Developmental coordination disorder
Developmental coordination disorder is diagnosed when children do not develop normal motor coordination (coordination of movements involving the voluntary muscles).
Developmental coordination disorder has been known by many other names, some of which are still used today. It has been called clumsy child syndrome, clumsiness, developmental disorder of motor function, and congenital maladroitness. Developmental coordination disorder is usually first recognized when a child fails to reach such normal developmental milestones as walking or beginning to dress him- or herself.
Children with developmental coordination disorder often have difficulty performing tasks that involve both large and small muscles, including forming letters when they write, throwing or catching balls, and buttoning buttons. Children who have developmental coordination disorder have often developed normally in all other ways. The disorder can, however, lead to social or academic problems for children. Because of their underdeveloped coordination, they may choose not to participate in activities on the playground. This avoidance can lead to conflicts with or rejection by their peers. Also, children who have problems forming letters when they write by hand, or drawing pictures, may become discouraged and give up academic or artistic pursuits even though they have normal intelligence.
Causes and symptoms
The symptoms of developmental coordination disorder vary greatly from child to child. The general characteristic is that the child has abnormal development of one or more types of motor skills when the child's age and intelligence quotient (IQ) are taken into account. In some children these coordination deficiencies manifest as an inability to tie shoes or catch a ball, while in other children they appear as an inability to draw objects or properly form printed letters.
Some investigators believe that there are different subtypes of developmental coordination disorder. While there is disagreement over how to define these different subtypes, they can provide a useful framework for the categorization of symptoms. There are six general groups of symptoms. These include:
- general unsteadiness and slight shaking
- an at-rest muscle tone that is below normal
- muscle tone that is consistently above normal
- inability to move smoothly because of problems putting together the subunits of the whole movement
- inability to produce written symbols
- visual perception problems related to development of the eye muscles
Children can have one or more of these types of motor difficulties.
Developmental coordination disorder usually becomes apparent when children fail to meet normal developmental milestones. Some children with developmental coordination disorder do not learn large motor skills such as walking, running, and climbing until a much later point in time than their peers. Others have problems with such small muscle skills as learning to fasten buttons, close or open zippers, or tie shoes. Some children have problems learning how to handle silverware properly. In others, the disorder does not appear until they are expected to learn how to write in school. Some children just look clumsy and often walk into objects or drop things.
There are no known causes of developmental coordination disorder. There are, however, various theories about its possible causes. Some theories attribute the disorder to biological causes. Some of the possible biological causes include such prenatal complications as fetal malnutrition. Low birth weight or prematurity are thought to be possible causes, but there is no hard evidence supporting these claims.
It is estimated that as many as 6% of children between the ages of five and 11 have developmental coordination disorder. Males and females are thought to be equally likely to have this disorder, although males may be more likely to be diagnosed. Developmental coordination disorder and speech-language disorders seem to be closely linked, although it is not clear why this is the case. Children with one disorder are more likely to have the other also.
The diagnosis of developmental coordination disorder is most commonly made when a child's parents or teachers notice that he or she is lagging behind peers in learning motor skills, is having learning problems in school, or is suffering frequent injuries from falls and other accidents resulting from clumsiness. In most cases, the child's pediatrician will perform a physical examination in order to rule out problems with eyesight or hearing that interfere with muscular coordination, and to rule out disorders of the nervous system. In addition to a medical examination, a learning specialist or child psychiatrist may be consulted to rule out other types of learning disabilities.
The types of motor impairment that lead to a diagnosis of developmental coordination disorder are somewhat vague, as the disorder has different symptoms in different children. There are many ways in which this kind of motor coordination problem can manifest itself, all of which may serve as criteria for a diagnosis of developmental coordination disorder. The core of the diagnosis rests on the child's being abnormally clumsy. To make this determination, the child's motor coordination must be compared to that of other children of a similar age and intelligence level.
The difference between a child who has developmental coordination disorder and one who is simply clumsy and awkward can be hard to determine. For a child to be diagnosed with developmental coordination disorder there must be significant negative consequences for the child's clumsiness. The negative effects may be seen in the child's performance in school, activities at play, or other activities that are necessary on a day-to-day basis. Also, for developmental coordination disorder to be diagnosed, the child's problems with motor coordination cannot result from such general medical conditions as muscular dystrophy, and cannot result directly from mental retardation . Some criteria require that the child have an IQ of at least 70 to be diagnosed with developmental coordination disorder.
No treatments are known to work for all cases of developmental coordination disorder. Experts recommend that a specialized course of treatment, possibly involving work with an occupational therapist, be drawn up to address the needs of each child. Many children can be effectively helped in special education settings to work more intensively on such academic problems as letter formation. For other children, physical education classes designed to improve general motor coordination, with emphasis on skills the child can use in playing with peers, can be very successful. Any kind of physical training that allows the child to safely practice motor skills and motor control may be helpful.
It is important for children who have developmental coordination disorder to receive individualized therapy, because for many children the secondary problems that result from extreme clumsiness can be very distressing. Children who have developmental coordination disorder often have problems playing with their peers because of an inability to perform the physical movements involved in many games and sports. Unpopularity with peers or exclusion from their activities can lead to low self-esteem and poor self-image. Children may go to great lengths to avoid physical education classes and similar situations in which their motor coordination deficiencies might be noticeable. Treatments that focus on skills that are useful on the playground or in the gymnasium can help to alleviate or prevent these problems.
Children with developmental coordination disorder also frequently have problems writing letters and doing sums, or performing other motor activities required in the classroom— including coloring pictures, tracing designs, or making figures from modeling clay. These children may become frustrated by their inability to master tasks that their classmates find easy, and therefore may stop trying or become disruptive. Individualized programs designed to help children master writing or skills related to arts and crafts may help them regain confidence and interest in classroom activities.
For many people, developmental coordination disorder lasts into adulthood. Through specialized attention and teaching techniques it is possible over time for many children to develop the motor skills that they lack. Some children, however, never fully develop the skills they need. Although many children improve their motor skills significantly, in most cases their motor skills will never match those of their peers at any given age.
There is no known way to prevent developmental coordination disorder, although a healthy diet throughout pregnancy and regular prenatal care may help, as they help to prevent many childhood problems.
See also Disorder of written expression
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Smyth, Mary M., Heather I. Anderson, A. Church. "Visual Information and the Control of Reaching in Children: A Comparison Between Children With and Without Developmental Coordination Disorder." Journal of Motor Behavior 33 (September 2001): 306.
American Academy of Pediatrics. 141 Northwest Point Boulevard, Elk Grove Village, IL 60007-1098. (847) 434-4000. <www.aap.org> .
Tish Davidson, A.M.
Developmental disorders see Pervasive developmental disorders