Fine motor skill
Fine Motor Skills are the coordination of small muscle movements—usually involving the synchronization of hands and fingers—with the eyes. The term dexterity is commonly used to define the relationship between the fingers and eyes. The term manual dexterity is commonly used in the discourse on the theory of “Human Aptitude”. The complex levels of manual dexterity that humans exhibit can be attributed to, and demonstrated in tasks controlled by, the nervous system. Fine motor skills aid in the growth of intelligence and develop continuously throughout the stages of human growth.
Two types of motor skills
Motor Skills are movements and actions of the muscles. Typically, they are categorized into two groups: Gross Motor Skills and Fine Motor Skills.Gross Motor Skills are involved in movements of the arms, legs, or large body parts and movements. They participate in actions such as: running, crawling, swimming, etc. However, Fine Motor Skills are involved in smaller movements that occur in the wrists, hands, fingers, and the feet and toes. They participate in smaller actions such as: picking up objects between the thumb and finger, writing carefully, and even blinking. Together, these two motor skills work together to provide coordination. It’s a process that works throughout a lifetime through practice.
Fine Motor Skills develop throughout a lifetime. However, they’re first seen during a child’s development stage of: infancy, toddlerhood, preschool and school age. It’s considered “basic” fine motor skills and they will gradually develop between the ages of 6-12 in children, where children will typically master the basic fine mother skills. The motor skills at this age are characterized by involuntary reflexes. The most notable involuntary reflex is the Darwinian Reflex, which is a grasping reflex displayed in newly born babies. But, these involuntary muscle movements are temporary and often disappear within two months. After eight weeks the infant will being to voluntarily use their fingers to touch. But, their ability to grab objects is still undeveloped at that point. At two or five months the infant will being to develop hand-eye coordination. It enables improvement in grasping skills and they will start exerting some of their energy to grasping to the objects. A child will start randomly try to grab tangible and intangible objects indiscriminately. It’s soon after that infants will start to explore the dimensionality of objects prior to grabbing them. Afterwards, the next developmental milestone is between seven to twelve months, there’s a series of fine motor skills that being to develop. It includes an increase in grip, enhancement of vision, pointing with the index finger, as well as using the pincer grip to pick up tiny objects strictly with the thumb and index fingers.
It’s extremely important to be current and up to date with a child’s Fine Motor Skills during their milestones at each interval because these skills are important components for interacting and understanding, which will enable a child to under their surroundings better. Occupational Therapy can help improve your infants over all fine motor skills.
The Fine Motor Skill in toddlerhood begins with manipulation of objects with hands. Typically, toddlers will use their fingers to: twist dials, pull strings, push levers, turn book pages, and use crayons to produce crude scribbles  It enhances the motor skills because through the usage of manipulating objects on purpose, will allow identifying objects based on their shape and enable recognition of change in objects in terms of dimension. It's during this development stage of the Fine Motor Skills, a toddler will show dominance of the preferred hand, being either right or left.
A child will begin preschool usually between the ages 3 and 4 years old. Hence, by then a preschooler is capable of grasping objects using the static tripod grasp, which uses the index, thumb, and middle finger. A preschooler's motor skills are developed enough to allow them to cut shapes out of paper, button their clothes, pick up and return objects like toys. A preferred "Hand" is dominating majority of their activities.
However, children still lacking certain amount of these motor skills such as: drawing or using building blocks by this age are in danger of failing in school later on. 
These are the ages between 5 and 7, during this time children start to show dominance or preference towards a specific hand. The more dominant hand starts to develop at a much quicker pace than the submissive one, or the one that is not used as much. The movement of the elbows and shoulders should be less apparent as well as the movement with of wrist and the fingers. Children should be able to make precise cuts with scissors, like for example cutting out squares, and hold them in a more common and mature manner. The child's movement should become fluid, and the arms and hand should become more in sync with each other. Also along with this the child should be able to write more precisely on lines and print letters and numbers much more clearly. 
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. If an infant or child up to age five is not developing their fine motor skills, they will show signs of difficulty controlling coordinated body movements with the hands, fingers, and face. In young children, the delay in the ability to sit up or learn to walk can be an early sign that there will be issues with fine motor skills. Children may also show signs of difficulty with tasks such as cutting with scissors, drawing lines, folding clothes, holding a pencil and writing, and zipping a zipper. These are tasks that involve fine motor skills, and if a child has difficulty with these they might have poor hand eye coordination and could need therapy to improve their skills.
Many tests have been developed in order to assess fine motor skills. Among them include force matching tasks. Humans exhibit a high degree of accuracy in force matching tasks where an individual is instructed to match a reference force applied to a finger with the same or different finger. Humans also exhibit a high degree of accuracy during grip force matching tasks. These aspects of manual dexterity are apparent in the ability for humans to effectively use tools.
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