Children are basically hard-wired to push boundaries. They have only had their bodies for a few years, and during most of that time, they are being controlled by the adults around them. Think about it children control almost nothing in their lives. When they wake up, where they go, what they eat. Everything is almost always dictated by the people around them. So naturally as they grow and develop you should expect some pushback.
They not only are not in control of their environment but they also are trying to figure out exactly what their body can do while trying to develop their motor skills. Many parents are so quick to try to protect their children from anything and everything. However in my opinion this is doing more harm than good. Children need to be able to safely push the boundaries of their bodies to gain skills and develop their motor skills. For example, my three-year-old likes to practice her balance. Anytime there is a raised surface she will stop and attempt to walk on it. Sometimes she is able to get across without falling, other times she falls over and over, but she gets right back up and starts over until she gets it right.
As a society, I believe we have made a dangerous switch. Working at a daycare with one-year-olds, any time a child would get even slightly injured, like a scratch or a fall, we would create an incident report to give to the parents. This is fair because parents should be aware of what is happening to their children while they are away. However, due to the reaction of the parents, you had teachers following around one-year-olds doing everything they possibly could as to not let them get hurt in any way. I believe that this not only hinders a child's development but also sets them up to have lifelong anxiety.
Put yourself in their shoes. Imagine you are learning a new skill, for them, it's walking, and someone is constantly telling you to be careful. Every time they felt you were doing something wrong they would physically pick you up and stop you from practicing your new skill. This would most defiantly make it take longer for you to learn this skill. It may even make you incredibly frustrated. Now imagine someone continuously removing you from practicing your skill and then getting punished for being frustrated.
I am in no way suggesting letting your children put their bodies in danger. Children need guidance. However, they need to be allowed to participate in risky behavior safely. Children need to be allowed to get scrapes and bruises. As parents we need to trust our children to know what they developmentally need. We ned to let children test their boundaries so they know what their bodies are capable of.
I know that letting your child free range to fall and possibly get hurt is a scary thought. Our want, as parents, is to protect our children anyway that we can. We want to put our children in a bubble and keep them safe from bumps and scrapes. But this very idea is what could hinder your child from development.
Let your children explore. Let your children make mistakes and get hurt. Children are natural boundary pushers and want to know what their body is capable of. They will fall and they will get hurt. Just as anyone will have falures learning a new skill. Our job as parent is to help pick our child up and support them. Help them do hard things, and be there for them with bandais, kisses, and encouragement when they fail.