Muscles don’t just move the body, they tell the brain where the body is. This sense of knowing where your arm or foot is without looking at it or touching it is called proprioception. Muscles have numerous small spring-like sensors that convey their length and tension to the brain, from this the brain creates a map of where the body is in space and uses this map as a reference to decide which muscles to activate to perform a movement.
What does this mean? If a child’s proprioception signals are inaccurate their control of movement is likely to be less coordinated.
This is why part of the assessment is to look for any restrictions in the motion of the joints and tension or weakness of the muscles along with tests for gross (whole-body) coordination and fine-motor control such as small refined finger movements and handwriting.