What Is the Shoe Liner Test? How Do I Interpret It?

The Shoe Liner Test is an important measure of how foot-healthy a shoe is and whether or not the shoe will accommodate natural toe splay (preferably enabled by Correct Toes). Ideally, we want to see the foot (with Correct Toes on) exist fully within the margins of the shoe liner. And that's the case most of the time for the men’s and women’s footwear we feature on our site. In some cases, however, there may be a small amount of liner spillover, usually involving parts of the big and little toes. As long as the spillover is not excessive, this can actually be okay if the following two conditions are met:

1. The shoe has a sufficiently soft and expansile upper (such as the upper of the Lems Primal 2 shoe)
2. The shoe's toe box exhibits some curvature (i.e., outward bowing) in its sidewalls

These two design features can, in many cases, accommodate a small amount of liner spillover, so it's important to keep this in mind when performing the Shoe Liner Test on your own shoes. Though it's also important to consider how your foot feels inside the shoe, for most people (especially those who are accustomed to having their toes squished inside conventional footwear), it can be difficult to accurately assess toe box width and whether or not there is any toe impingement occurring. One of the virtues of the Shoe Liner Test is that it asks you to rely more on your eyes and on objective findings than on the subjective feel of the shoe on your foot.

For those who experience a small degree of liner spillover, you can also consider permanently removing the liner to create a bit more space for your foot and toes inside your shoe.