but protection levels have to be traded in for the look as well as the more affordable prices. Cruiser boots blend protection into a retro-style leather boot. Fourth and final are other boots, including off-road and motocross boots that are rapidly evolving into niches. We aren't going to cover motocross boots in any great detail in this article.
The height of the motorcycle boot is actually a bigger consideration that style in protection terms. The basic is over the ankle. In fact, if you're using any boots on your motorcycle, you should make sure they are leather (which is more abrasion resistance), rise to above the ankle, to protect the ankle bone and less likely to slip off in a crash, and have a secure closure system – if it's a lace-up, then lace them up like you mean it and tuck the lose ends away.
Short Motorcycle BootsShorties, or short motorcycle boots rise to just above the ankle – the minimum height you want from a motorcycle boot. This protects the exposed ankle bone and makes the shoe harder to dislodge in a crash. The shorty then is the least protective motorcycle boot style and most likely to look casual. Now there are sporty styles too. In case, the job of protecting your skin falls to your pants. It's not a trade-off I am comfortable with but I know a lot of people, including colleagues who use short motorcycle boots daily.
Mid-Height Motorcycle BootsThe mid-height motorcycle boots rise to the middle of the shin – most cruiser boots and touring boots. These are very comfortable, easy to get in and out of and there is protection without the bulk of a full height motorcycle boots.
Full-Height Motorcycle BootsA full height motorcycle boot rises pretty close to the knee and the overlap between knee and armor and skin or tibia plate is significant. The height makes these the most protective of the motorcycle boots and makes them nearly impossible to come off during a crash.
A full height motorcycle boot will usually feature substantial armor that will cover the entire Tibia leaving an accordion-style flex panel to allow bending just about the ankle. Closure systems can vary but these boots are usually the hardest to get in and out of. You'll get used to them, but wearing them daily requires commitment.