CONTOURED DEEP HEEL CUP

What is a good heel cup and how it contributes to foot comfort 

Cupping the heel reduces pressure by redistributing the body’s weight over a greater surface area on the sole of the foot.  Improving pressure distribution improves foot comfort. 

 

Many insole companies claim to have heel cups on their replacement insoles, but in reality most replacement insoles have only a small lip (5 mm).  Realistically little if any cupping of the heel can take place with a small lip.  Functionally such a small lip would not provide any noticeable decrease in pressure over a flat insole and therefore would not add any comfort.
As you can see from the example insole above left, the typical low heel cup provides less contact area (red line) than the insole at right, which has a deep heel cup and much more contact area to reduce the pressure.

NO HEEL CUP

HEEL CUP
GREATER PRESSURE
Less Comfortable  

REDUCED PRESSURE
 More Comfortable

The F-Scan® images above show how a good heel cup can reduce high level (red) peak pressure.  The two F-Scan images (stacked) above left are of an original equipment insole without a heel cup (5mm lip).  Notice the high pressure (red) in the heel area.
 
The two images above right were taken using the same shoe, but using a rigid plastic heel cup w/o any cushioning.  The higher pressure (red) area has been reduced to a lower pressure (orange, yellow, green and blue).  This significant decrease in pressure translates into increased comfort for the wearer.
Just as importantly as being extra deep, a good heel cup must have the correct anatomically contoured shape in order for the foot to get the maximum benefit.  Birkenstock shoes are a good example of an anatomically contoured heel cup. 

A good heel cup naturally increases the cushioning by helping contain the area under the calcaneus, commonly referred to as the “fat pad”.  By keeping the “fat pad” positioned underneath the heel area and not allowing it to flatten out, the heel of the foot has more material beneath it to cushion itself better.  The secret is keeping the heel of the foot in a round as opposed to flat shape.