Fine motor skill
Fine motor skill (or dexterity) is the coordination of small muscles, in movements—usually involving the synchronization of hands and fingers—with the eyes. 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 development.
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. 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. Gross motor skills are involved in movement and coordination of the arms, legs, and other large body parts and movements. They participate in actions such as running, crawling, swimming, etc. These two motor skills work together to provide coordination. The index is usually the most dexterous and sensitive finger of the hand.
Through each developmental stage of a child’s life and throughout our lifetime motor skills gradually develop. They are first seen during a child’s development stages: infancy, toddlerhood, preschool and school age. "Basic” fine motor skills gradually develop and are typically mastered between the ages of 6-12 in children. These skills will keep developing with age, practice and the increased use of muscles while playing sports, playing an instrument, using the computer, and writing. If deemed necessary, occupational therapy can help improve overall fine motor skills.
The first motor skills, beginning from birth, are initially characterized by involuntary reflexes. The most notable involuntary reflex is the Darwinian reflex, a primitive reflex displayed in various newborn primates species. These involuntary muscle movements are temporary and often disappear after the first two months. After eight weeks, the infant will begin to voluntarily use their fingers to touch. However, their ability to grab objects is still undeveloped at this point.
At two to five months the infant will begin to develop hand-eye coordination, and they will start reaching for and grasping objects. In this way, they improve their overall grasping skills.
In 1952, Pigaet found that even before infants are able to reach for and successfully grasp objects they see, they demonstrate competent hand-mouth coordination. A study was done by Philippe Rochat at Emory University in 1992, to test the relation between progress in the control of posture and the developmental transition from two handed to one handed engagement in reaching.It was found that the object reached for needed to be controlled. The precision of the reach is potentially maximized when placed centrally. It was also found that the posture needed to be controlled because infants that were not able to sit on their own used bimanual reaches in all postural positions except sitting upright, where they would reach one-handed. When "nonsitting" infants reached bimanually, while seated upright, they often ended up falling forward which prevented them from reaching toward the target. Regardless of their ability or lack of ability to control self-sitting, infants are able to adjust their two handed engagement in relation to the arrangement of the objects being reached for. Analysis of hand-to-hand distance during reaching indicates that in the prone and supine posture, non-sitting infants moved their hands simultaneously towards the midline of their bodies as they reached which is not observed by stable sitting infants in any position. Non-sitter infants, although showing strong tendencies toward bimanual reaching, tend to reach with one hand only, when placed in the seated posture. Sitter infants show a majority of differentiated reaches in all posture conditions.
The next developmental milestone is between seven and twelve months, when a series of fine motor skills begins to develop. These include, but are not limited to, increase in grip, enhancement of vision, pointing with the index finger, smoothly transferring objects from one hand to the other, as well as using the pincer grip (with the thumb and index fingers) to pick up tiny objects with precision.
By the time a child is one year old, their fine motor skills have developed to allow the manipulation of objects with greater intent.
As children manipulate objects with purpose, they gain experience identifying objects based on their shape, size, and weight. By engaging in hands-on play the child learns that some objects are heavy, requiring more force to move them; that some are small, easily slipping through the fingers; and that other objects come apart and can possibly be put back together again. This type of play is essential for the development of not only the child's fine motor skills, but also for learning how the world works.
It is during this stage in the development of fine motor skills that a toddler will show hand dominance.
Children typically attend preschool between the ages of 2 and 5. At this time, the child is capable of grasping objects using the static tripod grasp, which is the combined use of the index, thumb, and middle finger. A preschooler's motor skills are moderate, allowing the child to cut shapes out of paper, draw or trace over vertical lines with crayons, button their clothes, and pick up objects. A preferred hand dominates the majority of their activities. They also develop sensory awareness and interpret their environment by using their senses and coordinate movements based on that.
The National Center of Teaching and Learning illustrates the abilities that preschoolers should have improved through their fine motor skills in several domains. Children use their motor skills by sorting and manipulating geometric shapes, making patterns, and using measurement tools to build their math skills. By using writing tools and reading books, they build their language and literacy. Arts and crafts activities like cutting and gluing paper, finger painting, and dressing up develops their creativity. Parents can support this development by intervening when the child does not perform the fine motor activity correctly, making use of several senses in a learning activity, and offer activities that the child will be successful with.
Developmental disabilities may render a child incapable of performing certain motor activities, such as drawing or building blocks. Fine motor skills acquired during this stage aids in the later advancement and understanding of subjects such as science and reading. A study by the American Journal of Occupational Therapy, which included twenty-six preschoolers who had received occupational therapy on a weekly basis, showed overall advancements in the preschoolers' fine motor skill area. The results showed a link between in-hand manipulation, eye-hand coordination, and grasping strength with the child's motor skills, self-care and social function. In addition, these children were shown to have better mobility and self-sustainment.
During the ages between 5 and 7 the fine motor skills will have developed to a much higher degree, and are now being refined. As the child interacts with objects the movements of the elbows and shoulders should be less apparent, as should the movements of wrist and fingers.
Children should be able to make precise cuts with scissors. For example, cutting out squares and holding them in a more common and mature manner. The child's movements should become fluid as the arms and hands become more in sync with each other. The child should also be able to write more precisely on lines, and print letters and numbers with greater clarity.
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.
Fine motor skills can be assessed with standardized and non-standardized tests in children and adults. Fine-motor assessments can 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 of humans to effectively use tools, and perform challenging manipulation tasks such as handling unstable objects. Other assessments include but are not limited to PDMS "The Peabody Developmental Scales". PDMS is an evaluation done for children from birth till the age seven that examines the child's ability to grasp a variety of objects, the development of eye-hand coordination, and the child's overall finger dexterity. Similar to PDMS, Visual-motor integration assessment, VMI-R, is an assessment that examines the visual motor integration system which demonstrates and points out possible learning disabilities that are often related to delays in visual perception and fine-motor skills such as poor hand-eye coordination. Because additionally advancements in mathematics and language skills are directly corollated to the development of the fine motor system, it is essential that children acquire the fine motor skills that are needed to interact with the environment at an early stage. Examples of tests include:
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