Federal legislation in the United States protecting the rights of all children and youth to an appropriate education, including access to pediatric therapy, is extended to infants and toddlers. Although state, federal, insurance, and private monies are expended for infants and children with developmental delays, research evidence remains inconclusive on the best treatment for infants with gross motor delays.
Neurodevelopmental treatment (NDT) for infants is an approach commonly used by pediatric therapists for infants with posture and movement dysfunction. Despite the widespread use of NDT in pediatric therapy, few well-designed studies exist that systematically investigate the short- or long-term benefits of the NDT approach for infants. Authors of meta-analytic reviews1–5 report positive trends, but inconclusive evidence, on the efficacy of NDT in improving independent functional movement and postural control for infants and children with cerebral palsy (CP) or with high risk factors predisposing them to CP. As a commonly used approach in pediatric therapy, it is important that we have more definitive research on the efficacy of the NDT treatment approach for infants.
Eight randomized controlled trial (RCT) studies6–13 on the efficacy of early therapy for infants were identified in the literature in the last 20 years. Five of the RCT studies6,7,10–12 were conducted with infants younger than 1 year as subjects. The participants in these five studies were infants born prematurely and identified by high risk factors predisposing them to the development of CP. Researchers in three of the RCT studies6,7,12 reported in subsequent articles8,9,13 results of extended follow-up (FU) for the same infant populations. With the exception of one study12 that used a combination of NDT and sensory integration (SI), no treatment was investigated in these studies other than the NDT approach. Except for the Girolami and Campbell study,10 the NDT therapy was vaguely defined with no identified protocol and therapy providers were not cited as having received specific NDT infant training. All investigators in the eight RCTs6–13 examined the following question: Does early pediatric therapy intervention improve outcomes for infants with high risk for CP?
Researchers in four of the five studies6–9,11–13 reported nonsignificant results on the efficacy of pediatric therapy to improve outcomes for infants with high neuromotor risk on any of the postintervention outcome measures at 1 year of age,6,7,11,12 and on extended FU assessments at 18 months,12 24 months,8,12 30 months,11 4 years,13 or 6 years of age.9 In all studies, methodological problems were identified: (1) absence of identified functional delay in study participants6–9,11–13; (2) infrequency of intervention6–9,11–13; (3) lack of rater reliability and validity in outcome measures6-9,11-13; and (4) absence of operationally defined NDT intervention protocols.6–9,11–13
Girolami and Campbell10 conducted the single study that included an operationally defined NDT-protocol intervention. The NDT-protocol was delivered 12 to 15 minutes twice daily for 7 to 17 days by a Neurodevelopmental Treatment Association (NDTA) instructor with expertise in infant treatment. The researchers studied 19 infants at postconceptual ages of 34 to 35 weeks in a special care nursery. To assess postural control, they used the Supplemental Motor Test, a precursor of the Test of Infant Motor Performance (TIMP).14,15 Even with a small sample size and short intervention duration, statistical significance (P = 0.002) for improved postural control in prematurely born infants was reached in the NDT-protocol intervention for infants with high neuromotor risk compared with a matched control group who received identical amounts of attention and positioning. When the eight RCTs were compared, Girolami and Campbell’s10 was the only investigation in which a significant change was reported.
To avoid the methodological problems identified in the RCT studies6-9,11-13 discussed above, the study presented here used an operationally defined protocol, therapy providers with specialized infant training, high frequency of intervention, and a valid outcome measure for infants with posture and movement dysfunction. This study took place within the context of a 3-week NDTA Advanced Baby Course. The course was based on the NDT problem-solving process for managing sensory-motor impairments in infants aged 4 to 12 months. The general theoretical assumptions and application of the NDT approach used in the NDT Advanced Baby Course were described by Howle in 2002.16 Infants in this study demonstrated gross motor delays with posture and movement dysfunction that were characterized by impairments in orienting responses of the head and trunk.
The capacity of a single study to be used to demonstrate the efficacy of an entire approach is generally considered outside the realm of possibility in today’s research environment. An approach, such as NDT, that can be individualized to meet the needs of persons with different diagnoses across the lifespan is inherently too variable to be studied in its entirety. Instead, specific aspects of such an approach can be investigated using well-designed studies with operationally defined protocols and homogeneous participant groups.
An operationally defined protocol was used in this study specifically to address the role of trunk activities in orienting responses as they relate to functional motor skills in infants. By using an operationally defined protocol that was linked to a specific impairment common to a group of infants with posture and movement dysfunction, the authors of this study examined the efficacy of a single aspect of the NDT approach: sequenced dynamic trunk co-activation intervention. Although the trunk activation activities used in this study are not previously published as a protocol in this form, the concepts and facilitations employed in the protocol have been taught in the NDT approach and are not the original work of the authors.
This study was designed to evaluate the efficacy of a NDT-based sequenced trunk co-activation protocol for change in gross motor function in infants with posture and movement dysfunction. A group of infants who received a dynamic trunk protocol during functional activities was compared with a group of infants who received a parent-infant interaction and play protocol. The parent-infant group was used to control for attention, maturation, and environment. Both groups received study intervention in addition to their routine ongoing early intervention (EI) services by therapists and teachers.
It was hypothesized that (1) infants with posture and movement dysfunction receiving an infant NDT-based sequenced trunk co-activation (STA) protocol for 10 hours over 15 days would make greater gains in gross motor function compared to infants receiving a parent-infant play (PIP) protocol for 10 hours over 15 days; and that (2) infants with posture and movement dysfunction receiving 10 hours of an infant NDT-based STA protocol would maintain gains in gross motor function at the 3-week FU evaluation session.
A repeated-measures randomized block design was used for this study. After meeting criteria for the study, infants with posture and movement dysfunction were stratified by severity of disability, ie, mild, moderate, severe impairments. They were then randomly assigned to either a STA treatment or PIP comparison group. Infants in both groups received 10 one-hour intervention sessions over a 15-day period in addition to their routine ongoing EI therapeutic services. The outcome measure was administered before, immediately after, and 3-weeks after intervention. The duration of the study was 8 weeks. The NDT-based STA protocol intervention was employed in the treatment practicum portion of a 3-week NDTA Advanced Baby Course.
A purposive sample of convenience was used. Of the infants referred by community healthcare agencies in the greater Houston, Texas area, 19 infants between the chronological/adjusted age of 4 to 12 months with gross motor delays, parental consent, and primary care physician prescription met the inclusion criteria for the study. Infants were identified as having posture and movement dysfunction if they scored at or below the 5th percentile rank on the Alberta Infant Motor Scale (AIMS)17 and met one of the following criteria as defined by the Movement Assessment of Infants (MAI)18: (1) delay or asymmetry in lateral or extension head-orienting responses; or (2) delay or asymmetry in trunk-orienting responses. Infants with chromosomal syndromes, severe mental retardation, or congenital anomalies were excluded from the study. Distribution and degree of resistance to passive movement (high, fluctuating, and low) and the AIMS score distinguished the level of motor severity for stratification before randomization into groups.
The AIMS17 and the MAI18 are discriminative tools employed in this study to identify infants with and without posture and movement dysfunction who met the inclusion criteria. Both tools have high validity and reliability for discriminating motor behavior.17,18 The AIMS is a norm-referenced discriminative measure that identifies infants with or without delayed motor abilities.17 The MAI focuses on components of movement as well as on functional skills and is the only tool found to specifically identify postural components for head- and trunk-orienting.18
The Gross Motor Function Measure 88 (GMFM) was used to evaluate the effects of the 10 intervention sessions on gross motor skills. The GMFM is one of the few validated scales available for use as an evaluative tool to measure change in gross motor function over time for infants and children with CP.19 Russell et al19 reported intrarater and interrater reliability for repeated administration of the GMFM [intraclass correlation coefficient (ICC) r = 0.96–0.99]. They also reported a relationship between observed clinically important change, using parental and therapist judgment of the magnitude and importance of change in gross motor function, and actual GMFM-determined change. The GMFM was selected as an outcome measure in this study because it reflects both clinically important and quantitative changes.
One month before this study, two trained and experienced GMFM raters established interrater reliability using two sample GMFM videotaped testing sessions. The ICC(3,1) for these sessions was r = 0.92 to 0.97.
During the week before intervention, the GMFM was administered to study infants by the reliable rater who was masked to group assignment. Intervention for both groups was 10 one-hour sessions conducted over a 15-day period in adjacent, identical rooms. In addition to the study intervention, participants continued to receive EI therapeutic services as identified on their Individualized Family Service Plan. Parents were responsible for tracking type and frequency of the EI therapeutic services received by their infants during the study duration (Table 1).
Sequenced Trunk Activation.
Infants in the STA group received intervention delivered by pediatric physical, occupational, or speech therapists previously trained in an 8-week NDTA pediatric course. These therapists had treated infants for at least a year after the 8-week course and were pursuing specialized advanced NDT training for infants. The STA protocol intervention was embedded in the 3-week NDTA Advanced Baby Course curriculum and implemented within the treatment practicum portion of the course. All infants received an examination delivered by the practicum therapist for the purpose of intervention planning. The examination followed published NDT guidelines: (1) history and parental concerns/needs; (2) examination of functional skills in the context of life roles; (3) examination of posture and movement components, eg, alignment, weight shift, base of support, movement strategies, postural control, as they relate to functional activity skills and limitations (Appendix A, Fig. 3, Fig. 4); and (4) systems review to determine the impact of system and subsystems as they relate to functional activities and limitations, eg, respiratory, visual, cardiovascular, neuromuscular, musculoskeletal systems.16(p.181–253) Each individualized intervention plan was developed to meet the functional goals collaboratively established by the parents, therapists, and course faculty based on infant and parent needs and concerns. The intervention sessions emphasized transitional activities (eg, rolling, prone to sitting, sitting to quadruped to sitting, quadruped to standing) and followed a fluid sequence of engage, prepare, align, activate repetition, and home repetition. The STA protocol intervention was applied specifically to the “activate” portion of each activity sequence (Appendix A). Execution of the STA protocol involved (1) facilitation of a dynamic co-activation of trunk flexors and extensors in the sagittal plane that is adequate to the demands of a specific functional activity, (2) facilitation of active weight shifting in the frontal plane to produce “elongation on the weight-bearing side,” while maintaining the appropriate dynamic co-activation of trunk flexors and extensors,16 and (3) facilitation of active functional trunk rotation in the transverse plane, while maintaining dynamic co-activation of trunk flexors and extensors and active trunk elongation of the weight-bearing side. Functional trunk rotation is considered to be integral to the development of equilibrium behaviors for variability in motor responses20 and higher level balance.16(p.41) The facilitation of functional trunk rotation within each session is dependent upon the age of the infant and the specific functional skill within the chosen activity.
Each step in the STA protocol creates the base needed for the next step in the sequence. Intervention that incorporates the STA protocol produces dynamic trunk co-activation in sequenced trunk movements adequate for the demands of transitional activities. In an infant-led session, the individualized application of the protocol may seem different for each infant and vary within a session depending on the functional activity of interest to the infant.*
Parent-Infant Play Group.
Infants in the PIP group received enriched PIP activities delivered by their parents who were guided by a licensed Child Life Specialist (Appendix B). The primary aim of the PIP was parent-infant interaction and enriched directed play for visual, tactile, auditory, social, cognitive, emotional, and communication developmental skills.21 Although not individualized or specifically selected for trunk activation, all activities chosen by the Child Life Specialist were appropriate for the age group of infants and inherently encouraged motor skills, eg, head control, weight shifts in prone, reaching, and sitting, for the infant to participate in the interaction and play activities. An aerobics instructor (specialist in postpartum exercises) provided experiential exercise opportunities for parent and infant while doing activities of daily living, eg, pushing a stroller, playing with their infants, picking up and putting down their infants. Led by a psychology graduate student (mother of a child with CP), the parents also had an opportunity for parent-to-parent sharing and problem solving.
The data were analyzed using repeated-measures, nonparametric statistics. Nonparametric statistics were used because the sample was small and did not meet the assumptions of normality and homogeneity of variance required for parametric statistics. A one-tailed test of significance was congruent with the alternative hypotheses. The level of significance (alpha) was held at 0.05 to protect against a Type I error. The within-group analyses examined mean GMFM group scores over time, ie, pretest, posttest, 3-week FU, using the Friedman two-way analysis of variance by ranks statistic, χ2r, for each group. When χ2r was significant, post hoc, pairwise differences were tested with Wilcoxon signed-ranks statistic. The Mann-Whitney U test was used to detect between-group differences on the change of mean GMFM group scores, ie, pretest to posttest, posttest to 3-week FU, and pretest to 3-week FU.
Of the 19 infants randomized into two groups, only 10 infants (STA: n = 5, PIP: n = 5) completed at least 80% of the intervention sessions, attended both posttest sessions, and were included in the statistical analysis. Despite participant attrition, there was no significant difference between groups on variables that might have affected their response to intervention (Table 2).
The STA within-group mean GMFM scores (Fig. 1) were significantly different over time (P = 0.01). Post hoc comparisons for pretest to posttest STA intervention were significant (P = 0.02), and pretest to 3-week FU were also significant (P = 0.02). Although the PIP group experienced a positive trend in their GMFM scores pretest to postintervention, the within-group difference in the PIP mean GMFM group scores were not significantly different (P = 0.08) over time. The between-group difference on the change of mean GMFM group scores was significant (P = 0.048) from pretest to posttest in favor of the STA protocol group (Fig. 2). The first hypothesis that infants with posture and movement dysfunction receiving 10 hours of an infant NDT-based STA protocol would make greater gains in gross motor function compared with infants attending 10 hours of a PIP protocol group was supported.
For the STA protocol group, there was no significant difference (P = 0.25) between posttest and 3-week FU mean GMFM group scores. For the PIP group no significant difference was found between posttest and 3-week FU. The second hypothesis that the NDT-based STA protocol group would maintain motor gains at the 3-week FU session was supported.
The between-group difference of the mean GMFM change group scores, pretest to 3-week FU, was not significant (P = 0.11). The GMFM mean group scores in both groups demonstrated high within-group variance during this 3-week postintervention period. This high variance was likely responsible for the nonsignificant differences between groups, pretest to 3-week FU.
The study sample size estimate (n = 20 per group) was calculated a priori to provide 80% power at the 0.05 alpha level based on an unpaired two-group comparison of pre-to-postintervention change scores with a one-tailed hypothesis. The power calculations were based on the minimally important effect size index being “large” by Cohen’s conventions for unpaired comparisons. 22(Table C.2, p.720) This means that the study would have had an 80% chance of obtaining P ≤ 0.05 on the comparison of score changes if the true difference of the mean changes had been 0.8 times as large as the within-group variability of the changes (ie, the pooled within-group standard deviation).
Because of attrition and local policies, the analyzed sample size was 5 per group. Statistical power for this study based on the actual sample sizes of n = 5 per group, and using the a priori estimations (ie, effect size index 0.8, P < 0.05, one-tailed hypothesis) would have been approximately 31% if the estimations had been accurate. Although the sample size was smaller than originally planned, it turned out that the observed effect size was considerably larger than the original estimate. The nonparametric Mann-Whitney U statistic did reflect a significant group difference, P = 0.048, given the observed 8.2 mean group change difference (GMFM points), with an observed effect size index of 1.12. Post hoc power was 49% when computed using the observed values and actual sample sizes in the study groups. We recognize that the small sample size in this study is necessarily linked to imprecision in the point estimate of the treatment effect. Therefore, the results of this study will need replication in a future trial with a larger sample size.
Clinically Important Change.
Infants in the NDT-based STA protocol group made a mean change on the GMFM of 13.3 and the PIP group made a mean change on the GMFM of 5.1 at the end of intervention. These numerical scores used for the statistical analyses of the study do not describe the clinically important change in function that is often more relevant to parents and therapists.
Russell et al19 calculated the relationship of the actual change in GMFM scores to parental and therapist judgment of the magnitude and importance of change in gross motor function. Russell et al19 determined a “large positive change” in gross motor function as judged by parents and therapists was reflected by an actual GMFM change of 11.4 and 24.6, respectively; a “medium positive change” was reflected by an actual change of 5.2 and 7.0, respectively; and a “small positive change” was reflected by an actual change of 2.7 and 3.8, respectively. For example, the mother of an infant in this study with a 13 GMFM change score reported, “he is able to sit up now longer and not fall over. He has even been able to sit up by himself a few times. He can use his left hand now to pick up toys and it is staying open more of the time. And he is starting to try to stand up in his crib.” The mother of an infant with a 7.7 GMFM change score, pretest to posttest, reported, “he can now hold his head up when I hold him and look around. He is now rolling over from his back to stomach and trying to sit up. He is much more alert.” An infant whose GMFM change score was 0.72 after the intervention was reported by his mother to “look attentively around and laugh and smile.”
According to the findings of Russell et al,19 the STA group mean change on the GMFM of 13.3 would be described by the parents as a “large positive” change. Therapists would describe the same change as a “medium” to “large” change. The PIP group made a mean change on the GMFM at the end of intervention of 5.1. This score would be described as a “medium positive” change by the parents and a “small” to “medium” positive change by therapists.
Improvement in gross motor skills may be achieved with therapeutic intervention of high frequency and short duration for a defined population of infants using an operationally defined intervention protocol and delivered by therapists with advanced, specialized training. The investigators in this study provide evidence for infants with posture and movement dysfunction when interventions are focused on facilitation of dynamic co-activation of trunk flexors and extensors that supports the demands of a specific functional activity. The results have policy implications with regard to (1) generalized play approach delivered by early interventionists or direct intervention from licensed professionals, (2) specific protocols of intervention, and (3) quantity of therapeutic intervention.
Improvement in Motor Function
The NDT approach when applied according the published principles and assessment guidelines with intervention structured according to the sequenced trunk activation protocol seems to produce improved motor performance when provided to infants with posture and movement dysfunction characterized by impairments in head and trunk orienting responses. The specific targeting of dynamic co-activation of trunk musculature in the STA protocol produced better performance than the nonfocused activation of trunk musculature that was inherently present in the play activities used in the PIP protocol group. Even with a small sample size and short intervention duration, the researchers of this study provide statistical evidence that an operationally defined NDT-based trunk protocol may be an effective method of improving independent functional movement for infants with posture and movement dysfunction during the first year after birth.
Future research on the psychosocial ramifications of improved motor gains should include outcome variables for evaluating the relationship between improved function and other enablement dimensions, eg, family functioning and social participation. Harris,23 Ketelaar et al,24 and Jansen et al25 hypothesized that improvement in motor performance may increase family functioning and societal participation.
As described previously, one common methodological problem in infant studies of the effects of pediatric therapy6-13 has been the failure to use a homogenous group of participants. In all five infant studies,6-13 participants were selected with “high risk” medical diagnoses but without documented developmental impairments. The confounding variable of heterogeneity of participants may have contributed to nonsignificant results because the researchers may have been testing the efficacy of pediatric therapy on samples containing a majority of typically developing infants. The current study included only infants identified with homogenous postural and movement impairments and gross motor functional activity limitations.
The NDT approach hypothesizes that functional activity limitations can be linked to specific system impairments that are targeted during intervention.16 Infants in this study demonstrated gross motor delay with posture and movement dysfunction that was specifically characterized by impairments in orienting responses of the head and trunk.
Operationally Defined Protocol
The operationally defined NDT-based STA protocol used in this study specifically addressed the role of dynamic co-activation of trunk musculature in orienting responses as they relate to functional skills in infants. The use of an operationally defined protocol that is linked to a specific impairment common to a group of infants with posture and movement dysfunction can be used to examine the validity of one assumption of the NDT approach: “effective and ineffective posture and movement serve as a link between the individual’s functions and the system impairments.”16(p.98)
The researchers who conducted the current study illustrated that a specifically defined NDT-based STA protocol can be taught to multiple professionals within the context of a continuing education environment. In addition, we believe this operationally defined protocol will reduce variability and allow replication of the study, important for continuing investigation of the NDT approach for infants.
The PIP protocol was used to control for attention, maturation, and environment. Although it inherently included motor activities, the PIP protocol was not designed to be equivalent to the STA protocol with respect to individualized trunk activities. Future research to evaluate the effects of a generalized play intervention including trunk focused play activities delivered by early interventionists and compared to an individualized trunk activation intervention delivered by NDT infant-trained therapists could address other aspects of EI service models.
Frequency of Intervention
The authors suggest that a short-duration, high-frequency NDT-based STA protocol intervention may produce clinically important changes for infants of ages 4 to 12 months with posture and movement dysfunction. Piper’s 1990 review of the literature26 indicated that physical therapy was more effective in promoting motor milestone development if administered at least twice weekly. Results of improved motor function with higher frequency NDT intervention for children with CP are corroborated by other researchers, eg, Mayo,27 Bower and McLellan,28 Bower et al,29,30 Mahoney et al,31 Trahan and Malouin,32 and Tsorlakis et al.33 Continued research examining the optimal intervention frequency and duration for infants with posture and movement dysfunction is recommended.
Routine Therapeutic Intervention
Throughout the duration of the study, the infants in both groups continued to receive ongoing EI therapeutic services. Both groups improved their GMFM mean group scores after the study intervention of 10 hours over a 15-day period. The STA protocol group gained more with the study intervention than the PIP group, given identical parameters of attention, maturation, and environment. The investigators in this study suggest that increased frequency of intervention over frequencies commonly present in current EI programs may better facilitate maximal progress and realization of potential for infants with posture and movement dysfunction. The observed statistically significant increase in GMFM scores after implementation of the dynamic co-activation of trunk musculature protocol in the STA intervention group cautiously suggests a maximized return on investment of resources for the infants, therapists, and funding agencies. With return to routine EI therapeutic services and withdrawal of the study interventions during the 3-week postintervention period, both groups demonstrated a slight negative trend indicating the possible inability of routine ongoing EI therapeutic services to maintain or improve recent gains in gross motor skills. Implications from this study point to the need for continued research examining both the frequency and type of intervention critical for infants with posture and movement dysfunction, eg, comparisons between direct therapy and consultative service delivery models and intervention frequency.
Retention of Gains
The within-group mean GMFM scores from posttest to 3-week FU provide evidence that gains made from a short, intensive NDT-based STA protocol can be maintained for the short term. Although skills are maintained, continued specific sequential trunk activation intervention is likely needed to promote further progress.
The wide variance in both groups of GMFM change scores posttest to 3-week FU generates questions regarding the infants’ underlying body system impairments and subsequent functional gross motor limitations. Participants whose scores declined in the postintervention to 3-week FU period seemed to have motor limitations strongly influenced by sensory processing dysfunction. Although sensory testing was not conducted, numerous sensory defensive behaviors were observed during intervention. Future research should include discriminatory measures to differentiate infants with and without sensory processing dysfunction. Such identification of infants with sensory processing dysfunction may help clarify which infants will better retain gains made with the NDT-based STA protocol intervention.
In future research, the retention of gains should be assessed over a longer FU period than in the current study. Varying periods of intervention or no intervention is recommended to discover which schedule(s) yield maximal gains and retention effects for specific disabilities and impairments.
Instrument and Rater Reliability
The evaluative tool used in this study was validated for infants with posture and movement dysfunction (ie, CP) to measure change over time as a result of intervention. Studies reported earlier, ie, Goodman et al,6,9 Piper et al,7,8 Weindling et al,11 and Salokorpi et al12,13 used outcome measures that were standardized on typically developing populations. The use of appropriate outcome instruments with reported reliability and validity for specific populations and interrater reliability of examiners masked to group assignment and study intent are critical for addressing the question of intervention efficacy in specialized populations with posture and movement dysfunction.
Possible challenges to EI policy related to service delivery models and frequency of intervention are generated by this study. Scrutiny must be given to the national trend of using a generalized play approach delivered by early interventionists with therapist consultation for motor intervention services to infants with posture and movement dysfunction. The researchers of this study suggest that focused intervention specifically matched to identified impairments and delivered by a NDT-infant-trained therapist can produce a significantly higher level of motor skill improvement compared with nonfocused intervention delivered by a more generally trained interventionist when provided at the same increased frequency. A generalized play approach may have benefits in other areas, ie, cognition, social; however, this may not be true for motor skills.
The balance between using generalized interventionists and licensed professionals with subspecialty training in infant development and movement science within the EI service delivery model is in need of further evaluation. Continued research is essential to define the quantity of intervention, the specific intervention protocol, and the skills of the provider for optimal and cost-effective outcomes for infants with posture and movement dysfunction.
Four primary features of the study limiting the generalizability of results are (1) small sample size, low power, and purposive convenience sampling, (2) rater masked to group assignment but not to study intent, (3) outside routine EI therapeutic services tracked but not controlled, and (4) infant cognition not tested. The small sample size in this study was a result of the referral policies of the specific locale (eg, economics; Health Insurance Portability and Accountability Act) and the 44% to 50% attrition rate. The primary reason for attrition in the PIP group was that parents were interested in participating in the study only if their infants were in the STA treatment group. No measure directly assessed the infants’ cognitive level, although it is clinically assumed to influence the infants’ motivation and ability to learn. Future development of a motor-free cognitive tool for infants’ ages 4 to 12 months is needed. Infant cognitive abilities may then be used to more equitably stratify groups before randomization.
A short-duration, high-frequency NDT-based infant protocol focused on dynamic co-activation of trunk flexors and extensors and specifically sequenced trunk movements significantly improved gross motor function in infants with posture and movement dysfunction compared to a nonindividualized Parent-Infant-Play protocol that only indirectly addressed the trunk. These motor gains were maintained for 3 weeks. Providing attention through guided, enriched play activities and interaction with social support did not significantly improve infant motor performance during the same time period. The infants with posture and movement dysfunction made gains that seemed to be the result of the short-duration, high-frequency, sequential trunk activation interventions provided by pediatric therapists specializing in the NDT approach for infants.
The authors are grateful to Barry Chapman, MS, PT, for his role in testing infants, and to Mitzi Wiggin, MS, PT, for specific support recruiting families, providing the research site, and testing the infants. Special acknowledgment is given to Kristy Loper, BA, Child Life Specialist, for her coordination of the parent-infant play group. Dr. Ed Gracely, Dr. John Pezzullo, and Dr. Steve Allison generously assisted in the sample size write-up. The authors also wish to thank the infants and parents who participated in this study.
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NDT-Based Infant Sequenced Trunk Activation Treatment Protocol Within the NDT Problem-Solving Assessment and Intervention Planning
The STA treatment protocol used in the study was taught to NDT-trained pediatric therapists in a 3-week advanced specialization course for NDT-based infant treatment. Study intervention sessions occurred during treatment practicums, in the second and third weeks of the course. The course faculty supervised the course participant-therapists during the 10 one-hour treatment practicum sessions. The course curriculum consisted of didactic, practical, experiential, and problem solving activities totaling 103.75 contact hours.
Each individualized intervention plan was developed to meet the functional goals collaboratively established by the parents, course participant-therapists, and course faculty from infant and parent needs and concerns. The functional goals addressed transitional mobility skills (eg, rolling, prone to sitting, sitting to quadruped to sitting, quadruped to standing) within a variety of positions, as well as interaction skills with environment and caregiver. The functional goals were analyzed to identify the following essential posture and movement components†:
- Head orientation toward vertical
- Eyes horizontal
- Appropriate base of support for functional activity
- Trunk alignment over appropriate base of support
- Neutral pelvis
- Actively balanced trunk musculature with weight shift
- Trunk elongation on the weight-bearing side
Appropriate orienting of head and body parts to the support surface for maximal contact and proprioceptive sensory input.
The essential posture and movement components that were missing, delayed, or atypical for the identified functional goal were targeted. Dynamic control by the infant of the targeted posture and movement components was then facilitated, repeated, and embedded in the context of meaningful appropriate play activities.
When intervening with the infant during a transitional activity identified in the functional goal(s) and addressing the targeted missing, delayed, or atypical posture and movement components, the course participant-therapist followed a fluid sequence:
- Systems Review: Review both positive and negative effects of relevant systems on the specifically selected functional activity and adapt the intervention plan to capitalize or adjust for system impairment. Systems to be considered are: the auditory, visual, respiratory, cardiovascular, gastrointestinal, integumentary, nervous (state control, arousal), sensory, musculoskeletal, and neuromuscular systems.
- Engage: Build trust. Wait for the infant to actively participate in reciprocal interactions before touching the infant. The infant may actively participate by giving eye contact, vocalizing, or physically touching the therapist.
- Prepare: Address range of motion, level of alertness and arousal, and sufficient postural tone needed for the infant to activate the targeted posture and movement components.
- Align: Make physical and environmental adjustments to align body joints and body mass over an appropriate base of support for the targeted posture and movement components.
- Activate: With clear intention, elicit dynamic co-activation of flexors and extensors of the head and trunk musculature and facilitate weight shifts into the base of support. Weight shifts for dynamic trunk activation are facilitated in a specific sequence of planes of trunk movement: sagittal first, frontal second, and transverse last.
- Repetition: Provide multiple opportunities, within each intervention session, for repetitions of posture and movement components of selected functional goals within the context of an appropriate play or daily life activity. Physical assistance must be graded to allow infant to gradually achieve independent motor skills.
- Home repetition: Integrate selected, targeted posture and movement components into function at home. Use activities of daily living, such as, carrying, picking up, putting down, and diapering for multiple opportunities to strengthen, integrate, and generalize posture and movement components into functional activities in home environment.
The STA protocol intervention was applied specifically to the “activate” portion of each activity sequence. The STA protocol intervention is focused on facilitated dynamic co-activation of trunk flexors and extensors and specifically sequenced trunk movements during transition activities and consists of the following: (1) facilitation of dynamic co-activation of trunk flexors and extensors in the sagittal plane that is adequate to the demands of a specific functional activity, (2) facilitation of active weight shifts in the frontal plane to produce “elongation on the weight-bearing side,” while maintaining the appropriate dynamic co-activation of trunk flexors and extensors,16 and (3) facilitation of active functional trunk rotation, while maintaining dynamic co-activation of trunk flexors and extensors and active trunk elongation of the weight-bearing side, ie, transverse plane. Functional trunk rotation is integral to the development of equilibrium behaviors for variability in motor responses20 and higher level balance.16(p.41) Functional trunk rotation is facilitated as appropriate for the age of the infant and the specific functional skill within the chosen activity.
Each step in the STA protocol creates the base needed for the next step in the sequence. Intervention that incorporates the STA protocol produces dynamic trunk co-activation in sequenced trunk movements adequate for the demands of transitional activities. In an infant-led session, the individualized application of the protocol may seem different for each infant and within a session depending on the functional activity of interest to the infant.‡
Parent-Infant Playgroup Protocol
A licensed Child Life Specialists coordinated the PIP group that met for 10 one-hour sessions over a period of 15 days. A graduate psychology student, who was a mother of a child with CP, and an aerobics instructor who specialized in postpartum exercises, assisted the Child Life Specialist in the intervention activities for the parents and infants.
The parents delivered the enriched play activities, with guidance from the Child Life Specialist for 30 minutes at each of the 10 intervention sessions (Table 3). The play activities, selected from Gymboree, A Parent’s Guide to Baby Play,21 targeted various areas of development, such as: visual, tactile, auditory, social, cognitive, emotional, and communication.
The psychology graduate student planned and led the discussion sessions. The topics she included during the six 30-minute blocks were (1) importance of self care; (2) ways to feel empowered; (3) Elizabeth Kubeler-Ross’s stages of grieving, particularly in relation to their infant’s disability; (4) coping skills for managing an infant with a disability; and (5) sharing their “stories.”
The postpartum aerobic instructor led the parents in a comfortably paced, general body fitness routine that included their infants. Each session involved continuous activity for 30 minutes, during four of the 10 group sessions. The instructor demonstrated ways to pick-up and put down the infants with appropriate body mechanics to reduce the risk of back injury and to tone the abdominal muscles of the adult. She demonstrated ways to push the infant in the stroller to perform gentle body muscle stretching and strengthening activities. The instructor incorporated holding, lifting, and moving the infant for adult upper and lower body strengthening activities during play times.
*NDT-based STA protocol with clinical example is available by request to the first author.
†The category of effective and ineffective posture and movement function components is depicted in “The NDT Enablement Classification of Health and Disability,” Table 2.1, page 82, found in Neuro-Developmental Treatment Approach: Theoretical Foundations and Principles of Clinical Practice by Howle (2002).16
‡NDT-based STA protocol with clinical example is available by request to the first author.