Infants develop movement by progressively learning a series of fundamental movement patterns, which form the building blocks for more complex movements.
For example, while lying on the ground and sitting in various positions, an infant learns to stabilize her head so she can see the world. Her head stabilization skills are a building block for the postural control required in standing and walking. While reachingto grab interesting objects, she learns the arm/trunk coordination patterns that are also used to crawl and walk, and eventually throw and climb. As sherollsfrom back to front, she stabilizes over one leg while the other moves through space, a skill that forms the basis for locomotion.
In crawling, she uses a cross lateral pattern of limb movement that carries over to walking. And in squattingshe learns patterns of triple extension and flexion that are fundamental to almost any powerful movement in standing. By the way, some of these patterns are more fundamental than others. Although some children learn to walk without ever having crawled, none of them will learn either without the ability to stabilize the head.
These fundamental movement patterns learned in infancy can be thought of as neural control programs that can be combined in various ways to generate a large repertoire of movements.
In this sense, movement is like a language. The basic motor patterns are like letters or simple words that can be combined to form more complex sentences. In spoken language, we can communicate an infinite variety of thoughts from relatively few words.
Similarly, the complex and varied movements we see in sport and dance can all be broken down into far fewer basic movement patterns – gait, squats, reaches, rotations, etc.
An arabesque in dance looks pretty similar to the backswing of a free kick in rugby because they are built from the same basic motor primitives.
One implication of this system is that when a foundational building block is missing or compromised, the entire structure built on top will suffer. If you are missing some very basic words or letters in your language vocabulary, there are many sentences that you will struggle to make. Similarly, if your movement vocabulary is missing one or more important motor primitives, like a squat, there are very wide range of everyday movements that will be compromised. Conversely, if you improve your squat, you will improve many other aspects of your physical life.