Objective The objective of this study was to investigate the need for an updated specification for improved Downhill and Super-G helmet. One important aspect was to understand if the impact situations in the ski slope can generate high rotational accelerations and if so, how can the helmets be designed to absorb both translational and rotational energy.

Design TV footage from 11 accidents during 2008–2010 has been collected by NIH, Oslo. Video analysis of the accidents has been conducted by KTH to quantify the kinematics of the helmeted head during the accidents. The head kinematics from the video analysis was then applied to perform accidents reconstructions by use of the detailed KTH numerical head model, a helmet model and a new model of the impacted ski slope.

Results The preliminary results show that impact speeds are higher compared to the velocities used in the current test standard (5.4 m/s). It is also shown that the impact angle is very steep (Around 20° s) compared to the pure vertical impacts (90° impact angle) used in helmet standards. The simulations of the helmeted head impact do show that the rotational forces to the head is large and that the material properties of the snow is important to take into consideration when designing a new helmet standard.

Conclusion ▸ The test speed should be increased from 5.4 m/s.

▸ The rotational accelerations in the simulations are high.

▸ The ongoing project aim to answer if the specification of ski helmets needs to take the rotation into account.