INTRODUCTION

Children who come to the attention of Child Protective Services (CPS) have experienced child abuse, neglect, or abandonment, and thus become involved with the child welfare (CW) system. Among this group of children, placement may be in out-of-home care, such as traditional foster care (FC) with a nonrelative caregiver, or in kinship care (KC) with a caregiver who is a relative, although much of the published literature about children in out-of-home care combines both groups within the category of “foster care” and may not distinguish between these 2 conditions. More than 423 000 children involved with CW in the United States live in out-of-home care.1 In addition, some children involved with CW continue to reside with their own parent(s) while the family receives “in-home” Child Protective Services (IHPS) and often are not included in studies pertaining to children in out-of-home care. This article will use the term CW to include children when all 3 conditions are combined (FC, KC, and in-home), and will specify FC or KC when possible.

Children involved with CW tend to have more developmental and health problems than age-matched peers, but the etiology of these problems is not well known. Depending on the study, between 35% and 92% of children involved with CW have medical problems2–5 and up to 61% have developmental delays,5–8 which have been documented in a variety of domains,3,4,8–12 including motor skills.4,8,11,12 The American Academy of Pediatrics acknowledges that the youngest children are at particularly high risk for developmental delay9,10 with 33% to 37% of children involved with CW younger than 5 years identified with developmental delays13 and up to 45% of those in FC found to be eligible for early intervention (EI) services under the Individuals with Disabilities Education Act.11 In comparison, estimates of developmental delay among children younger than 5 years in the general population are 10% to 16%.14

Few studies have examined motor development in young children involved with CW. Current estimates are that 24% to 49% of young children involved with CW have motor delay,4,8,11,12 compared with 16% in the general population,14 however, limited attention has been directed to this discrepancy. Whereas each of these 4 studies used different motor scales to assess motor delay, they all simply reported its incidence (2 report gross motor [GM],4,8 1 fine motor,8 and 2 report motor composites without distinguishing between fine or GM11,12). Of the 4 studies that report motor delay among children involved with CW, none examined factors correlated with motor deficits or explored why delay occurred at a higher rate. An understanding of such factors can help lead to early identification of motor deficits, which is important for young children to encourage prompt diagnostic work-ups and proper intervention and treatment.15 It can also provide timely support to families and may lead to prevention of academic and psychosocial problems associated with motor deficits.15–17

Delayed motor development among children involved with CW is a topic that warrants further investigation. This issue is more compelling because many children involved with CW do not receive adequate or timely health care,2,4 which is the gateway for most young children with delays to access EI and physical therapy services. In addition, current standards of care for children in FC call for comprehensive health and developmental assessments upon entering care, and at regular intervals thereafter.9,10,18 However, if these children are not accessing routine health care, it is unlikely that they are obtaining either physical therapy or EI services. A better understanding of factors that affect motor development in young children involved with CW can improve our efforts to identify and refer children for appropriate interventions to enhance their developmental outcomes.19,20

Young children involved with the CW system experience a variety of adverse risk factors that may affect their motor development. Maltreatment involving physical abuse can result in bone fractures and delayed or deferred medical care, with significant sequelae if the growth plates are damaged. Head trauma from blows to the head or shaken impact syndrome may result in a range of motor deficits from poor coordination to conditions like cerebral palsy.21 Neglect is the primary reason young children enter the CW system, and it can affect motor skills secondary to excessive confinement to infant equipment or malnutrition.21

The vast majority of children involved with CW are born into families struggling with poverty, with its profound affect on health and family functioning. Factors (eg, poverty, substance abuse, and domestic violence) that predispose a woman to deliver an infant who is premature also are associated with the involvement of CPS and foster placement.22,23 Children born premature with lower gestational age have been found to have poorer motor skills than children born full-term even when their chronological age is adjusted (on the basis of their length of gestation) to correct for prematurity.24–29

Studies examining the effect of prenatal cocaine exposure (PCE) on children's development have found that infants with PCE are far more likely to be placed in FC or KC than matched controls without cocaine exposure.30–33 A number of studies indicate that PCE affects motor functioning during infancy16,34–43; however, significant methodological limitations of some of these studies30 must be considered. Prenatal cocaine exposure generally occurs within the context of polydrug use, with exposures to legal teratogens, such as tobacco and alcohol.16 The findings are inconsistent even with studies that are well-designed and control for exposures to alcohol and tobacco, as illustrated by 2 prospective longitudinal birth cohort comparison studies of the effect of PCE on motor development.16,33 Singer et al33 found that prenatal tobacco exposure predicted lower motor scores, while prenatal exposure to cocaine affected cognitive development. Miller-Loncar et al16 found that infants with PCE demonstrated lower motor skills at 1 month of age but that these early differences were not sustained over time. It is noteworthy that numerous studies indicate that smoking and significant use of alcohol during pregnancy have more serious effects than that of PCE.44,45 Prenatal alcohol exposure has been associated with young children's orthopedic and motor abnormalities, motor delays, and balance deficits.46–48

Type of placement has been shown to influence developmental outcomes. As described earlier, children with CW involvement may be placed in FC, KC, or remain with their own parents and receive IHPS. Among children involved with CW, those in out-of-home placement (FC or KC) are more likely to receive primary health care and educational services than those who remain with their parents with in-home CW intervention.49

Type of placement is also associated with the prevalence of children with special health care needs. Children placed in FC are more likely to have special health care needs than those placed in KC or those with IHPS.7 Length of time in placement and the number of placements children experience also have been shown to affect developmental and behavioral outcomes.3,8,50 For example, Horwitz et al3 found that adaptive behavior functioning significantly improved over a 12-month period of FC placement, and that time in FC placement contributed to improved functioning in a multiple regression prediction model. Alternatively, in an earlier study, Horwitz et al51 found that when children entering FC had developmental, medical, or behavioral problems, they were more likely to remain in care longer than their peers. The number of placements a child experiences (placement stability) can affect development, as an increased number of placements is associated with decreased continuity of health care,52 increased emergency department use,53 and increased mental/behavioral health problems.50,54,55

Reasons for out-of-home placement in FC or KC have been found to be associated with various medical problems,5 the likelihood of having medical problems identified,11 and improvement in scores on the composite Vineland Adaptive Behavior Scale after placement.3 In addition, researchers have shown that children placed in FC due to neglect/abandonment or abuse have lower scores on developmental testing than children in the general population5,56; however, motor delay and reason for placement have not previously been studied.

The objective of this study was to determine whether a sample of children aged 2 to 34 months and involved with an urban CW system had a higher rate of GM delay than children in the general population. We examined the relationship between GM development and other variables affecting developmental outcomes: prenatal exposure to illicit drugs,16,34–43,57 weight-for-height ratio,29,56,58–62 head circumference,60 gestational age,24,25,27–29 and factors specific to CW involvement discussed earlier that have been implicated in developmental outcomes: placement type,7,49,52,63 number of placements,52,53,55 reason for placement,3,5,11,56 and length of time of CW involvement.3,8 Finally, we evaluated the interaction among these factors and their combined influence on GM development.

METHODS

This study is based on the information gathered through a demonstration project involving an interdisciplinary pediatric evaluation and follow-up clinic for infants and toddlers with open CW cases. The evaluations aimed to identify the children's health and developmental needs provide recommendations for health care and EI services based on the evaluation results, monitor adherence to these service recommendations, and identify barriers families encountered that compromised adherence. All children involved in the clinic received an interdisciplinary evaluation: medical evaluation, including a physical examination, measurement of growth parameters (weight, length, and head circumference), and evaluation with standardized, normative measures for gross-motor, cognitive, and speech-language development. Prior to evaluation, the team social worker conducted a structured interview to gather demographic information, and social and medical history from the child's caregiver (birth parent and/or foster parent) and CW caseworker. Information from the structured interview and results of the interdisciplinary evaluation (eg, health status, growth parameters, developmental tests results, and adherence information) were maintained in a deidentified clinical database. This study was approved by the Institutional Review Board of The Children's Hospital of Philadelphia.

Sample Characteristics

Participants were recruited at the inception of the model clinic, with a letter sent to 60 agencies that were part of a consortium of private, nonprofit CW-provider agencies. The letter described the evaluation format and eligibility requirements (children between 2 and 34 months of age who had open cases with the county CW authority for FC, KC, or IHPS). The letter described the clinic as an opportunity for the child to receive a pediatric interdisciplinary developmental evaluation, with an EI service coordinator present to initiate enrollment for EI services should the child's evaluation results warrant EI services. Between 2002 and 2004, 218 children were evaluated (Table 1). Data from this convenience sample were analyzed for the present study. Of the 218 children referred, 176 were included in the current analyses. Children who did not receive testing for the GM domains of the Peabody Developmental Motor Scales, 2nd edition (PDMS-2), were excluded.

Measures

Gross Motor Ability: PDMS-2

All subjects were evaluated on the GM subscales of the PDMS-264 to yield the GM quotient (GMQ). The PDMS-2 has been shown to be a valid, reliable measure of motor skills for children from birth to 72 months.* The entire test consists of 7 subtests, 4 of which make up the GM domains: reflexes, stationary, locomotion, and object manipulation. The administration of 2 of these subtests is age-determined, with reflexes used with children younger than 12 months and object manipulation used with children 12 months and older. The GMQ is then derived from a composite of the 3 administered GM subtests. When scored, the raw scores on the PDMS-2 subtests can be converted into age-equivalents, percentiles, and subtest standard scores. Subtest standard scores are combined to yield a GMQ, which is a standard score with a mean of 100 and a standard deviation of 15.

The PDMS-2 is considered one of the gold standards for GM assessment for children from birth to 72 months. The GMQ has good to high internal consistency (0.96),64 test-retest reliability (0.84–0.99),64,65 and inter-rater reliability (0.89–97).64,66–69 The PDMS-2 GMQ has variable concurrent validity with other GM tests (0.30–0.86)64,68,70,71 and fair to good convergent validity (0.71–0.76).72 Other studies have examined various aspects of reliability and validity of subtest scores, age equivalents, and previous editions of the PDMS.71,73,74 In total, the literature supports the PDMS-2 GMQ as a reliable and valid test to assess for GM delay in children ages from birth to 12 and 24 to 60 months, but there is limited research regarding its use in the 12- to 24-month age range.64–74 It has also been suggested that the original PDMS and the PDMS-2 may not be sensitive to cultural differences in various populations, including African American, Hispanic, Native American, and Indian children.75–77

Although other measures may be stronger in some age-related subsets of our sample for GM assessment, the PDMS-2 GMQ was chosen a priori as the best measure to use across the sample to capture GM ability for 2 reasons. The clinic included only 1 measure of GM ability to limit the testing burden on the infant who was also receiving developmental assessments of communication and cognitive development on other measures. In addition, the infants were part of a follow-up program and many returned for re-evaluations at planned intervals, thus use of a consistent measure of motor development was preferable for tracking their progress. In this study, we examine data only from participants' first evaluation. The PDMS-2 GM subscales were administered by a physical therapist.

Growth Parameters

A pediatrician measured growth parameters (height, weight, and head circumference), calculated weight for height ratios, and documented percentiles on the basis of gender and gestational age.78 Head circumference and weight are associated with developmental outcomes,60 and the age of achievement of motor milestones is associated with all growth variables that include weight.58

Chronological and Gestational Ages

Chronologic age (in months) was determined on the basis of the date of the child's evaluation. Gestational age was determined from birth hospital discharge records when available, or by birth parent's report, and reported in weeks. Scores for PDMS-2 were based on corrected age for all patients less than 24-months-old when prematurity was identified.

Collateral Information

The following information was gathered from the structured interview detailed earlier: (1) Placement type: (FC, KC, in-home protective services) represents type of CW placement at the time of evaluation. (2) Time with CW: (in months) represents the length of time since the child's case was originally opened with CPS. (3) Number of placements: we divided the subjects into 2 groups depending on placement stability: stable (indicating 2 or fewer placements) versus unstable (those with 3 or more placements). (4) Prenatal exposure: was coded yes/no/unknown and represented illicit drug use, such as cocaine and opiates. We did not have access to direct perinatal assessment of the actual exposures our sample experienced; because this was a convenience sample of children 2 months and older, we relied on CW agency documents for this information. Given the limitation of using CW documents, we were unable to document prenatal tobacco and alcohol exposures within this variable despite their known effect on motor development.33,46–48,79 (5) Reason for placement: physical abuse, sexual abuse, neglect, medical neglect, abandonment, housing problems, parental substance abuse, maternal mental illness, abuse of siblings, maternal incarceration, or other (Table 2). This variable refers to the reason for the child's involvement with the CW system and included children receiving in-home services as well as those in placement. In contrast to the prenatal exposure category, when the reason for placement was due to parental substance abuse, reason for placement-parental substance abuse included any type of illicit drug or alcohol abuse. In addition, children in our sample may have entered the CW system for multiple reasons, so some children fell into multiple groups. For purposes of data analysis, we compared the means of each group with the rest of the sample. We also created a category of children referred for any type of abuse or neglect. For this category, to prevent duplication of subjects, children referred for 2 types of abuse are only represented once.

Data Analysis

Data from 218 children who received evaluations were compiled from clinic visits. One hundred seventy-six subjects received assessments on the PDMS-2 GMQ. Data were analyzed using SPSS v.17.0.80 Missing values for independent variables were excluded list wise for all analyses. Descriptive statistics were computed for all variables. Spearman's ρ correlation coefficients were estimated for continuous variables (gestational age, chronologic age at the time of evaluation, weight-for-height percentile, head circumference percentile, time with CW). The independent t test for 2-group comparison (number of placements, prenatal exposure, and reason for CW involvement) and analysis of variance and covariance (ANCOVA) for 3-group comparisons (placement type) were used. In comparing GMQ among the placement types, time in CW and head circumference were used as covariates. Stepwise multiple regression analyses were used to predict GM scores for children involved with the CW system.

RESULTS

Data from the PDMS-2 for 176 children were included in our analyses. The mean GMQ was 94.83 ± 12.72 (range: 43–119), and 13.6% (n = 24) had GMQ less than 80 (1.5 standard deviation below reported mean), indicating GM delay.* The mean age was 15.38 ± 8.39 months, and the mean time with CW was 6.95 ± 7.24 months. The percentage of children in FC was 48.8; 27.8% were in KC; and 22.7% with IHPS. Ten percent had 3 or more placements. The percentage of children reportedly exposed to substances in utero was 45.5%. The most frequent reasons for CW involvement were abuse or neglect (46.6%) and parental substance abuse (43.2%). Of the sample, 83.5% was African American, whereas 8% was white. Data are also presented for each of the CW subgroups (FC, KC, and IHPS; Tables 1 and 2).

Table 3 reports Spearman correlation coefficients. A positive correlation was found between GM score and weight-for-height percentile (r 156 = 0.218; P < .05), where children with a higher percentile had higher GM scores. There was a negative correlation between GM score and age at the time of assessment (r 176 = −0.382; P < .001), indicating that younger children had higher GM scores. Head circumference percentile was negatively correlated with time with CW (r 153 = −0.200; P < .05), while positively related to gestational age (r 153 = 0.182; P < .05), and weight-for-height percentile (r 153 = 0.243; P < .01), which indicates that children with smaller head circumferences experienced greater time involved with CW, had lower gestational age, and had lower weight-for-height percentile. Age at the time of assessment was negatively correlated with weight-for-height percentile (r 156 = −0.237; P < .01), which indicates that older children tended to have lower weight-for-height percentiles.

Tables 4 and 5 report GMQ means and t test/ANOVA and ANCOVA results. Compared with other reasons, children involved with CW due to abuse or neglect, medical neglect, and parental substance abuse had lower GMQ and those involved for abandonment had higher scores. There were significant differences between GMQ means for those who entered CW due to medical neglect (P < .01) or all types of abuse or neglect (P < .05), whereas differences for children who entered because of abandonment and parental substance abuse approached significance (P = .088 and P = .09, respectively). Comparing GMQ between placement type, using time in CW and head circumference as potential covariates, ANCOVA indicated that time in CW was a significant confounder. After adjusting for time in CW in post hoc analysis, a significant difference was seen between GMQ for KC and FC (FC, KC [F 1,131 ] = 12.55, P = .001) and the difference between GMQ for KC and IHPS becomes significant (KC, IHPS [F 1,86 ] = 5.31, P = .024), such that children in KC had higher GMQ than those in either FC or IHPS (see Table 5).

TABLE 4: t test: Comparison of Means for Number of Placements, Prenatal Exposure, and Reason for Child Welfare Involvement TABLE 5: ANOVA and ANCOVA for Comparison of Groups

Table 6 reports the multiple regression analysis on the basis of 149 cases with complete data sets. The PDMS-2 score was the dependent variable. In the model, age at the time of assessment most strongly predicts GM outcome, and medical neglect as the reason for CW involvement also contributes. When both variables are included, 19.4% of the variance in GM outcome is explained. Given this model, the variables that contribute most strongly to GM developmental outcome are age and medical neglect.

DISCUSSION

The results of this study indicate that young children involved with the CW system have a lower mean GMQ score on the PDMS-2 (GMQ = 94.83) when compared with its normative sample (GMQ = 100), suggesting that our sample's motor development is less advanced than what has been reported for children in the general population. Our concern about this finding is intensified when we consider the demographics of our sample, which comprised 83.5% African American children, with only 8% white children. However, one must also consider the possibility of measurement error in scoring, given the difference is less than half a standard deviation. With a lower mean GMQ in our sample, one would expect that a higher rate of children with motor delay would have been identified. It seems paradoxical to find that our sample's rate of motor delay (13.6%) actually corresponded to the rate identified among children in the general population,14 in contrast to the higher prevalence identified among foster children in previous studies.4,8,11,12 It should be noted that one of the earlier studies of children involved with the CW system4 also used the PDMS (1st edition) with a large sample of primarily African American children and identified GM delay among 31% of the sample.4 However, the criterion used for establishing the category of delay was based on a standard score below 85, while our criterion was more restrictive (ie, standard score below 80), which may help to explain the lower rate of GM delay among our sample.

Another possible explanation for the unexpectedly low rate of motor delay may be due to the measurement bias introduced because our sample's composition is disproportionate to the PDMS-2 standardization sample. We might speculate that if African American children generally achieve GM milestones at an earlier point relative to white children, when their development is delayed, it will not be as readily identified by measures with norms that are not representative of this group of children. Cohen et al75 have suggested that the 1st edition of the PDMS does not account for cultural differences in African American and Hispanic children, and may “lead to erroneous conclusions regarding their developmental status.”75(p195) When their study was conducted, the 1st edition's standardization sample was outdated, resulting in the under-representation of African American children.75 Considering that the proportion of African Americans in the general population had increased at the time of their study, the validity of the PDMS for African American children was brought into question.75 Two additional studies examined the relationship between culture and performance on the PDMS (with Native American children) and the PDMS-2 (with children in India), respectively.76,77 Each confirmed that children with cultural backgrounds not sufficiently represented in the measures' standardization samples may perform differently on the respective editions of the PDMS, and that these cultural groups were not adequately represented in its published norms. Although these 2 studies did not include African American children, they highlight the limitations of published test norms developed primarily with a white sample.

In summary, given the racial demographics of our sample and our more restrictive definition of motor delay, our finding of a lower mean GMQ than reported normative values warrants concern about the need to identify factors that compromise the development of GM skills among young children involved with the CW system.

The results of this study point to several factors that affect GM developmental outcome: weight-for-height percentile, age at the time of assessment, placement type, and reason for CW involvement (medical neglect, abuse or neglect, abandonment). Our finding that weight-for-height percentile is positively correlated with GM scores is consistent with previous research indicating that weight/height variables affect motor outcome.58,60 This finding may reflect the fact that children in FC are at increased risk for growth delay.81 Wyatt et al81 reported that in their sample of children who entered FC with a growth deficit, half experienced catch-up growth in the 1st year of placement. Our sample had been in care for over 6 months on average; thus, it is likely that many had already experienced at least a portion of their catch-up growth at the time of evaluation. This finding suggests that there may be other variables related to weight-for-height ratio, such as a history of deficient nutrition and limited environmental stimulation, which affect motor development beyond initial deficits in growth. For example, nutritional deficiency that contributes to poor growth may affect muscle mass, strength, and endurance and thus impede progress in achieving motor milestones. Alternatively, this finding might be an artifact of prenatal exposures to alcohol, tobacco, and/or cocaine, although the research concerning their effect on growth has been inconsistent, with some studies reporting decreased growth32,47 and others reporting that such growth delay is not sustained over time.16,40

The finding that age at the time of assessment is correlated with GM outcome warrants consideration. A child's GMQ should remain relatively constant in the absence of GM intervention.64 The finding that the older children involved with CW have lower GMQs suggests that there may be something about the length of time children are exposed to the adverse conditions that result in CW involvement that affect their motor outcome. Older children may have experienced neglect or abuse for longer periods before coming to the attention of CPS, thus, limiting their opportunities for GM skill attainment. Future studies should consider the children's age at the time of CW involvement as well as age at the time of assessment. A prospective longitudinal study of the motor development of children involved with CW could provide a better understanding of this age-related GM performance. Alternatively, the finding that age is related to PDMS-2 score may simply be an artifact of the test itself, given that the reliability and validity of the PDMS-2 for children in the 12- to 24-month age group have not yet been established by independent studies.

With both weight-for-height percentile and age correlated with GMQ, as well as correlated with each other, it may be that these 2 variables are integrally related to GM developmental outcome. As with GMQ, weight-for-height percentile should remain relatively stable over time in the absence of a known intervening factor (eg, significant weight loss or gain associated with medical conditions). When both variables were put into the multiple regression model (Table 6), only age was needed to explain the variance in GMQ. Older children may have been subject to poor conditions for longer periods negatively affecting both growth (weight-for-height percentile) and GM performance (GMQ). Further investigation into the specific tendencies of GM performance and growth over time for children involved with CW is needed.

We found that children involved in CW due to medical neglect or for any abuse or neglect had lower scores on GM scales, which is consistent with prior studies showing that children with histories of neglect/abuse have delayed development.5,56 Our results may be related to neglect of physical stimulation. For example, children who routinely experience prolonged confinement to an infant seat will not have adequate opportunities to practice and refine motor skills, impeding their developmental progress. Other facets of neglect, such as inadequate nutrition resulting in weakness and malaise, may have compromised of motor development. Children who enter the CW system due to substantiated medical neglect are highly likely to have complex and chronic medical conditions or disabilities that warrant increased medical monitoring and ongoing intervention; health care providers rarely contact CPS regarding medical neglect in situations when a child who does not have a significant health problem merely misses routine preventive health care appointments. In turn, children with complex or chronic conditions are more likely to experience developmental delays when compared with children in the general population. Children experiencing medical neglect may miss adequate or timely health care appointments, a venue in which motor delay may first be recognized by health care providers. Routine health care visits most frequently result in children's referrals to EI services through Individuals with Disabilities Education Act, and thus access to services that can mitigate the effects of early motor delay.

In contrast, we found that children referred for abandonment had higher GM scores than the rest of our sample, differing from Takayama et al5 finding that abandoned children had poorer developmental scores. Given our sample's restriction to infants and toddlers, we surmise that abandoned children in our study may have been placed with a foster or kinship family very early in life (earlier than most children in Takayama's sample), leading to a stable environment, appropriate stimulation, access to health care, and a shorter period of exposure to the adverse conditions inherent in maltreatment.

Finally, we found that children placed in KC had higher GM scores than those in FC or IHPS, even when adjusted for significant differences in time involved with CW. It has been documented that children who are medically complex are more likely to be placed in nonrelative FC7; thus, we can speculate that they may be more likely to have delayed motor skills resulting from their significant medical conditions. This would suggest that the children placed in KC were more likely to have typical health status and thus not have the risk factors associated with chronic health and neurodevelopmental conditions that are associated with motor delay. Previous research differentiating between children involved with CW who remain with their parents and those in out-of-home care (either FC or KC) is limited. It may be that children with IHPS continue to be exposed to unfavorable conditions, which, in turn, delay GM skill acquisition. These less than optimal conditions may not be such to endanger the child's physical safety (thus IHPS is the appropriate placement) but sufficient to undermine GM development. There may also be something unique to children in KC or the kinship environment that affects outcomes in these children.

Multiple regression results provide an indication of factors that most strongly affect GM developmental outcome (age and medical neglect as the reason for CW involvement). This method has not previously been used to examine factors related to motor development or to determine which factor most strongly affects motor outcome in children involved with CW. This information may begin to assist health care and CW professionals in better identifying children at risk for GM delay, and facilitate access to more timely diagnosis, interventions, and treatment.

There are several limitations to this study. We had a large sample size for a study of this kind, with racial and ethnic demographics that were proportionate to those of children younger than 3 years involved with CW served by the county CW authority, but it was a sample of convenience. A major source of data was based on historical information primarily provided by the CW agency worker and on information from the child's agency file, including official documents. Although the reliability of this information cannot be confirmed, it is the information typically available to health care providers and foster parents. This method of data acquisition was problematic because some data were missing for independent variables, which yielded 149 subjects with complete data sets. It is possible that this missing data affected the findings of this study. Another drawback was our inability to confirm prenatal exposures to legal and illegal teratogens. Because of the historical nature of many of the independent variables, the variable regarding prenatal exposures excluded prenatal exposures to tobacco and alcohol, despite their potential effect on motor development. This is regrettable because prenatal exposure to tobacco and alcohol has been shown to affect children's motor skills.33,46–48,79

The PDMS-2 may be the gold standard in the field; however, as an outcome measure for GM skills, it does present some limitations in this study. The mean age of our sample was 15.5 months, and it has been suggested that the PDMS-2 may not be as strong at evaluating motor development within this age range. Our sample also included 83.5% African American children. Given the possible cultural differences on the PDMS and PDMS-2,75–77 the PDMS-2 may not have been sufficiently sensitive to motor development for this sample. However, no other standardized motor scales with better reliability and validity are available for use across the entire sample (ages 2–34 months). Finally, we were unable to conduct reliability/validity studies for our data, including within raters, or between raters on the PDMS-2, as well as with growth measurements and historical information gathered via interviews.

To our knowledge, this is the first study to examine the factors affecting GM development among young children involved with the CW system. Further prospective research should examine children in the 3 placement groups (FC, KC, and IHPS) to determine whether differences in GM outcome are maintained over time, as well as to further examine the interplay between GM outcome with age, length of time in CW, and growth parameters in these groups. We also need to gain a better understanding of how the various factors discussed earlier affect motor development. Is there something about a lower weight-for-height ratio that predisposes a child to poor motor skills (eg, less muscle mass or strength, poor nutrition)? Is there something about children who enter CW due to abandonment that distinguishes them from other children involved with CW? Why do children experiencing medical neglect have poorer motor development? How does age interact with CW experiences to affect GM skills? Once we have a better understanding of the role of these factors, additional research can examine ways to address motor delay in this population. In addition, further study is needed to examine the limitations of the PDMS-2 in assessing children involved with CW and cultural/racial influences on performance on this measure.

CONCLUSION

Children's initiation into the CW system results from extraordinary risks to their well-being and safety. This study confirms that very young children involved with CW have heightened risk for motor deficits, with children in FC having the greatest risk, followed by children in IHPS. On the basis of the results of this study, children in KC appear to have relatively preserved GM skills. This study raises questions regarding the link between growth parameters, maltreatment history, placement type, CW experiences, and motor performance in young children. In light of the relationship between motor development and referral to CW for abuse/neglect and medical neglect, the results support the recent advances in federal policy established by the reauthorizations of the Child Abuse Prevention Treatment Act of 2003 and Individuals with Disabilities Education Act of 2004, which mandate referral for EI services (which includes physical therapy) for children with substantiated cases of maltreatment. The findings in this study provide information for pediatric physical therapists, so they can better identify, treat, and advocate for children involved in CW system.