Walking efficiently takes time for humans, but stability comes quickly

Walking efficiently takes time for humans, but stability comes quicklyUnlike many animals, humans don't start walking immediately after they're born; in fact, it can take children up to 18 months before they start walking.This could be because being bipedal, or walking on two legs instead of four, requires more balance when you only have two points of contact with the ground.Once we've finally learned to walk normally, we perfect it so that it costs us as little energy as possible to be stable.But there are still other challenges for us to master when it comes to moving.Walking on uneven surfaces such as cobblestones or attempting to walk on a rocking boat require us to learn new ways to manoeuvre.How long it takes us to learn these new skills is still unknown.