New parents are eager to see their children move through typical stages of development. This includes lifting their heads, rolling over, sitting, crawling, walking, and grasping or manipulating objects. These are all activities that lead to walking, independent play, and self-care. These movement patterns are called motor skills. Development of these goal-oriented motor skills requires the complex interactions of the skeletal muscles, joints, and nervous system.

There are two types of motor skills:

• Gross motor skills use the larger muscles of the skeleton or groups of larger muscles to maintain posture and balance and for activities such as throwing a ball, walking, running, and hopping.
• Fine motor skills use the smaller muscles of the hand, feet, and face for more precise activities such as eating, speaking, playing with toys, and eventually writing.

Factors that Influence Motor Development

The development and quality of a child’s motor skills are influenced by many factors. This includes tone, strength, endurance, motor planning, and sensory integration.

• Tone refers to the ongoing contraction and state of the muscle at rest. Tone can be normal, hypotonic or hypertonic . When tone is low or high, the child may have trouble moving her arms or legs because of stiffness or trouble staying balanced because of floppy muscles. These are challenges for children such as those diagnosed with cerebral palsy.
• Strength refers to the force of a muscle contraction purposefully exerted against resistance to carry out an activity. For example, a child with weak leg muscles might have trouble standing or stepping up or down stairs.
• Endurance is the ability to maintain the exertion required for an activity. A child with poor endurance might be able to step up a stair, but not climb a flight of stairs. Endurance involves many factors such as muscle tone and strength, heart and lung function, and motivation.
• Balance is the delicate interaction of equilibrium(or vestibular) centers in the brain with sensory input. Sensory input includes vision, body-position awareness, and muscle strength and tone. These factors all work together to allow your child to maintain an upright posture and to move between positions needed for activities such as sitting, crawling, walking, and reaching.
• Motor planning is the complex, and often intuitive, ability to know how to carry out the steps needed to complete a physical activity. Motor planning requires the coordination of the systems that regulate perception, sequencing, speed, and intensity of movements.
• Sensory integration is the ability to accurately interpret sensory input from the environment and to produce an appropriate motor response. Some children may have a different threshold for responding to sensory input. They may exhibit a reduced (under stimulation) or heightened (over stimulation) response to sensory information.

Links & Resources »

References:
Miller, L. J. and Fuller, D. A (2007) Sensational kids: Hope And Help for Children With Sensory Processing Disorder. New York: Penguin Group.

Tecklin, J. S. (2007) Pediatric Physical Therapy. Philadelphia, PA: Lippincott Williams & Wilkins.

www.emedicine.com/ped/topic2640.htm
Wilms Floet, A.M. (2006) “Motor Skills Disorder.” Emedicine: Medscape’s Continually Updated Clinical Reference.