Praxis is comprised of three components:
1) ideation-the ability to conceptualize a new or different activity
2) motor planning-the ability of the brain to organize and sequence novel motor actions
3) execution-the ability to perform motor actions
When children have dyspraxia, or difficulties with praxis, there is often a deficit in the motor planning component. Underlying that deficit is frequently poor processing of tactile, proprioceptive and/or vestibular sensory input. These three sensory systems are foundational for the development of a body percept. A. Jean Ayres discusses how forming neural memories to create a body percept is essential for motor planning in her book Sensory Integration and the Child, 25th Anniversary Edition. As children move and interact with their environment, their bodies store sensory information about their body parts—size, weight, boundaries, movements, and positions in relation to the rest of the body. The brain also stores information about the environment, such as gravity, texture, density, temperature, tensility, etc. Using the sensory information gleaned about his/her own body and incorporating the sensory information about his/her environment, the child is then able to know how fast and hard each muscle in his/her body needs to work in order to perform various tasks, how to properly use a tool, and if he/she will fall when performing a specific movement. Children with dyspraxia are often considered clumsy or awkward, and frequently have physical accidents because they lack an adequate body percept.
For most people, motor planning requires no conscious effort, they just do it. Their brains are able to do the work (motor plan) spontaneously. They might need to practice initially when learning something new, but the brain adapts; motor planning is no longer needed (remember, motor planning involves novel actions), and the action becomes automatic. For children with dyspraxia, the action does not become automatic, and they have to motor plan it over and over again. Dyspraxic children work very hard, more than other children, just trying to keep up. Subsequently, children with dyspraxia are frequently frustrated and anxious.