Young girls practice acrobatic skills in the Sichuan Provincial Art School July 14, 2008 in Chengdu of Sichuan Province, China. (Photo by China Photos/Getty Images)

Young gymnasts practice pull-up on a bar at a gymnasium of a sports school in Jiaxing, Zhejiang province April 11, 2015. (Photo by William Hong/Reuters)

Young contortionists practice at a training school in Ulaanbaatar, Mongolia, July 4, 2016. (Photo by Natalie Thomas/Reuters)

Dancers at the Windmill Theatre in London, England practice a routine wearing gas masks and hard-hats with their costumes, 1940. (Photo by Hulton Archive/Getty Images)

Private Harold L. Langhofer edges into the ball-turret, March 9, 1943. Curled in this position, he can turn the turret so that it fires in any direction. The turret can also be swung around so that the hatch opens into the plane, and the gunner can crawl into it while the Flying Fortress is in motion. (Photo by AP Photo)

The scene in Star Lane, Dunmow, Essex, after a steam traction engine from Sussex on its way to the Saffron Walden Crank Up weekend steam show, crashed into a private dwelling on Friday, April 21, 2023. (Photo by Nicholas.T.Ansell/PA Images via Getty Images)

Kung Fu master Li Liangui practices “Suogugong” Kung Fu and his wife Liang Xiaoyan (R) practices Qigong at a park in Beijing, China, June 30, 2016. For 50 years, kung fu master Li Liangui has been contorting his body into eye-watering positions while practising one of the more unusual and less popular Chinese martial art forms. The 70-year-old is an expert in suogugong, or body shrinking kung fu, where practitioners dislocate their bones to help them achieve unlikely positions and feats. (Photo by Kim Kyung-Hoon/Reuters)

Vickie Leuenberger (L) practices with a mermaid tail with AquaMermaid founder Marielle Chartier Henault in a pool in Montreal, February 19, 2015. The school teaches kids and adults how to swim wearing mermaid tails, and offers mermaid-themed parties. (Photo by Christinne Muschi/Reuters)