The Z-value, also known as the DIN setting according to ISO Standard 11088, is the safety release value for ski bindings. It is displayed on the toe and heel units of the binding and may vary depending on individual ski boot characteristics. The Z-value determines at what torque the binding should release to minimize injury risk.
All modern ski bindings are designed and tested according to the following international standards:
These standards ensure that release values correspond to biomechanical tolerances and minimize the risk of tibial fractures and ligament injuries.
The binding is engineered to release when the torque applied to the lower leg exceeds a defined threshold. The Z-value is a dimensionless number that increases proportionally with the required release force. Muscle or ligament strain is not part of the calculation; only the torque acting on the tibia is considered.
There are two officially recognized methods for determining the correct Z-value:
Both methods are based on the statistical average body proportions of the Eurasian population. Age influences bone density, and gender differences also play a role — women typically have a finer bone structure than men. These factors are incorporated into standardized Z-value tables to provide safe and reliable binding adjustments.
