Developmental assessment involves the measure of a child's attainment of physical or cognitive skills that allow continued maturation, learning, and function in society.
Developmental assessment is used to observe functional ability in children and to identify any deviations from the norm. It is used to recognize whether or not a disability may exist and if so, where the specific problem areas lie. Developmental tests provide information regarding the milestones a child has attained, and can help in determining the course of intervention to attain further milestones. Results of developmental tests may also be used to indicate the level of progress achieved after intervention, and are often used by both clinicians and researchers.
In addition to the use of a test with established reliability and validity, a developmental assessment should include data collection in the form of an interview, history, and clinical observation. The interview should take place with the parents/caregivers and, if age-appropriate, the child, in an informal and friendly setting. The concerns and goals of the parents and child are important to note, and information regarding the child's developmental and medical history may be obtained at this time. In addition to the parent report, it is important to look at medical records if they are available. Information regarding the mother's pregnancy, labor, and delivery, and the child's medical/surgical history, health status, medications, precautions, and other items of relevance is helpful in providing a background for the assessment.
Clinical observation of the child is useful in determining factors that may contribute to developmental difficulties. In addition, it is helpful to watch a child moving under his or her own volition, instead of under a therapist's directions. Observation may include, but is not limited to: the manner in which the infant or child is held by the parent (e.g. posture, support required); preferred means of mobility (e.g. wheelchair, ambulation [walking], crawling, scooting, rolling); antigravity posture and movements; equilibrium and righting reactions; balance, including base of support; compensations; and assistance required for stability or mobility.
There are a number of assessment tools available that measure gross motor development. Some, but not all, of these tools will be summarized here.
Screening tests are the most basic form of developmental assessment tool, and are used to determine whether or not a concern exists. The Alberta Infant Motor Scale (AIMS) is used during the first year of life to identify motor delay and to evaluate maturation over time. Fifty-eight items related to posture, movement, and weight bearing in prone, supine, sitting, and standing positions take 10 to 20 minutes to observe. Researchers have found predictive validity, interrater (the consistency of the rating between different people performing the test), and test-retest reliability of the AIMS to be good. In addition, there is high concurrent validity with the Peabody Developmental Motor Scales' gross motor portion.
The Miller First Step Screening Test for Evaluating Preschoolers assesses cognitive and physical function in children 35 to 74 months of age. It uses 18 games that are age-appropriate and takes approximately 20 minutes. The Denver II is a comprehensive screening test encompassing 125 items in the personal-social, fine motor-adaptive, language, and gross motor domains. The test is norm-referenced from birth to six years; however, it has been criticized for poor specificity.
The Test of Infant Motor Performance (TIMP) consists of observation of 28 items and elicitation of 31 items in infants up to four months of age. It is found to be highly sensitive to small changes in development and valid in measuring behaviors of functional relevance. Test-retest reliability has been found to be high; more research needs to be done on predictive validity. Administration takes 25 to 45 minutes.
The Movement Assessment of Infants (MAI) is a criterion-referenced test for infants in the first year of life. Sixty-five items related to muscle strength/tone, primitive reflexes, automatic reactions, and volitional movement, including quality of movement, are assessed. Researchers report that interrater and test-retest reliability is good; however, the MAI has been found to over-identify infants with motor delay (i.e. produce a high rate of false positives).
The Peabody Developmental Motor Scales (PDMS) is a norm-and criterion-referenced test that examines gross and fine motor function in children from birth to 83 months (the second edition includes up to 71 months). The gross motor scale includes reflexes, balance, nonlocomotor, locomotor, and receipt and propulsion of objects. The
The Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) is a norm-referenced test that examines gross and fine motor function in children aged four-and-a-half to fourteen-and-a-half years. The gross motor subtests assess speed and agility, balance, bilateral coordination, and strength. The fine motor subtests assess upper-limb coordination, speed and dexterity, response speed, and visuomotor control. Administration takes 45 to 60 minutes, and reliability (interrater and test-retest) is high. Critics of the test have pointed out, however, that some of the items, e.g. "tapping feet alternately while making circles with fingers," do not measure skills relevant to everyday function. In addition, it is important to note that failure of items may result as much from cognitive and perceptual difficulties as from motor difficulties.
The Gross Motor Function Measure (GMFM) is designed to evaluate change in motor performance over time in children with cerebral palsy. The test contains 88 items in five groups: lying and rolling; sitting; crawling and kneeling; standing; and walking, running, and jumping. Interrater and test-retest reliability have been demonstrated as high.
The Bayley II consists of a norm-referenced test of motor performance (manipulation, coordination of large muscle groups, dynamic movement, postural imitation, stereognosis [the ability to recognize solid objects by touch]), and mental ability (object permanence, memory, problem solving, complex language) in children from birth to 42 months. It also contains a criterion-referenced behavior scale that looks at affect, interests, activity, and fearfulness. Test-retest and interrater reliability have been found to be higher for older ages than for younger ages with this test. This test takes approximately 45 to 60 minutes to administer.
The Early Intervention Developmental Profile (EIDP) consists of six scales in the following areas: perceptual/fine motor; cognition, language, social/emotional; self-care; and gross motor development. It is designed to be administered wholly by any member of a multidisciplinary team to children from birth to 36 months. Content validity, in addition to interrater and test-retest reliability, have been found to be good.
Assessments of functional capabilities are not necessarily developmental milestone-based; however, their use is important in determining whether or not specific disabilities exist. These disabilities may be related to mobility, transfer, self-care or social function. Examples of functional assessments include the Pediatric Evaluation of Disability Inventory (PEDI) and the Functional Independence Measure for Children (WeeFIM).
In a norm-referenced test, the child's score is compared to the average of a group of children. This average is obtained by collecting scores from a large population. In a criterion-referenced test, the scores are interpreted based on absolute criteria such as the number of items performed correctly. Raw scores on tests often can be converted to age equivalent scores, standard scores, motor quotients and percentile rankings.
Once scores are obtained, they must be analyzed along with the information gathered during the interview, history, and observation. Although the normative populations used for the tests are representative of the U.S. population, cultural differences in motor development need to be considered as well. All of this information may be used to guide intervention and/or identify areas of progress or concern. Once specific areas of dysfunction are noted, goals and objectives may be formulated to treat these areas.
Health care team roles
Physical and occupational therapists usually perform developmental motor assessments; however, the more comprehensive scales are often designed for administration by any or all members of the health care team. This team may include any or all of the following: physician, nurse, physical therapist, occupational therapist, speech and language pathologist, special educator, psychologist, and social worker. It is important that whoever administers the test takes care to learn the test and procedure for administration.
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Concurrent validity—Relationship between performance on a given test and another well-established test which is purported to measure the same skills.
Content validity—The likelihood that the test measures what it says it is to measure.
Interrater reliability—Relationship of an individual's score on first administration of a test to the score on second administration.
Predictive validity—The likelihood that a child's performance on the test predicts an actual behavior.
Specificity—Ability of a test to identify those who do not have a disorder.
Test-retest reliability—Index of agreement between two different testers for the same test.
Peggy Campbell Torpey, MPT