Sitting Capacity and Performance in Infants with Typical Development and Infants with Motor Delay.

AIMS: Infants with neuromotor disorders demonstrate delays in sitting skills (decreased capacity) and are less likely to maintain independent sitting during play than their peers with typical development (decreased performance). This study aimed to quantify developmental trajectories of sitting capacity and sitting performance in infants with typical development and infants with significant motor delay and to assess whether the relationship between capacity and performance differs between the groups. METHODS: Typically developing infants (n = 35) and infants with significant motor delay (n = 31) were assessed longitudinally over a year following early sitting readiness. The Gross Motor Function Measure (GMFM) Sitting Dimension was used to assess sitting capacity, and a 5-min free play observation was used to assess sitting performance. RESULTS: Both capacity and performance increased at a faster rate initially, with more deceleration across time, in infants with typical development compared to infants with motor delay. At lower GMFM scores, changes in GMFM sitting were associated with larger changes in independent sitting for infants with typical development, and the association between GMFM sitting and independent sitting varied more across GMFM scores for typically developing infants. CONCLUSIONS: Intervention and assessment for infants with motor delay should target both sitting capacity and sitting performance.

Early Mobility and Crawling: Beliefs and Practices of Pediatric Physical Therapists in the United States.

PURPOSE: To characterize beliefs of pediatric physical therapists (PTs) in the United States regarding the role of crawling in infant development and clinical practice. METHODS: Pediatric PTs reported their beliefs about early mobility and crawling, clinical approaches related to early mobility and crawling, and agreement with the removal of crawling from the Centers for Disease Control and Prevention (CDC)'s updated developmental milestone checklists in an online survey. Analyses examined associations between information sources and beliefs, between beliefs and clinical approaches, and between beliefs and CDC update opinions. RESULTS: Most participants believed that crawling was important (92%) and linked to a variety of positive developmental outcomes (71%-99%) and disagreed with its removal from the CDC checklists (79%). Beliefs were linked with clinical approaches focused on promoting crawling and discouraging other forms of mobility. CONCLUSIONS: Further research is needed to determine whether pediatric PTs' beliefs and clinical practices are supported by evidence.

Opportunities for learning and social interaction in infant sitting: Effects of sitting support, sitting skill, and gross motor delay.

The development of independent sitting changes everyday opportunities for learning and has cascading effects on cognitive and language development. Prior to independent sitting, infants experience the sitting position with physical support from caregivers. Why does supported sitting not provide the same input for learning that is experienced in independent sitting? This question is especially relevant for infants with gross motor delay, who require support in sitting for many months after typically developing infants sit independently. We observed infants with typical development (n = 34, ages 4-7 months) and infants with gross motor delay (n = 128, ages 7-16 months) in early stages of sitting development, and their caregivers, in a dyadic play observation. We predicted that infants who required caregiver support for sitting would spend more time facing away from the caregiver and less time contacting objects than infants who could sit independently. We also predicted that caregivers of supported sitters would spend less time contacting objects because their hands would be full supporting their infants. Our first two hypotheses were confirmed; however, caregivers spent surprisingly little time using both hands to provide support, and caregivers of supported sitters spent more time contacting objects than caregivers of independent sitters. Similar patterns were seen in the group of typically developing infants and the infants with motor delay. Our findings suggest that independent sitting and supported sitting provide qualitatively distinct experiences with different implications for social interaction and learning opportunities. HIGHLIGHTS: During seated free play, supported sitters spent more time facing away from their caregivers and less time handling objects than independent sitters. Caregivers who spent more time supporting infants with both hands spent less time handling objects; however, caregivers mostly supported infants with one or no hands. A continuous measure of sitting skill did not uniquely contribute to these behaviors beyond the effect of binary sitting support (supported vs. independent sitter). The pattern of results was similar for typically developing infants and infants with gross motor delay, despite differences in age.

START-Play Physical Therapy Intervention Indirectly Impacts Cognition Through Changes in Early Motor-Based Problem-Solving Skills.

PURPOSE: This study tested whether the Sitting Together and Reaching to Play (START-Play) physical therapy intervention indirectly impacts cognition through changes in perceptual-motor skills in infants with motor delays. METHODS: Participants were 50 infants with motor delays randomly assigned to START-Play plus Usual Care Early Intervention (UC-EI) or UC-EI only. Infants' perceptual-motor and cognitive skills were assessed at baseline and 1.5, 3, 6, and 12 months post-baseline. RESULTS: Short-term changes in sitting, fine motor skills, and motor-based problem-solving, but not reaching, predicted long-term changes in cognition. START-Play indirectly impacted cognition through motor-based problem-solving but not sitting, reaching, or fine motor skills. CONCLUSIONS: This study provided preliminary evidence that early physical therapy interventions that blend activities across developmental domains and are supported by an enriched social context can place infants on more optimal developmental trajectories.

Infant posture and caregiver-provided cognitive opportunities in typically developing infants and infants with motor delay.

Infants' developing motor skills-including mastery of new postures such as sitting and standing-affect opportunities for learning that facilitate cognitive development. But how infant posture affects caregiver behavior is largely unexplored. Moreover, we know little about effects of posture on learning opportunities in infants with motor delay. This study asked how infants with typical development and infants with significant motor delay use various postures during play, and whether posture is related in real time to caregiver-provided cognitive learning opportunities. Infants were videotaped five times over the course of a year in a free play session with a caregiver, starting when they demonstrated initial sitting skills. Posture and cognitive opportunities were coded moment-by-moment to assess duration and temporal overlap. We found that infants with typical development and infants with motor delay displayed similar use of postures initially, but infants with typical development demonstrated more mature postures over time. We also found that for both groups of infants, caregivers were most likely to provide cognitive opportunities when infants were sitting independently, and least likely when infants were supine. Our findings highlight the importance of upright sitting in typical and atypical infant development and suggest potential areas of intervention for infants with motor delay.

Effect of the START-Play Physical Therapy Intervention on Cognitive Skills Depends on Caregiver-Provided Learning Opportunities.

AIMS: This study evaluated whether caregiver-provided learning opportunities moderated the effect of START-Play physical therapy intervention on the cognitive skills of young children with neuromotor delays, and whether START-Play impacted caregiver-provided learning opportunities over time. METHODS: One hundred and twelve children with neuromotor delays (7-16 months) participated in a multisite randomized clinical trial evaluating the efficacy of START-Play. Children were assessed at baseline and 3 (post intervention), 6, and 12 months post baseline. Cognition was scored from the Bayley Scales of Infant & Toddler Development, Third Edition, cognitive scale. The proportion of time caregivers spent providing learning opportunities was coded from a 5-minute caregiver-child free play interaction. RESULTS: Baseline caregiver-provided learning opportunities moderated the 3- and 12-month effects of START-Play on cognition. Cognitive gains due to START-Play were more pronounced for children whose caregivers provided more learning opportunities. START-Play did not impact caregiver-provided learning opportunities over time. CONCLUSIONS: START-Play may have a lasting effect on children's cognition, but this effect is contingent on caregivers providing their child with ample opportunities to practice cognitive skills. Strategies for improving caregivers' uptake and transfer of START-Play principles to their daily routines should be evaluated. TRIAL REGISTRATION: ClinicalTrials.gov NCT02593825.

"Learn the Signs. Act Early.": Updates and Implications for Physical Therapists.

PURPOSE: In early 2022, the Centers for Disease Control and Prevention (CDC) updated their developmental surveillance milestone checklists. The purpose of this article is to clarify and interpret the updates from a physical therapist perspective and to discuss implications of the new milestones for physical therapists. SUMMARY OF KEY POINTS: The CDC's updated checklists provide clear, consistent, easy to use, and evidence-based developmental milestones to prompt discussion with families. The new checklists do not represent a lowering of standards and will likely increase, not decrease, referrals for screening, evaluation, and services. Crawling has been removed from the milestone checklists, as the current evidence suggests that crawling is highly variable and not essential for development. CONCLUSIONS AND RECOMMENDATIONS FOR CLINICAL PRACTICE: The updated milestone checklists will facilitate bringing vital services to children who need them. Physical therapists should support our primary care colleagues in implementing this useful program.

Object Permanence and the Relationship to Sitting Development in Infants With Motor Delays.

PURPOSE: This study examines object permanence development in infants with motor delays (MD) compared with infants with typical development (TD) and in relation to sitting skill. METHODS: Fifty-six infants with MD (mean age = 10 months) and 36 with TD (mean age = 5.7 months) were assessed at baseline and then at 1.5, 3, and 6 months postbaseline. A scale was developed to measure object permanence (Object Permanence Scale [OPS]), and the Gross Motor Function Measure sitting subsection (GMFM-SS), and the Bayley Scales of Infant and Toddler Development, 3rd Edition (Bayley-III) were administered. RESULTS: Interrater reliability of the OPS was excellent and correlation between the OPS and Bayley-III cognitive scores was moderately positive. Compared with TD, infants with MD were delayed in development of object permanence but demonstrated increased understanding over time and as sitting skills improved. CONCLUSION: In children with MD, object permanence, as quantified by the OPS, emerges in conjunction with sitting skill.

Developing a fidelity measure of early intervention programs for children with neuromotor disorders.

AIM: To describe the development of an intervention-specific fidelity measure and its utilization and to determine whether the newly developed Sitting Together and Reaching to Play (START-Play) intervention was implemented as intended. Also, to quantify differences between START-Play and usual early intervention (uEI) services. METHOD: A fidelity measure for the START-Play intervention was developed for children with neuromotor disorders by: (1) identifying key intervention components, (2) establishing a measurement coding system, and (3) testing the reliability of instrument scores. After establishing acceptable interrater reliability, 103 intervention videos from the START-Play randomized controlled trial were coded and compared between the START-Play and uEI groups to measure five dimensions of START-Play fidelity, including adherence, dosage, quality of intervention, participant responsiveness, and program differentiation. RESULTS: Fifteen fidelity variables out of 17 had good to excellent interrater reliability evidence with intraclass correlation coefficients (ICCs) ranging from 0.77 to 0.95. The START-Play therapists met the criteria for acceptable fidelity of the intervention (rates of START-Play key component use ≥0.8; quality ratings ≥3 [on a scale of 1-4]). The START-Play and uEI groups differed significantly in rates of START-Play key component use and quality ratings. INTERPRETATION: The START-Play fidelity measure successfully quantified key components of the START-Play intervention, serving to differentiate START-Play from uEI.

Early motor skills predict the developmental trajectory of problem solving in young children with motor delays.

INTRODUCTION: The purpose of this study was to quantify the relationship between early motor skills, such as sitting, and the development of problem-solving skills in children with motor delays. METHODS: Motor (Gross Motor Function Measure) and problem-solving (Assessment of Problem-Solving in Play) skills of 134 children 7-16 months adjusted age at baseline with motor delay were assessed up to 5 times over 12 months. Participants were divided into two groups: mild and significant motor delay. RESULTS: Motor and problem-solving scores had large (r's = 0.53-0.67) and statistically significant (p's > .01) correlations at all visits. Baseline motor skills predicted baseline and change in problem solving over time. The associations between motor and problem-solving skills were moderated by level of motor delay, with children with significant motor delay generally having stronger associations compared to those with mild motor delay. CONCLUSIONS: These findings suggest that overall baseline motor skills are predictive of current and future development of problem-solving skills and that children with significant motor delay have a stronger and more stable association between motor and problem-solving skills over time. This highlights that children with motor delays are at risk for secondary delays in problem solving, and this risk increases as degree of motor delay increases.

Measuring Early Problem-Solving in Young Children with Motor Delays: A Validation Study.

AIM: There is a lack of evidence-based tools for measuring problem-solving in young children with motor delays. The purpose of this study was to evaluate the construct validity and responsiveness of the Assessment of Problem-Solving in Play. METHODS: 125 young children (10.72, SD 2.62 months) with mild, moderate, and severe motor delays were assessed with the Bayley Scales of Infant and Toddler Development, Third Edition Cognitive Scale and the Assessment of Problem-Solving in Play up to 4 times over 12 months. The baseline and change over time assessment scores were compared. RESULTS: The Assessment of Problem-Solving in Play was strongly, positively correlated with the Bayley Scales of Infant and Toddler Development, Third Edition Cognitive Scale raw scores at baseline (r=.83, p<.001) and for changes in scores across time (r=.64, p<.001). On average, participants demonstrated positive change in problem-solving scores across time. Participants with severe motor delay scored lower at baseline and changed less as compared to other participants. CONCLUSIONS: Results provide evidence for the construct validity and responsiveness of the Assessment of Problem-Solving in Play scores in quantifying problem-solving in young children with motor delays 7-27 months of age.

A Novel Means-End Problem-Solving Assessment Tool for Early Intervention: Evaluation of Validity, Reliability, and Sensitivity.

PURPOSE: To evaluate validity, reliability, and sensitivity of the novel Means-End Problem-Solving Assessment Tool (MEPSAT). METHODS: Children with typical development and those with motor delay were assessed throughout the first 2 years of life using the MEPSAT. MEPSAT scores were validated against the cognitive and motor subscales of the Bayley Scales of Development. Intra- and interrater reliability, developmental trends, and differences among groups were evaluated. RESULTS: Changes in MEPSAT scores positively related to changes in Bayley scores across time for both groups of children. Strong intra- and interrater reliability was observed for MEPSAT scoring across all children. The MEPSAT was sensitive to identify change across time and differences in problem-solving among children with varying levels of motor delay. CONCLUSIONS: The MEPSAT is supported by validity and reliability evidence and is a simple tool for screening early problem-solving delays and evaluating change across time in children with a range of developmental abilities. What this adds to the evidence: The novel MEPSAT is supported by validity and reliability evidence. It is sensitive to detect problem-solving differences among young children with varying motor ability and to capture changes in problem-solving across time. It requires minimal equipment and time to administer and score and, thus, is a promising tool for clinicians to screen for early problem-solving delays or to track intervention progress in young children with or at risk for problem-solving delays.

Sit Still and Pay Attention! Trunk Movement and Attentional Resources in Infants with Typical and Delayed Development.

AIMS: (1) examine infant movement during an early posture (sitting) utilizing a novel video assessment technique; and (2) document the differences between infants with typical development (TD), premature infants with motor delay, and infants with cerebral palsy (CP) during focused and nonfocused attention (NFA). METHODS: Infants were tested when they began to sit independently. We utilized Eulerian Video Magnification (EVM) to accentuate small trunk and pelvic movements for visual coding from video taken during a natural play task with and without focused attention (FA). RESULTS: Trunk/pelvic movement varied as a function of both motor skill and attention. Infants with TD and CP made fewer trunk movements during periods of FA than NFA. Preterm infants exhibited more trunk/pelvic movement than the other groups and their movement did not differ based on attention type. CONCLUSIONS: The EVM technique allowed for replicable coding of real-time "hidden" motor adjustments from video. The capacity to minimize extraneous movements in infants, or "sitting still" may allow greater attention to the task at hand, similar to older children and adults. Premature infants' excessive trunk/pelvic movement that did not adapt to task requirements could, in the long term, impact tasks requiring attentional resources.

Infant sitting postural control appears robust across changes in surface context.

AIM OF THE STUDY: Independent sitting requires the control of the involved body segments over the base of support using information obtained from the three sensory systems (visual, vestibular, and somatosensory). The contribution of somatosensory information in infant sitting has not been explored. To address this gap, we altered the context of the sitting support surface and examined the infants' immediate postural responses. MATERIALS AND METHODS: Ten 7-month-old typically developing infants sat on compliant and firm surfaces in one session. Spatial, frequency, and temporal measures of postural control were obtained using center of pressure data. Results Our results suggest that infants' postural sway is not immediately affected by the different types of foam surface while sitting. CONCLUSIONS: It seems that mature sitter infants are able to adapt to different environmental constraints by disregarding the distorted somatosensory information from the support surface and relying more on their remaining senses (visual and vestibular) to control their sitting posture.

Neurorehabilitation Strategies Focusing on Ankle Control Improve Mobility and Posture in Persons With Multiple Sclerosis.

BACKGROUND AND PURPOSE: The neuromuscular impairments seen in the ankle plantarflexors have been identified as a primary factor that limits the mobility and standing postural balance of individuals with multiple sclerosis (MS). However, few efforts have been made to find effective treatment strategies that will improve the ankle plantarflexor control. Our objective was to determine whether an intensive 14-week neurorehabilitation protocol has the potential to improve the ankle plantarflexor control of individuals with MS. The secondary objectives were to determine whether the protocol would also improve postural control, plantarflexion strength, and mobility. METHODS: Fifteen individuals with MS participated in a 14-week neurorehabilitation protocol, and 20 healthy adults served as a comparison group. The primary measure was the amount of variability in the submaximal steady-state isometric torque, which assessed plantarflexor control. Secondary measures were the Sensory Organization Test composite score, maximum plantarflexion torque, and the spatiotemporal gait kinematics. RESULTS: There was less variability in the plantarflexion torques after the neurorehabilitation protocol (preintervention, 4.15% ± 0.5%; postintervention, 2.27% ± 0.3%). In addition, there were less postural sway (preintervention, 51.87 ± 0.2 points; postintervention, 67.8 ± 0.5 points), greater plantarflexion strength (preintervention, 0.46 ± 0.04 Nm/kg; postintervention, 0.57 ± 0.05 Nm/kg), and faster walking speeds (preferred preintervention, 0.71 ± 0.05 m/s; preferred postintervention, 0.81 ± 0.05 m/s; fast-as-possible preintervention, 0.95 ± 0.06 m/s; postintervention, 1.11 ± 0.07 m/s). All of the outcome variables matched or trended toward those seen in the controls. DISCUSSION AND CONCLUSIONS: The outcomes of this exploratory study suggest that the neurorehabilitation protocol employed in this investigation has the potential to promote clinically relevant improvements in the ankle plantarflexor control, standing postural balance, ankle plantarflexion strength, and the mobility of individuals with MS. Video abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A110).

Sitting and looking: a comparison of stability and visual exploration in infants with typical development and infants with motor delay.

This longitudinal study focused on the interaction of developing sitting postural control with look time, which served as a measure for cognitive processing. Twenty-eight typically developing infants and 16 infants with motor delays were evaluated using center-of-pressure measures to assess stability of sitting postural control and videography to assess look time at objects, at three progressive stages of sitting development. Results indicated that look time decreased significantly (p < .001) in conjunction with a significant increase in postural stability (p < .001) in both groups as sitting progressed to independence. Infants with motor delays showed significantly longer looks when compared to typical infants (p = .02) at the middle stage of sitting. We conclude that developmental changes in look time are related to changes in sitting postural control, and infants with motor delay may have greater difficulty looking during emerging postural control skills in sitting. Early interventionists may use look time as an indicator of sitting effort and cognitive processing during assessment and program planning.

Focused attention as a new sitter: How do infants balance it all?

This study investigated the impact of postural control on infants' Focused Attention (FA). Study 1 examined whether and how sitting independently versus with support impacted 6- to 8-month-old infants' ability to focus attention during object exploration. FA measures did not depend on support condition. However, sitting experience was significantly negatively correlated with FA measures in the supported condition, suggesting that infants with more sitting experience performed fewer exploratory movements, possibly due to faster information processing ability compared to infants with less sitting experience. These unexpected findings prompted an exploration of more subtle looking behaviors during FA in Study 2-a case study of three infants who wore a head-mounted eye-tracker during an FA task. The ability to rapidly shift visual attention was key to gathering environmental information useful for problem solving-an interpretation that is supported by prior findings of the relationship between fast looks and faster information processing.

The impact of severity of motor delay, timing of task mastery, and START-play intervention on the development of means-end problem solving in young children.

BACKGROUND: Children with motor delays are at increased risk for delayed means-end problem-solving (MEPS) performance. OBJECTIVES: To evaluate children with motor delays: 1) the impact of motor delay severity and MEPS mastery timing on developmental trajectories of MEPS; and 2) the effectiveness of Sitting Together And Reaching To Play (START-Play) intervention for improving MEPS. METHODS: This represents a secondary analysis from a multi-site randomized controlled trial, with blinded assessors and prospective registration. Children with mild or significant motor delays (n = 112, mean age=10.80, SD=2.59 months at baseline) were randomly assigned to START-Play or usual care early intervention (UC-EI) and assessed at five visits across one year using the Means-End Problem-Solving Assessment Tool that included three 30-second MEPS trials per visit. Task mastery occurred at the first visit the child achieved the highest level of performance in at least two of the three trials. Multilevel analyses evaluated trajectories of MEPS outcomes dependent upon the timing of MEPS mastery, motor delay severity, and intervention group. RESULTS: At baseline, children with mild motor delays demonstrated better MEPS than children with significant delays, but this difference was only observed for children who achieved mastery late. Children with significant delays demonstrated greater improvements in MEPS in the post-intervention phase compared to children with mild delays. No MEPS differences were found between START-Play and UC-EI. CONCLUSION: Motor delay severity and timing of task mastery impacted MEPS trajectories, whereas START-Play intervention did not impact MEPS for children with motor delays. CLINICAL TRIALS REGISTRY IDENTIFIER: NCT02593825 (https://clinicaltrials.gov/ct2/show/NCT02593825).

Sitting postural control in infants with typical development, motor delay, or cerebral palsy.

PURPOSE: To determine whether infants born full-term, infants born preterm with motor delays, and infants born preterm who have a diagnosis of cerebral palsy (CP) differed in postural control at the emergence of early sitting. METHODS: Thirty infants born at term who were developing typically, 6 infants born preterm who were later diagnosed with CP, and 5 infants born preterm who were delayed in motor development participated in this study. Center-of-pressure data from unsupported sitting were recorded and analyzed using measures of both amount and temporal organization of center-of-pressure variability. RESULTS: Infants born full-term, infants born preterm with motor delays, and infants born preterm who have a diagnosis of CP exhibited dissimilar movement-control strategies at the onset of sitting. CONCLUSIONS: The present findings may be helpful in directing and testing intervention protocols for infants born preterm.

The SIT-PT Trial Protocol: A Dose-Matched Randomized Clinical Trial Comparing 2 Physical Therapist Interventions for Infants and Toddlers With Cerebral Palsy.

OBJECTIVE: Although early intervention for infants at risk for cerebral palsy is routinely recommended, the content of intervention is poorly described, varies widely, and has mixed supporting evidence. The purpose of this study was to compare efficacy of 2 interventions grounded in differing domains of the International Classification of Functioning, Disability and Health on developmental outcomes of infants with or at high risk of cerebral palsy. METHODS: Infants who meet inclusion criteria will be randomized into either Sitting Together and Reaching To Play or Movement, Orientation, Repetition, Exercise Physical Therapy groups. Both groups will receive intervention twice weekly for 3 months and follow-up at 3, 6, 9, and 12 months from baseline. The primary objectives compare changes over time and between groups in sitting, gross motor, and cognitive development. The setting is the infant's home unless the caregiver requests otherwise. One hundred and fifty infants between 8 and 24 months of age will be enrolled in 3 geographically, racially, and ethnically diverse sites: Los Angeles, California; Omaha, Nebraska; and Seattle, Washington. Enrolled infants will demonstrate motor delays, emerging sitting skills, and signs of neurologic impairment. Sitting Together and Reaching To Play targets activities including sitting, reaching, and motor-based problem solving to improve global development. In contrast, Movement, Orientation, Repetition, Exercise Physical Therapy focuses on strengthening and musculoskeletal alignment while encouraging repeated movement practice. Outcome measures include the Gross Motor Function Measure, Bayley Scales of Infant Development-IV, Assessment of Problem Solving in Play, and a Parent Child Interaction assessment. Enrolled children will maintain usual intervention services due to ethical concerns with intervention withdrawal. IMPACT: This will be the first study, to our knowledge, comparing efficacy of early physical therapy with dose-matched interventions and well-defined key principles. The outcomes will inform selection of key principle of intervention in this population.