Children are expected to grow and develop continuously throughout their childhood.  The rate and quality of motor development can be influenced by several factors including genetic and environmental. Frequent physical exploration allows a child to understand how their body interacts with the environment. Initially, a large amount of movement produced in a newborn is caused by passive events (like being rocked by a parent) or by the child eliciting reflexes and are considered involuntary.  Each of these movements stimulates a variety of sensory receptors that provide feedback to the child including: visual, auditory, tactile, vestibular (feedback of position in relation to gravity based on receptors in the inner ear), and proprioceptive (body position and movement from receptors in the joint and muscles).  When the sensory feedback provided from an involuntary motor experience is enjoyable, the child attempts to recreate the movement.  Eventually, through repetition and practice, the child is able to reproduce the movement voluntarily or purposefully resulting in motor learning.

 

Repetition and practice are key components to motor learning. Continual rehearsal of a motor skill allows the child to produce smooth, fluid, and coordinated movement.  With enough practice, motor skills become somewhat automatic and no longer require the child's continuous attention in order to complete the task. If a child does not enjoy or is confused by the sensory feedback they receive from a given movement, they may lack the motivation to practice that motor skill.  Similarly, if a child does not enjoy the physical demand of a given task, they may also lack to motivation to practice.  This lack of motivation to practice can result in a delay in acquiring the motor skills.  For example, a child that does not enjoy the physical demand or sensory experience of being on their tummy may avoid practice of motor skills in this position delaying their acquisition or mastery of skills like: propping on hands while on their tummy, rolling, pivoting on their tummy, and even crawling.

It is important to recognize if your baby or child has an intolerance for certain positions or appears to have difficulty with a certain task and inform your clinician or pediatrician of this. This way you can ensure the appropriate intervention is initiated before there is a significant delay or poor habits are formed. 

 

 

We have three different types of muscles in our bodies: smooth muscle, cardiac muscle, and skeletal muscle.  Smooth muscle or involuntary muscle is found on the walls of most organs in our body and among other things works to regulate blood flow through vessels, move food through our GI tract, and regulate air flow in our lungs. Cardiac muscle makes up the walls of the heart, contracts an average of 70 times per minute in order to pump 5 Liters of blood per minute throughout the body.  Cardiac muscle is also considered involuntary.  Skeletal muscle is named so because it is attached to the skeleton (bone).  Skeletal muscle is contracted through voluntary control. The rest of of this article will be in reference to skeletal muscle.

 

The result of skeletal muscle contraction is one or more parts of the body moving through space.  In order for our limbs to move in smooth, coordinated patterns, the muscles must cooperate with each other.  In other words, they must rest when they are supposed to rest and contract when they are supposed contract.  During every movement there is an agonist muscle and an antagonist muscle.  The agonist, or prime mover, can contract concentrically or eccentrically to move the desired part of the body.  For example,  during a bicep curl, the bicep contracts concentrically to lift the weight up while bending the elbow and then contracts eccentrically to lower the weight down while straightening the elbow.  The antagonist muscle is the muscle performs the direct opposite movement of the agonist.  Using the same bicep curl example, the antagonist would be the tricep as it is responsible for straightening the elbow. Therefore, the tricep must relax while the bicep is contracting to lift the weight.  If there has been damage to the central nervous system it often affects the ability of muscles to contract and rest at the appropriate time, therefore making controlled movement very difficult.