Because parkour philosophy is about learning to control oneself in interaction with the environment, . Daniel Ilabaca, co-founder of the World Parkour and Freerunning Federation, said "Thinking you're going to fail at something gives you a higher risk of doing just that. Committing to something you're thinking or knowing you will land gives you a higher chance of landing or completing the task." On biomechanical grounds, studies found parkour landing techniques result in lower landing forces in comparison with traditional sport techniques. In a survey of parkour-related emergency department visits in the United States between 2009 and 2015, most injuries were reportedly caused by landing or from striking objects.