Bicycle Helmet Safety Institute

Consumer-funded, volunteer staff

Helmets Children Promotions Statistics Search

The Helmet Update

Volume 36, #4, May 29, 2018

All issues index

Testing by two Snell officers shows no performance gain with MIPS

Clarification added on May 31, 2018

This is a clarification to our Update of May 29:

We have revised our conclusion about the Snell officers' research. Although we still think it is a most significant assessment of the performance of the MIPS system to date, the testing did not cover the whole range of crash scenarios where a slip plane could possibly be helpful. We should have pointed out that other lab testing using an unrestrained moving headform with a sticky rubber covering and no neck attached impacting a very rough 45 degree slanted anvil with the straps tight over an inflexible jaw (the configuration MIPS uses) has shown that MIPS does reduce rotational acceleration in that particular case. We still think your helmet, with a normal scalp under it, will move anyway.

Do you need MIPS? Using careful evaluation, and in light of the Snell officers' testing showing no benefit in their test configuration, we are still not convinced that you do. It probably won't hurt, other than any effect on ventilation, of if your manufacturer has kept the same outer profile and reduced the thickness of the normal liner to accommodate the MIPS layer, or if it lets the helmet slip too much, or if the extra cost of the MIPS model makes a difference to you. We do not see compelling evidence that you should trade in your current helmet on a MIPS model unless having the Latest Thing is important to you. We have not done so. Despite this research we think the jury is still out on MIPS.

Here is a clarification on the testing provided in March 2021.

Here was the original Update:

On May 23 the Snell Foundation's Bill Muzzy presented to ASTM's F08.53 subcommittee the results of Snell testing of MIPS (Multi-directional Impact Protection System) performance using a linear impactor and offset (oblique) impacts. Two Snell officers working on a test method for rotational injury tested a MIPS and non-MIPS version of the same Specialized helmet. Their results with full details will be published in a journal soon.

The two dropped a 5kg guided impactor onto a helmeted Hybrid III headform and neck, impacting the helmet sides to achieve an oblique transmission of energy. The MIPS layer activated and moved. They used both flat and hemispheric impactors, and measured both linear and rotational acceleration. They hit each location twice. Helmet straps were tight.

Data from the tests showed no significant improvement in the MIPS helmet's performance over the non-MIPS model. In some cases the non-MIPS model performed better.

The MIPS representative present at the ASTM meeting, Peter Halldin, said that he was not surprised, since their own testing with linear impactors had the same result, and they don't know why. (MIPS normally tests with vertical drops on a slanted anvil.)

We have a page up with more background.