Motor Skill - Human Motor Development

Motor skill is when babies start to learn how to control movement of part of the body. This process involves the coordination of muscles.

Development</span>

Due to the immaturity of the human nervous system at the time of birth, children grow continually throughout their childhood years. Many factors contribute to the ability and the rate that children develop their motor skills. Uncontrollable factors include: genetic or inherited traits and children with learning disorders. A child born to short and overweight parents is much less likely to be an athlete than a child born to two athletically built parents. Controllable factors include: the environment/society and culture they are born to. A child born in the city is much less likely to have the same opportunities to explore, hike, or trek the outdoors than one born in the rural area. For a child to successfully develop motor skills, he or she must receive many opportunities to physically explore the surroundings.

Infantile: Early movements made by very young infants are largely reflexive. An infant is exposed to a variety of perceptual experiences through the senses. For example, very young infants have a reflexive response called "rooting". By slightly stroking the side of the infants face, the infant turns its head to that side,frequently resulting in the location of food. Gradually, the infant learns that certain involuntary, reflexive movements can result in pleasurable sensory experiences, and will attempt to repeat the motions voluntarily in order to experience the pleasurable sensation.

Milestone Developmental Stages;

• 6 months â€" can sit straight
• 12 months â€" takes first steps
• 24 months â€" can jump
• 36 months â€" can cut with scissors; runs on toes

Influences on development

Stress and arousal: stress and anxiety is the result of an imbalance between demand and the capacity of the individual. Arousal is the state of interest in the skill. The optimal performance level is moderate stress or arousal. An example of too low of arousal state is an overqualified worker performing repetitive jobs. An example of stress level too high is an anxious pianist at a recital.

Fatigue: the deterioration of performance when a stressful task is continued for a long time, similar to the muscular fatigue experienced when exercised for a rapid rate or lengthy period of time. Fatigue is caused by over-arousal. Fatigue impacts an individual in many ways: perceptual changes in which visual acuity or awareness drops, slowing of performance (reaction times or movements speed), irregularity of timing, and disorganization of performance.

Vigilance: the effect of the loss of vigilance is the same as fatigue, but is otherwise caused by the lack of arousal. Some tasks include jobs that require little work and high attention.

Stages of motor learning

Motor learning is a change, resulting from practice. It often involves improving the accuracy of movements both simple and complex as ones' environment changes.Motor learning is a relatively permanent skill as the capability to respond appropriately is acquired and retained.

The stages to motor learning are the cognitive phase, the associative phase, and the autonomous phase.

Cognitive Phase: When a learner is new to a specific task, the primary thought process starts with, “What needs to be done?” Considerable cognitive activity is required so that the learner can determine appropriate strategies to adequately reflect the desired goal. Good strategies are retained and inefficient strategies are discarded. The performance is greatly improved in a short amount of time.

Associative Phase: the learner has determined the most effective way to do the task and starts to make subtle adjustments in performance. Improvements are more gradual and movements become more consistent. This phase can last for a long time. The skills in this phase are fluent, efficient and aesthetically pleasing.

Autonomous Phase: this phase may take several months to years to reach. The phase is dubbed “autonomous” because the performer can now “automatically” complete the task without having to pay any attention to performing it. Examples include walking and talking or sight reading while doing simple arithmetic.

Law of effect

Motor skill acquisition has long been defined in the scientific community as an energy-intensive form of stimulus-response (S-R) learning that results in robust neuronal modifications. In 1898, Thorndike proposed the law of effect, which states that, the association between some action (R) and some environmental condition (S) is enhanced when the action (R) is followed by a satisfying outcome (O). For instance, if an infant motions his right hand and left leg in just the right way, he can perform a crawling motion, thereby producing the satisfying outcome of increasing his mobility. Because of the satisfying outcome, association between being on all fours and these particular arm and leg motions are enhanced. Further, a dissatisfying outcome (O) weakens the S-R association. For instance, when a toddler contracts certain muscles, resulting in a painful fall, the child will decrease the association between these muscle contractions and the environmental condition of standing on two feet.

Feedback

During the learning process of a motor skill, feedback is the positive or negative response that tells the learner how well the task was completed. Inherent feedback: after completing the skill, inherent feedback is the sensory information that tells the learner how well the task was completed. A basketball player will note that he or she made a mistake when the ball misses the hoop. Another example is a diver knowing that a mistake was made when the entrance into the water is painful and undesirable. Augmented feedback: in contrast to inherent feedback, augmented feedback is information that supplements or “augments” the inherent feedback. For example, when a person is driving over a speed limit and is pulled over by the police. Although the car did not do any harm, the policeman gives augmented feedback to the driver in order for him to drive more safely. Another example is a private tutor for a new student of a field of study. Augmented feedback decreases the amount of time to master the motor skill and increases the performance level of the prospect. Transfer of motor skills: the gain or loss in the capability for performance in one task as a result of practice and experience on some other task. An example would be the comparison of initial skill of a tennis player and non-tennis player when playing table tennis for the first time. An example of a negative transfer is if it takes longer for a typist to adjust to a randomly assigned letters of the keyboard compared to a new typist. Retention: the performance level of a particular skill after a period of no use.

Types of tasks

Continuous tasks: activities like swimming, bicycling, running; the performance level is just as proficient as before even after years of no use.

Discrete tasks: an instrument, video game, or a sport; the performance level drops significantly but will be better than a new learner. The relationship between the two tasks is that continuous tasks usually use gross motor skills and discrete tasks use finer motor skills.

Gross

Gross motor skill requires the use of large muscle groups to perform tasks like walking, balancing, crawling. The skill required is not extensive and therefore are usually associated with continuous tasks. Much of the development of these skills occurs during early childhood. The performance level of gross motor skill remains unchanged after periods of non-use.

Fine

Fine motor skill requires the use of smaller muscle groups to perform tasks that are precise in nature. Activities like playing the piano and playing video games are examples of using fine motor skills. Generally, there is a retention loss of fine motor skills over a period of non-use. Discrete tasks usually require more fine motor skill than gross motor skills. Fine motor skills can become impaired. Some reasons for impairment could be injury, illness, stroke, congenital deformities, cerebral palsy, and developmental disabilities. Problems with the brain, spinal cord, peripheral nerves, muscles, or joints can also have an effect on fine motor skills, and decrease control

Cephalocaudal

This is the development from head to foot.The head develops earlier than the hand. similarly hand coordination develops before the coordination of the legs and feet. For example, an infant is able to follow something with their eyes before they can touch or grab it.

Proximodistal

Movement of limbs that are closer to the body develop before the parts that are further away, such as a baby learns to control the upper arm before the hands or fingers. Fine movements of the fingers are the last to develop in the body.

Gross to specific

Gross-to-specific pattern is the development of larger muscle movements, before the development of finer movements. For example,a child only being able to pick up large objects, to then picking up an object that is small between the thumb and fingers.The earlier movements involve larger groups of muscles, but as they grow movements become possible and specific things are achieved hence the name gross to specific.

Brain structures

The regions of the frontal lobe responsible for motor skill include the primary motor cortex, the supplemental motor area and the premotor cortex. The primary motor cortex is located on the precentral gyrus and is often visualized as the motor homunculus. By stimulating certain areas of the motor strip and observing where it had an effect, Penfield and Rassmussen were able to map out the motor homunculus. Areas on the body that have complex movements, such as the hands, have a bigger representation on the motor homunculus.

The supplemental motor area, which is just anterior to the primary motor cortex, is involved with postural stability and adjustment as well as coordinating sequences of movement. The premotor cortex, which is just below the supplemental motor area, integrates sensory information from the posterior parietal cortex and is involved with sensory guided planning of movement and begins the programming of movement.

The basal ganglia are an area in the brain where gender differences in brain physiology is evident. The basal ganglia are a group of nuclei in the brain that are responsible for a variety of functions, some of which include movement. The globus pallidus and putamen are two nuclei of the basal ganglia which are both involved in motor skills. The globus pallidus is involved with voluntary motor movement, while the putamen is involved with motor learning. Even after controlling for the naturally larger volume of the male brain, it was found that males have a larger volume of both the globus pallidus and putamen.

The cerebellum is an additional area of the brain important for motor skills. The cerebellum controls fine motor skills as well as balance and coordination. Although women tend to have better fine motor skills, the cerebellum has a larger volume in males than in females, even after correcting for the fact that males naturally have a larger brain volume.

Hormones are an additional factor that contributes to gender differences in motor skill. For instance, women perform better on manual dexterity tasks during times of high estradiol and progesterone levels, as opposed to when these hormones are low such as during menstruation.

An evolutionary perspective is sometimes drawn upon to explain how gender differences in motor skills may have developed, although this approach is controversial. For instance, it has been suggested that men were the hunters and provided food for the family, while women stayed at home taking care of the children and doing domestic work. Some theories of human development suggest that men's tasks involved gross motor skill such as chasing after prey, throwing spears and fighting. Women on the other hand used their fine motor skills the most in order to handle domestic tools and accomplish other tasks that required fine motor control.

See also

• Motor control
• Motor system
• Sensorimotor stage

References

Sparrow, W.A. (July 1, 1983). "The efficiency of skilled performance". Journal of Motor Behavior. 15 (3): 237â€"261. doi:10.1080/00222895.1983.10735299. PMID 15151872. 

External links

• Section about motor learning and control in the Wikibook "Stuttering"
• What's the difference between fine motor and gross motor skills?