Are teaching principles associated with improved motor performance in children with developmental coordination disorder? A pilot study.

Evidence for positive treatment effects in children with developmental coordination disorder (DCD) is becoming available as more task-oriented training programs are developed. (1,2) Children with DCD, also described as clumsy or dyspraxic, experience difficulties in acquiring adequate motor skills, such as writing or catching a ball. (3) They are traditionally treated with sensory integration, process-oriented, and perceptual motor programs. Scientific evaluation studies have shown few effects of these programs on the motor performance of children with DCD. (4) In more recently developed programs, which are very promising, therapists become skill teachers. They guide the child with DCD in the process of learning motor skills that children typically learn informally and perform without close attention. (3)

Effectiveness studies so far have disregarded the teaching skills of physical therapists, even though these might be major factors contributing to the success of managing DCD. A task-oriented treatment program that pays special attention to how therapists teach motor skills is neuromotor task training (NTT). (5) Neuromotor task training is a child-centered treatment program suitable for children with DCD. It is based on recent scientific information on variables that affect motor control and motor learning. (6,7) This information is incorporated into NTT to enhance motor learning in general and to enhance transfer to activities of daily life in particular. However, it is unclear whether the knowledge gathered through research in artificial laboratory experiments, often with healthy children or adults, applies to motor teaching in therapeutic situations. (6,8,9) This study is a first attempt to empirically associate therapeutic success with the teaching principles used by physical therapists who provide NTT to children with DCD.

Neuromotor task training is a tailor-made program developed in the Netherlands for children with DCD. (5) A physical therapist treating according to NTT teaches the motor tasks with which a child experiences problems. The choice of tasks depends on the individual needs of the child as well as on the expectations, capabilities, and motivation of the child and the parents. Physical therapists start by assessing the strengths and weaknesses of a child's functional performance. The entrance level of training of a skill is determined by loading various aspects of the task performance. For example, in goal-directed movements, speed or accuracy in relation to distance and target size can be examined. By varying task loads during the functional assessment, the therapist can analyze which aspects of the task performance are most critical. Moreover, training of tasks with regard to these critical factors will tap the motor control processes that are thought to be involved. For instance, when a motor pattern for throwing an object is not yet developed, the child is given practice trials. To develop a throwing pattern, a variety of objects with which to practice are provided. Alternatively, if a child can catch a ball only when standing still and warned beforehand, training focuses on ball catching in complex and attention-demanding situations. Once the child has discovered a reasonably effective approach to the desired movement, (10) a demand for parameters gradually is introduced by propelling the object over various distances or by aiming the object at targets of different sizes. Toward the end of training, the therapist will examine whether the skill can be performed automatically by talking about something else or by combining it with a new task.

During their training on NTT, physical therapists are encouraged to motivate children to learn and to provide specific instructions and feedback to the children. They can choose among different learning options, such as implicit, guided discovery or explicit learning. If explicit learning is chosen, they know that different stages of motor learning are involved: the cognitive phase, the associative phase, and the autonomous phase. (11) Neuromotor task training emphasizes giving the child some sort of idea or image of the task to be learned, be it through verbal instructions or demonstrations. Schmidt and Lee (6) reported that clear instructions about what task to perform, how to perform it, and what to attempt to achieve as a score are critical for motor learning. Less effective are instructions such as "go" or "OK." Therefore, NTT therapists are trained to give instructions (clues) that provide useful and important information about the movement itself or to stress ways in which children can recognize their own errors. After a motor task is performed, providing feedback about what was done may be essential for skill learning. Physical therapists can talk about the outcome of a movement (results) or about the nature of the movement pattern (performance). In NTT, the provision of adequate feedback on performance is encouraged because it may enhance motor learning, especially in children with motor problems. (6-8) Both the motivational and the informational functions of feedback are emphasized in NTT.

Schoemaker et al (2) showed that the use of NTT in the treatment of children with DCD had positive effects on handwriting and on fine and gross motor skills. Children with DCD improved their motor performance after 9 intervention sessions, whereas children in a nonintervention group did not improve spontaneously in 9 weeks. Niemeijer et al (12) described the different therapeutic teaching principles that physical therapists actually use while treating children with DCD during 30-minute sessions of NTT. Although physical therapists aim to enhance motor learning by using these principles, there is no empirical clinical evidence that these mechanisms have positive effects. Niemeijer et al (12) showed that the therapists' use of principles varied but was not associated with a child's initial level of motor performance on the Movement Assessment Battery for Children (13) (M-ABC) or the second edition of the Test of Gross Motor Development (14) (TGMD-2). These findings indicated that a child's initial motor performance level does not influence a therapist's verbal actions aimed at improving the child's motor performance. In this pilot study, we investigated whether the frequency of use of particular teaching principles is associated with an improvement in children's motor performance on the M-ABC and the TGMD-2.

Method

Sample Selection and Description

Forty therapists, all registered in the Netherlands as pediatric physical therapists, were willing to participate. They learned NTT during their 3-year training and 2 extra meetings organized especially for the purpose of this study. An update on NTT was given during the first meeting. Next, the therapists recorded an intervention session on videotape while treating a child with DCD. At the second meeting, the videotapes were used to stress the NTT principles in their interventions.

Children could be included in this study if they fulfilled the 4 criteria for DCD in the Diagnostic and Statistical Manual of Mental Disorders, 4th ed, text revision (Tab. 1), (15) if they were recently referred for physical therapy, if they had no history of physical therapy, and if their parents gave informed consent. They had to be referred for physical therapy by their general practitioner because of motor coordination problems in school or at home. This criterion indicated that their poor motor coordination interfered with activities of daily living (criterion B (15)). The therapists examined the children with the General Psychomotor Assessment Protocol for DCD (16) to exclude obvious neurological disorders or other medical conditions that could explain the motor difficulties (criterion C (15)). As part of this protocol, the M-ABC was administered, and a score at or below the 15th percentile confirmed that the child's motor coordination was substantially below that expected for his or her age (criterion A (15)). All children attended mainstream Dutch schools, a factor that indicates that their intelligence was within the normal range (criterion D (15)). Because this study investigated treatment effects through measurement of the progression of motor performance by independent researchers, a child also had to perform below the age-appropriate 15th percentile of the M-ABC during the researchers' pretest assessment to be included in this study.

After a recruitment period of 2 years, 19 children and 11 physical therapists participated in this study. The therapists were all female and between 37 and 53 years of age. The children scored below the 15th percentile on the M-ABC during the researchers' pretest assessment. Sixteen boys (one aged 5 years, six aged 6 years, four aged 7 years, four aged 8 years, and one aged 10 years) and 3 girls (6, 8, and 9 years of age) participated. Their mean age was 7 years 5 months (SD = 1.3 years). None of them was diagnosed by a psychiatrist as having attention-deficit/hyperactivity disorder or a pervasive developmental disorder.

Measurement Instruments

The motor teaching principles taxonomy (12) (MTPT) was used to register the type and frequency of therapists' verbal actions aimed at improving motor learning. The MTPT is a well-structured observation system developed to analyze videotaped recordings of NTT intervention sessions. The development of the MTPT was based on scientific motor learning information emphasized in NTT and on the observed (verbal) actions of therapists. The therapists' overt actions can be clustered into 3 major categories, covering 20 different teaching principles (Tab. 2). These categories are mutually exclusive and exhaustive. The reliability of categories and their individual principles in the MTPT is satisfactory. (12) The verbal actions of therapists are registered only once if the therapists repeat an action because the child does not react. Thus, for example, the frequency of instructions given is related directly to the child's number of practice trials. The Cohen kappa values for test-retest reliability were between .69 and .79 for the "giving instruction" category, between .73 and .85 for the "sharing knowledge" category, and between .63 and .99 for the "providing or asking for feedback" category. For interrater reliability, they were between .60 and .77.

The M-ABC provides an indication of a child's motor functioning in daily life. (13) It was validated for the Dutch population by Smits-Engelsman. (17) The M-ABC consists of 4 age-related batteries with norms. Each battery consists of 8 motor tasks that measure different aspects of motor ability; 3 items measure manual dexterity, 2 items measure ball skills, and 3 items measure static and dynamic equilibrium. A lower score represents a better performance. When a child is tested with the appropriate age range and norms, a score at or below the 15th percentile means poor performance in comparison with that of peers. The standardized scores make comparisons within a broad age range possible. The test is product oriented, as it measures motor competence in outcome terms (eg, speed and amount of successful attempts). This test often is used to classify DCD (18) and to measure treatment effectiveness. (18,19)

The reliability and validity studies reported for the M-ABC are based primarily on its predecessor, the Test of Motor Impairment. (13) The minimum test-retest reliability at any age was .75, and the interrater reliability was .70. The decision agreements of the total scores were 97% for age 5 years, 91% for age 7 years, and 73% for age 9 years. Thus, the test has moderate to good validity and reliability. The standard error of measurement (SEM) (test-retest) was 3.13 points; the mean total scores ranged from 13.2 to 15.4, and the standard deviations ranged from 3.9 to 7.5. (19) The least detectable difference (LDD) between 2 scores thus was 8.68 (1.96 x [square root of 2] x SEM). Retesting within 2 weeks has shown effects of learning. (19) Therefore, for monitoring of an individual child, it is recommended that measurements be obtained twice at the beginning of therapy and that the first measurement be discarded. (19) Although the M-ABC is used for evaluation purposes, (18,19) specific evidence of its sensitivity to change or responsiveness has not yet been published. In the present pilot study, the therapists used the M-ABC as an identification instrument for children with DCD. In addition, the researchers used it as an evaluation instrument (pretest and posttest).

The TGMD-2 assesses gross motor functioning with 2 subtests: locomotor and object control. (14) A total of 12 gross motor skills that usually are acquired by children in preschool and early elementary grades are measured. For each skill, there are 3 to 5 performance criteria, and their observation leads to a raw score. A higher score indicates a better quality of movement patterns. The TGMD-2 provides age-related standardized scores for each subtest, with a mean of 10 (SD=3). Both standardized scores can be converted into a composite gross motor quotient (GMQ), with a mean of 100 (SD=15). The TGMD-2 possesses a high degree of reliability and little test error. (14) Interscorer reliability and stability-overtime reliability coefficients varied between r=.88 and r=.98 for both the locomotor and the object control subtests and the GMQ. The SEM is 5 GMQ points for children above the age of 5 years. (14) In the present pilot study, the TGMD-2 was added to the protocol because this test evaluates how a skill is performed or the quality of movement patterns responsible for the performance outcome, (20) rather than the product evaluated by the M-ABC.

Protocol

Before treatment started, the researchers tested the children with the M-ABC and the TGMD-2. The raters received training to increase the reliability of test examinations. They all recorded a test session on videotape. The first author decided whether the motor assessments were in line with the guidelines for test administration as described in the manuals. The raters did not look into files to find out whether the child had been tested before or what the test scores had been. The M-ABC was administered twice before treatment, first by the therapist identifying the child with DCD and second by the researchers during the pretest assessment. Through this procedure, chances that improvement between the pretest and posttest M-ABC scores would be attributable to test-retest effects were reduced. (19) After 9 weekly half-hour sessions of NTT, the researchers tested a child 1 to 2 weeks later (posttest assessment). Because physical therapists in the Netherlands can apply for payment of additional sessions after the first 9 sessions, a second posttest assessment was conducted after 18 sessions if a child received prolonged treatment.

The researchers videotaped one 30-minute session of NTT for each child-therapist relationship. They made the recordings after the child had received at least 6 sessions, so as to intrude as little as possible in the treatment situation. By now, the child had become acquainted with the therapist, the room, and the material. In addition, the therapist had set goals for the intervention. The therapists did not know what purpose the videotape recordings were to serve; they knew only that the researchers wanted to know more about what was actually practiced during the sessions. The researchers who had developed the MTPT analyzed the videotapes. To obtain the most consistent judgment over different videotapes, we used the MTPT frequencies from the researcher with the highest test-retest reliability (Cohen kappa values were .69-.79 for "giving instruction," .81-.85 for "sharing knowledge," and .66-.99 for "providing or asking for feedback"; the interrater reliability was .60-.77).

Data Analysis

In this study, t tests were used for M-ABC and TGMD-2 data from all 19 children seen on 2 test occasions, and repeated-measures analyses of variance were used for data from 13 children tested 3 times (SPSS version 11 *). To examine the degree to which the applied motor teaching principles (with often-skewed distributions) were associated with positive treatment effects, we analyzed the data in 2 ways: difference scores (children's posttest minus pretest scores) were calculated, as this is the most straightforward method for measuring change, (21) and these scores were nonparametrically (Spearman rank) correlated with MTPT frequencies (SPSS version 11); and the change over time was modeled between and within children. (22) For this latter approach, at least 3 measurement occasions are needed; these were available for our data from 13 of 19 children. Simple multilevel regression analyses (MLwiN 1.1 ([dagger])) were performed on all of the available data (51 measurement occasions for 19 children; the "missing" 6 occasions were not a problem) to investigate a linear effect of the MTPT variables on M-ABC or TGMD-2 over time, with the child's age as a covariate. We standardized the regression weights: [SD(x)/SD(y)] x regression weight. (23) Motor learning on the M-ABC was enhanced when a negative association was found. For the TGMD-2, however, the same was true when a positive association was found. Because of our small sample size and multiple tests for significance, the alpha level was set at .05.

Results

Table 3 shows the children's mean pretest and posttest scores on the M-ABC and the TGMD-2. A statistically significant improvement between pretest and posttest scores was found. No statistical difference was found between pretest or first posttest scores for children who did (n=13) or children who did not (n=6) receive additional sessions. Post hoc analyses of the group of 13 children tested 3 times showed that improvement was statistically significant between the first and second measurement occasions (M-ABC: [t.sub.12]=2.58, P=.02; TGMD-2: [t.sub.12]= -3.46, P=.05) but not between the second and third test occasions. At the individual level, we found that 7 of the 19 children showed changes that exceeded the LDD (1.96x[square root of 2]xSEM) on the M-ABC and that 9 showed an improvement of 1 LDD or more on the TGMD-2.

Tables 4, 5, and 6 show means and standard deviations for individual principles within the 3 MTPT categories that were provided in 30-minute NTT intervention sessions. These tables show how frequently therapists gave information on what to do (giving instruction), talked about movement tasks and execution of motor tasks before or during the execution of a movement (sharing knowledge), and provided feedback or asked the child to give feedback.

Tables 4, 5, and 6 also show the different measures of association between the categories of teaching principles within the MTPT and the children's changes on the M-ABC and the TGMD-2. The 95% confidence intervals of the Spearman rank correlations were broad. For example, "giving clues" was associated with improvement on the TGMD-2 after 9 sessions (n=19, r=.52, 95% confidence interval=.10-.79, P=-.01).

Discussion and Conclusion

The aim of this pilot study was to examine whether different types of teaching principles used by physical therapists were associated with therapeutic effectiveness. On both motor tests, performance improved more than 1 standard deviation for the treated group as a whole, and about one third of the children showed an improvement of 1 LDD or more. The mean M-ABC score improved from a score at the 1st percentile (very poor) to a score representing the 15th percentile (boundary with normal range). The mean TGMD-2 score improved from a score at the 2nd percentile (poor) to a score representing the 10th percentile (below average).

Although we detected statistically significant differences in response to treatment, we have no data to assist with the interpretation of the clinical meaningfulness of these changes. Nonetheless, 2 methods of investigating the relationship between teaching principles and changes with intervention determined that 4 principles were associated with improved performance on the TGMD-2 (giving clues, explaining why, providing rhythm, and asking about understanding) and that 2 principles were associated with improved performance on the M-ABC (adjusting body position and explaining why).

Two principles associated with treatment effects were categorized as "giving instruction" in the MTPT: giving clues and adjusting body position. Therapists gave clues, that is, instructions that provided useful and important information about the motor task. Most of the instructional clues were aimed at improving the quality of motor patterns, such as "can you try to bend your knees when you jump?" This factor makes the TGMD-2 sensitive to therapeutic success by using the teaching principle of giving clues. The M-ABC assesses motor competence through the time a child needs to execute a movement or the accuracy of the child's movements. These outcome aspects of movement execution are not necessarily improved when children have to focus on the quality of their movement performance. (24) The present findings indicate that motor patterns improve if children receive clues about how to perform a movement. Schmidt and Lee (6) reported that giving clues is one of the best ways to instruct a skill, as opposed to commands such as "do your best" (instructions with a general goal), because giving clues focuses an individual's activities and serves as a reference against which achievement can be compared. However, Wulf and Weigelt (24) showed that giving body-related instructions to adults degraded their learning of a ski simulation task compared to giving no instructions. For motor learning in adults, providing an external focus of attention, such as a cue, is thought to be beneficial in terms of both outcome of movement performance and movement patterns. (25,26) Shea and Wulf (26) theorized that it is probably better to perform a movement without being too concerned about the body movements, as conscious control may interfere with control processes that would otherwise regulate the movement automatically. It is unclear whether the children with DCD in this study needed clues as cues because their motor learning processes were not automatically regulated or whether they needed cues to help them focus on a specific aspect of the task instead of on all aspects at the same time (eg, internal or external, visual, or kinesthetic). Nevertheless, the present findings may confirm the idea that children with DCD need formal instruction on how to perform a task. The quality of their movement patterns was higher when they received more verbal clues about how to perform a task.

Another instructional principle found to be significantly associated with improvement was adjusting body position to make a desired action possible. For example, when the child prepares for a writing task, the therapist puts the child's arm in a "correct" position without explanation. With this action, the therapist physically guides the child. Theoretically, there are opposing views as to whether or not guidance should be effective in producing learning of the main task. (6) Guidance can prevent making errors and can have positive effects on the task learned. However, it also can prevent the learner from learning from errors; therefore, transfer of learning may not be as effective when practicing with guidance as when practicing without guidance. In the present pilot study, physical therapists guided the children through tasks other than those assessed during the posttest assessments. Therefore, the results indicate that guidance in the form of correcting posture may have positive effects on children with DCD.

Three principles in the category of "sharing knowledge" were found to be statistically significant: explaining why it is better to execute a movement in a certain way, providing rhythm or timing, and asking whether the child understands the movement task. In another promising treatment approach, the cognitive orientation to daily occupational performance (CO-OP), emphasis is placed on teaching children to plan and evaluate their own movements. (3,27) Mandich et al, (28) who performed in-depth videotape analyses of CO-OP, found that many children with DCD lacked an understanding of the motor requirements of a task. They interpreted the therapists' provision of this knowledge as a prerequisite for the use of the cognitive strategies of CO-OP. Their observations and the results of the present pilot study indicate that talking (sharing knowledge) about motor tasks or movement execution with a child with DCD enhances the child's motor performance.

Although this study was a pilot study, we were able to detect some statistically significant associations. However, it is important to realize that the power to find significant correlations with a clinically relevant medium effect size (>.30) was only .36 with 19 participants and only .26 with 13 participants. (29) To detect a medium effect size with a power of .80 (one-tailed alpha level set at .05), information would be needed on treatment effects and teaching principles used in 68 children. (29) Therefore, the present results only show that children who were taught through the teaching principles identified in this study were more likely to improve their motor performance, that is, to show more treatment success, than others.

Two methods were used to analyze our data. Although the use of difference scores has been debated, (22) they were used in the present study because they are the most straightforward measures of change. The disadvantage of using difference scores is the unreliability of the measured scores, as these are never the true scores, and the measurement error is compounded. This unreliability makes it difficult to detect effects statistically. Another disadvantage is their relationship to initial status. As is often seen, people with the poorest performance improve the most. (21) This tendency also was found in the present study, although 2 children who performed very poorly did not benefit more from treatment than others. Nevertheless, the same pattern of results was found with separate multilevel analyses used to model the change over time between and within children on each of the performance tests. Although we restricted ourselves to possibly too simple multilevel analyses, without exploiting other possibilities, such as random effects or model selection, for which we believed the data were insufficient, we were encouraged by the similarity of the results obtained by the 2 different methods.

Further research with more participants is necessary to determine whether the nonsignificant findings resulted from low power. Because participation takes time that some children and parents lack, multiple measurement occasions are needed for more children to model the change over time in a more powerful way. Because it is of clinical importance, more insight also should be gained with regard to how the change in motor abilities influences the participation of children with DCD in, for example, activities at recess in the school yard. In addition, more research is needed to obtain information on how physical therapists use teaching principles during subsequent sessions. A limitation of the present study design is that it does not provide evidence for a causal role of teaching principles in therapeutic success. The teaching principles used in this study were not randomly assigned to the children; therefore, we cannot rule out the possibility that certain child characteristics, such as hyperactivity or introversion, influenced the tutoring style of the therapists. In future studies, we would like to assign children randomly to a few different therapists to determine to what extent the use of teaching principles is therapist related or results from the interaction with the child.

Although this pilot study has limitations, physical therapists may benefit from the results, as the results may raise their awareness and provide insight on how to influence motor learning in children with DCD. Still, caution is warranted because the study was based on a small sample size (resulting in low power to find significant associations), broad age ranges, and information on physical therapists' teaching principles during middle practice sessions only. The results suggest what many people already knew intuitively: children with DCD need formal instruction.

This article was received May 14, 2005, and was accepted March 28, 2006.

References

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The Bottom Line

The Bottom Line is a translation of study findings for application to clinical practice. It is not intended to substitute for a critical reading of the research article. Summaries are written by members of The Bottom Line Committee.

[Niemeijer AS, Schoemaker MM, Smiths-Engelsman BCM. Are teaching principles associated with improved motor performance in children with development coordination disorder?

What problems did the researchers set out to study, and why?

In general, there has been a paucity of research on effective interventions for children with developmental coordination disorder (DCD). Recently, several intervention strategies using a "top-down" approach were described and found to be associated with positive treatment effects. One of these strategies--neuromotor task training (NTT-)--incorporates motor learning principles and emphasizes direct teaching of task-specific activities. Because a variety of options can be used to accomplish effective teaching, little is known about which specific teaching principles are associated with the improvements seen in motor skills, so these authors explored the interaction between specific NTT teaching principles and improved motor skills.

What types of patients participated in the study?

Nineteen children (16 boys, 3 girls) with a diagnosis of DCD (according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th ed) who were referred for physical therapy because of motor coordination problems at home or school. The children were between the ages of 5 to 10 years (mean=7 y, 5 mo; SD=1.3 y). Participation in the study was limited to children who performed below the 15th percentile on the Movement Assessment Battery for Children (M-ABC) pretest assessment.

What new information does this study offer?

Children with DCD are heterogeneous with respect to the prevalence and severity of the motor impairments and functional limitations that characterize the disorder as well as the nonmotor impairments. Approaches to treatment have been equally diverse. These authors delineated which of the various teaching principles available to therapists using NTT were associated with the greatest gains in motor skills on the M-ABC or the Test of Gross Motor Development (TGMD-2). They found that improved motor skill performance was associated with specific clues on how to perform the task and guidance in terms of correcting posture. Improvements also were associated with principles that provided explanations for the execution of specific movements and with strategies in which the children were asked if they understood the movement requirements of the task.

How did the researchers go about the study

All study participants received a 30-minute session of N-FI once a week for 9 weeks. Posttest assessments using the M-ABC and TGMD-2 were done 1 or 2 weeks after the 9th session. Thirteen of the 19 study participants received an additional 9 sessions, after which a second posttest assessment was done. After participants had gone through at least 6 sessions, the researchers videotaped one of the 30-minute NTT interventions and analyzed the session using an observation system that quantified the type and frequency of the various motor teaching principles associated with N-FI. These investigators developed and validated this observation system, called "motor teaching principles taxonomy" (MTPT), which essentially clusters 20 different principles for teaching motor skills into 3 mutually exclusive categories. Therapeutic success was measured by change scores on the M-ABC and TGMD-2 for each child. The change scores between and within children were analyzed with respect to their association with the teaching principles.

How might the results of this study apply to patients who are treated by physical therapists from this point forward?

At a minimum, this study reinforces the idea that children with DCD benefit from task-specific instruction. The NTT is a task-oriented, skill-based approach and relies on therapists applying effective teaching principles for giving instructions and providing feedback. By using the MTPT, they were able to parse the teaching principles used in N-FT into component parts, giving physical therapists more insight into which might be more successful than others in achieving improved motor skills. Task-oriented approaches to motor learning and control, while having a strong theoretical basis, can be left to interpretation. By defining and categorizing intervention strategies, therapists can begin the challenging work of matching specific interventions to the various subtypes of DCD.

What are the limitations of the study, and what further research is needed?

As the authors acknowledged, this pilot study was done with a small sample and without a comparison group; all subjects received NTT, but there were differences in the type and frequency of the various motor teaching principles. No attempt was made to control for the variety of child-related factors that could have contributed to improved scores on the M-ABC and TGMD-2. Although a statistically significant improvement was found between pretest and posttest scores on both outcome measures, it is difficult to establish any causality with the teaching principles used in the NTT. Another limitation of the study was the uneven application of intervention sessions; subjects received either 9 or 18 sessions based on availability of reimbursement. The major limitation, however, is that the main result of the study was based on observation data from one treatment session. It is difficult to find clinical significance in the reported interactions between motor outcome and use of specific teaching principles from one 30-minute occurrence.

Further research is needed with a larger group of subjects and with a comparison group so that the improvements in motor performance can be linked to specific interventions. In addition, increasing the number of coded observations is necessary to establish a true correlation with the treatment outcomes. Finally, this field of study will benefit greatly from studies looking at motor skill retention over a longer period of time, so that treatment success can include permanent changes in motor behavior.

* SPSS Inc, 233 S Wacker Dr, Chicago, IL 60606.

([dagger]) Centre for Multilevel Modelling, University of Bristol, 35 Berkely Square, Bristol, BS8 1JA United Kingdom.

Anuschka S Niemeijer, Marina M Schoemaker, Bouwien CM Smits-Engelsman

AS Niemeijer, MSc, is a doctoral candidate at the Center for Human Movement Sciences, Northern Centre for Healthcare Research, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.

MM Schoemaker, PhD, is Associate Professor, Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, PO Box 196, 9700 AD Groningen, the Netherlands. Address all correspondence to Dr Schoemaker at: [e-mail].

BCM Smits-Engelsman, PT, PhD, is Professor, Avans+, University for Professionals, Breda, the Netherlands, and Motor Control Lab, Faculty of Kinesiology and Rehabilitation Sciences, Department of Kinesiology, Katholieke Universiteit Leuven, Leuven, Belgium.

All authors provided concept/idea/research design, project management, and facilities/equipment. Ms Niemeijer provided writing, data collection and analysis, and subjects. Dr Schoemaker and Dr Smits-Engelsman provided fund procurement, institutional liaisons, and consultation (including review of manuscript before submission). The authors acknowledge the important discussions with Dr Koop Reynders, several graduate students who helped with the data collection, and Dr Marijtje van Duijn for her statistical advice. They thank the therapists who were willing to participate and have their daily professional activities registered on videotape. They also thank the children for their contributions. Finally, they thank the Dutch Health Care Insurance Board, which funded this research.

The Medical Ethics Committee of University Medical Center Groningen approved the study.

Table 1.

Diagnostic Criteria for Developmental Coordination Disorder (15(p58))

Criterion   Description

A           Performance in daily activities that require motor
              coordination is substantially below that expected
              given the person's chronological age and
              measured intelligence. This may be manifested
              by marked delays in achieving motor milestones
              (eg, walking, crawling, sitting), dropping things,
              "clumsiness," poor performance in sports, or
              poor handwriting.

B           The disturbance in criterion A significantly interferes
              with academic achievement or activities of daily
              living.

C           The disturbance is not due to a general medical
              condition (eg, cerebral palsy or muscular
              dystrophy) and does not meet the criteria for a
              pervasive developmental disorder.

D           If mental retardation is present, the motor difficulties
              are in excess of those usually associated with it.

Table 2.

Motor Teaching Principles Taxonomy: Three Categories With Principles
Covering Verbal Actions of Physical Therapists Aimed at Improving
Motor Learning (12)

Category              Description

Giving instruction    Giving information on what to do
                        Give commands
                        Draw attention to and demonstrate a movement
                        Give clues on how to execute a movement
                        Adjust body position to make a desired
                          action possible
Sharing knowledge     Talking about movement tasks and execution
                          (before or during execution)
                        Explain why it is better to execute
                          a movement in a certain way
                        Revert to earlier trials
                        Tell what the child is doing
                        Provide rhythm or timing
                        Explain the difficulty of a task
                        Ask the child about the difficulty of a task
                        Ask the child if he or she understands a task
                        Ask the child if he or she thinks that he or
                          she can perform a task (attainability)
                        Ask the child questions about the movement
                          execution of a task

Providing or asking   Providing comments or asking for comments
  for feedback            after the task is completed
                        Tell the child what was done right during
                          the execution
                        Tell the child what was done wrong during
                          the execution
                        Tell about the results of performance
                          neutrally
                        Tell about the positive results of movement
                        Tell about the negative results of movement
                        Ask the child's opinion about the movement
                          execution
                        Ask the child's opinion about the results
                          of the task

Table 3.

Scores on the Movement Assessment Battery for Children (M-ABC)
and the Second Edition of the Test of Gross Motor Development (TGMD-2)
for the Entire Group (n=19) and for the Subgroup (n=13) That Received
18 Sessions of Neuromotor Task Training (NTT)

                 [bar.X] [+ or -] SD Score
                 Pretest
                 Before NTT           Test 2-
Test             (Test 1)             Test 1

M-ABC
  Entire group   16.4 [+ or -] 5.3    -5.3 [+ or -] 7.7
  NTT subgroup   16.6 [+ or -] 6.1    -5.5 [+ or -] 7.6

TGMD-2
  Entire group   73.5 [+ or -] 11.9    9.6 [+ or -] 10.7
  NTT group      70.2 [+ or -] 12.2   10.1 [+ or -] 10.6

                 [bar.X] [+ or -] SD Score
                 Posttest After
                 9 Sessions

Test             (Test 2)

M-ABC
  Entire group   11.0 [+ or -] 7.8
  NTT subgroup   11.1 [+ or -] 8.8

TGMD-2
  Entire group   83.1 [+ or -] 8.9
  NTT group      80.4 [+ or -] 7.5

                                      Posttest After
                 Test 3-              18 Sessions
Test             Test 1               (Test 3)

M-ABC
  Entire group
  NTT subgroup   -6.7 [+ or -] 4.0    10.0 [+ or -] 6.2

TGMD-2
  Entire group
  NTT group       10.4 [+ or -] 10.3   80.6 [+ or -] 7.7

                 Paired-Samples
                 t-Test Value or
                 Repeated Measures
Test             F Value (P)

M-ABC
  Entire group   t (18) = 3.0 (.007)
  NTT subgroup   F (2,11) = 18.4 (.001)

TGMD-2
  Entire group   t (18) = -3.9 (.001)
  NTT group      F (2,11) = 6.4 (.014)

Table 4.

Mean Number of Times That Teaching Principles of the Motor Teaching
Principles Taxonomy (MTPT) Category of "Giving Instruction" Were
Used and Data Analyses (a)

                                     M-ABC

                                     [r.sub.s]   [r.sub.s]
                       [bar.X]       for 2-1     for 3-1
Principle              (SD)          (n=19)      (n=13)      ML

Total instructions
  given                37.7 (11.0)   -.17        -.08        -.04
Give commands          18.8 (8.2)    -.03        -.18        -.13
Demonstrate             3.4 (3.9)    -.11        -.02        -.18
Give clues             12.7 (5.6)     .34         .46         .10
Adjust body position    2.8 (5.1)    -.09        -.48 (b)    -.34 (b)

                       TGMD-2

                       [r.sub.s]     [r.sub.s]
                       for 2-1       for 3-1
Principle              (n=19)        (n=13)      ML

Total instructions
  given                 .16           .27         .17 (b)
Give commands           .13           .24         .19
Demonstrate            -.17           .04         .05
Give clues              .52 (b)       .46 (b)     .37 (b)
Adjust body position   -.15          -.02        -.12

(a) M-ABC=Movement Assessment Battery for Children, TGMD-2=Second
Edition of the Test of Gross Motor Development, ML=multilevel
regression weight, 2-1=posttest score minus pretest score,
3-1=second posttest score minus pretest score.

(b) Significantly associated with improvement
(P [less than or equal to] .05).

Table 5.

Mean Number of Times That Teaching Principles of the Motor Teaching
Principles Taxonomy (MTPT) Category of "Sharing Knowledge" Were
Used and Data Analyses (a)

                                     M-ABC

                                     [r.sub.s]   [r.sub.s]
                       [bar.X]       for 2-1     for 3-1
Principle              (SD)          (n=19)      (n=13)      ML

Total shared
  knowledge            22.4 (10.6)    .16        -.16         .02
Explain why             3.2 (3.5)    -.21        -.46 (b)    -.26 (b)
Revert to earlier
  trials                2.7 (2.9)    -.09        -.51 (b)    -.05
Tell what is
  being done            2.3 (2.3)    -.01        -.25        -.11
Provide rhythm
  or timing             0.16 (0.4)    .03         .08         .20
Explain difficulty      2.8 (2.6)     .21        -.01         .06
Ask about difficulty    1.5 (2.0)     .19         .10         .10
Ask about
  understanding         0.4 (0.7)     .05        -.04         .07
Ask about
  attainability         3.3 (3.1)     .41         .30         .23
Ask about movement
  execution
  of a task             6.0 (5.6)     .29         .006        .08

                       TGMD-2

                       [r.sub.s]     [r.sub.s]
                       for 2-1       for 3-1
Principle              (n=19)        (n=13)      ML

Total shared
  knowledge            -.34           .18         .21
Explain why             .02           .46 (b)     .23 (b)
Revert to earlier
  trials               -.23          -.02        -.10
Tell what is
  being done           -.25           .10        -.14
Provide rhythm
  or timing             .16           .46 (b)     .30 (b)
Explain difficulty     -.13           .30         .016
Ask about difficulty   -.25          -.01        -.08
Ask about
  understanding        -.15           .59 (b)     .23 (b)
Ask about
  attainability         .12           .52 (b)     .16
Ask about movement
  execution
  of a task            -.21          -.23        -.21

(a) M-ABC=Movement Assessment Battery for Children,
TGMD-2=Second Edition of the Test of Gross Motor Development,
ML=multilevel regression weight, 2-1=posttest score minus
pretest score, 3-1=second posttest score minus pretest score.

(b) Significantly associated with improvement
(P [less than or equal to] .05).

Table 6.

Mean Number of Times That Teaching Principles of the Motor Teaching
Principles Taxonomy (MTPT) Category of "Providing or Asking for
Feedback" Were Used and Data Analyses (a)

                                     M-ABC

                                     [r.sub.s]   [r.sub.s]
                       [bar.X]       for 2-1     for 3-1
Principle              (SD)          (n=19)      (n=13)      ML

Total amount of
  feedback             23.1 (10.1)   -.07        -.04        -.11
Tell what was done
  right                 2.5 (2.3)    -.22         .08        -.25
Tell what was done
  wrong                 2.2 (2.9)    -.16         .13         .03
Tell results
  neutrally             3.2 (3.3)    -.34         .09        -.28 (b)
Tell positive
  results               7.6 (3.8)    -.11        -.26        -.16
Tell negative
  results               1.9 (1.5)     .18        -.02         .02
Ask opinion of          3.4 (3.8)     .16         .11        -.02
  performance
Ask opinion of
  results               2.4 (2.4)     .24        -.51 (b)    -.17

                       TGMD-2

                       [r.sub.s]     [r.sub.s]
                       for 2-1       for 3-1
Principle              (n=19)        (n=13)      ML

Total amount of
  feedback             -.26          -.01        -.05
Tell what was done
  right                -.21          -.07         .23
Tell what was done
  wrong                 .17           .34         .18
Tell results
  neutrally            -.26          -.03        -.10
Tell positive
  results              -.15           .14        -.01
Tell negative
  results              -.23          -.33        -.15
Ask opinion of         -.29          -.28        -.27
  performance
Ask opinion of
  results              -.51          -.46        -.15

M-ABC=Movement Assessment Battery for Children, TGMD-2=Second
Edition of the Test of Gross Motor Development, ML=multilevel
regression weight, 2-1=posttest score minus pretest score,
3-1=second posttest score minus pretest score.

(a) Significantly associated with improvement
(P [less than or equal to] .05).