Skeleton involves a person riding a small sled down a frozen track while lying face down. The sport is a more intense form of luge because skeleton competitors leap onto the sled and slide downhill head first. Skeleton athletes can reach up to 80 mph on straightaways, causing forces up to 5g, so the helmet is a critical component for attitude as well as safety.

The “Hoegh Osaka” ro-ro cargo ship, operated by Hoegh Autoliners AS, sits grounded on Bramble Bank in the Solent near Cowes, on the Isle of Wight, U.K., on Monday, January 5, 2015. The car transporter was deliberately grounded after developing a list, shortly after it left the Port of Southampton. (Photo by Simon Dawson/Bloomberg)

Cocoa pods are seen on the ground at a farm in Ile-Oluji village in Ondo state, southwest Nigeria March 29, 2016. (Photo by Akintunde Akinleye/Reuters)

A doll lies on the ground near the site of a collapsed mosque, following an earthquake in Hatay, Turkey on February 7, 2023. (Photo by Guglielmo Mangiapane/Reuters)

Myanmar T-72 battle tank competes in an individual race of the Tank Biathlon competition as part of the 7th International Army Games 2021 at the Alabino training ground, Moscow region, Russia, 27 August 2021. The 7th International Military-Technical Forum “Army-2021” is held from 22 August till 04 September 2021 at 23 military training grounds of 11 countries. Five thousand participants of 277 teams from 42 countries compete in 34 military contests. (Photo by Sergei Ilnitsky/EPA/EFE)

A hot air balloon flies close to the ground in the Jezreel Valley in northern Israel during an international hot air balloon festival October 14, 2014. (Photo by Nir Elias/Reuters)

A drunk racegoer lays on the ground as her friend tries to wake her up during the Emirates Melbourne Cup Day held at Flemington Racecourse in Melbourne Australia, on November 4, 2014. (Photo by Asanka Brendon/Rex Features)