The inserts trademarked as Killer Heels Comfort are inserts for high heels that have a function to stop the foot from moving, and thereby prevent pain. They also provide the traditional function of cushioning under the ball of the foot.
The inserts are in two parts thereby ensuring a perfect fit, and allow them to function as they were designed.
They are the only insert that is made from shaped Poron, rather than flat pieces of Poron. The shape physically stops the foot from moving forward at two places. There is very little room inside a high heel shoe, therefore the inserts have to be very small but need to be strong enough to withstand hundreds of pounds of pressure without flattening. . They are small so they fit entirely underfoot ,yet are able to stop the foot from moving laterally, and also to provide cushioning under the foot.
The material that they are made from is a polyurethane called Poron. This material does not get crushed when pressure is applied on top of it or pushes on it from the side. This makes it ideal for stopping the forward push of the foot at the front of the heel and the front of the ball of the foot.
There are 3/4 length insoles sold that are made from gel that function to prevent foot pain by increasing the size of the heel area of the shoe so that more weight is kept on the heel and less on the forefoot. This function is the same that Killer Heel Comfort inserts also do. Killer Heels Comfort provide a physical barrier at the front of the heel that prevent the forward movement of the foot. Several features differentiate these inserts and make them better . They prevent sideways movement of the foot with a small indentation design in the edge of the front of heel insert, they also don't raise the foot under the heel or create a rounded slippery surface under the heel so that the foot slides sideways in all open shoes.
The science behind the design of Killer Heels Comfort high heel inserts is physics, specifically Newton’s First Law of Motion. This law states that “every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it”. In high heels the foot moves forward until it is stopped either by inserts without pain to the foot or by the front of the shoe with pain to the foot.
The high heel inserts design that stops pain from starting is the best ways to make high heels more comfortable because by eliminating the main source of discomfort - which is the forces of the front and sides of the shoe putting pressure or 'external force' on the foot is the source of most of the pain in the forefoot.
The inserts stop the foot from sliding forward at two places, which are at the front of the ball of the foot and at the front of the heel where there are vertical surfaces.
Putting inserts into high heels is very different from flat shoes. In high heels the inserts must function on vertical surfaces plus take up very little room. The inserts help the foot to 'stay put' on a ramp that is inclined from between 15 and 30 degrees. Unlike inserts or insoles for high heels that go under the heel of the foot to help them stay in place, the inserts are held in place with strong two sided tape. The inserts do not add any height under the heel. Height added under the heel of the foot forces the foot upward and destabilizes the foot by raising the center of gravity of the wearer's foot. Destabilizing the shoe if it is a high heel is dangerous for the wearer as the wearer could fall off the shoe.
In a closed shoe the foot stops when the front of the shoe's toe box crushes the toes and the sides of the shoe force the bones of the forefoot to pinch together. When this happens a gap appears between the back of the shoe and the heel.
In an open shoe the forward slide of the foot makes it cut into sandal straps at the sides of the foot, the toes overhang at the front, and the sling back of a sandal style shoe falls down when the heel moves forward in the shoe.
When the foot is stopped from sliding inside heels the customer can buy a properly fitting shoe without fear that a shoe that allows for the proper half inch of space in front of the longest toe will not stay put. Killer Heels Comfort high heel inserts function best in properly fitted heels. They are also the ideal high heel inserts to 'rehab' shoes that have become too roomy due to becoming stretched out from being worn a lot or that are slightly big because they are between sizes.