Does Heel Counter Stiffness Matter In Shoes?

This month, I want to discuss the heel counter stiffness test, look at some of the literature that is out there and what it says about whether heel counter stiffness really makes a difference in controlling foot function in a shoe.

In 1992, Stacoff and colleagues stated the following about the heel counter in shoes: “The movement of the heel counter and of the heel inside a running shoe is similar but not identical. The heel inside the shoe moves by a smaller amount and more slowly. This may be regarded as a protection of the rearfoot due to the shoe.”¹ 

This definitely sounds like a positive vote for the heel counter’s ability to control the rearfoot. However, a few years later, in 1995, Van Gheluwe and coworkers determined that “the results showed that only the more rigid shoes tended to create significant differences between calcaneal and shoe heel eversion during ground contact, except close to heel strike. The rigid shoe thus resisted eversional forces. The calcaneus, however, was not prevented from slipping within the shoe and from everting as much or nearly as fast as in a shoe with a more flexible heel counter.”²

This study seems to suggest that maybe the stiffer heel counters slow things down but the calcaneus was still able to slip in the shoe and evert, but not quite as fast as in a shoe with a more flexible heel counter.

A more recent paper from Alcantara and colleagues studied whether calcaneal motion matched shoe marker motion, and whether support shoes would control that motion better than neutral shoes.³ The need for the shoe holes, or cutouts, was so that the foot markers could be fully visible during kinematic testing.

These authors found that “Shoe markers significantly underestimated calcaneus ROM across all planes of motion. Additionally, the required modifications to the shoe's heel had no effect on tibia ROM in the transverse plane.” Alcantara and coworkers also determined that the shoe modifications they utilized in this study did not affect the overall support of the shoes.

Obviously, there is some mixed messaging here. Ultimately, two of the papers support the fact that more than likely, a shoe’s heel counter does not seem to decrease overall calcaneal motion. The support built into shoes, meaning single or dual density EVA, does seem to have some effect on the motion of the calcaneus, but still does not slow the calcaneus in the shoe to the extent that it slows the markers on the shoe itself.

Ultimately, it appears that heel counters may affect some of the calcaneal pronation motion but probably not all that much. It does seem from the last paper by Alcantara and coworkers that tibial motion is almost not affected at all by heel counter stiffness.³

Does this mean that we should stop encouraging patients to test for heel counter stiffness? Maybe or we might suggest to them that moderate to high stiffness heel counters likely do similar things, but will do more than the least flexible heel counters.

Ultimately, the foot is going to continue to move in the shoe regardless of the shoe’s overall stiffness properties. This is not always a bad thing as some feet need a little bit more opportunity to move or pronate, but some feet do need to be slowed down and/or have decreased pronation.

Once again, this just lets us all know how much we may not know about how shoes really work, and that we always need to keep learning.

References
1.    Stacoff A, Reinschmidt C, Stussi E. The movement of the heel within a running shoe. Med Sci Sports Exerc. 1992;24(6):695-701.
2.    Van Gheluwe B, Tielemans R, Rossen P. The influence of heel counter rigidity on rearfoot motion during running. J Appl Bomech. 1995;11(1):47-67.
3.    Alcantara RS, Trudeau MB, Rohr ES. Calcaneus range of motion underestimated by markers on running shoe heel. Gait Posture. 2018 June;63:68-72