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

Abstract

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.

Keywords:

• Capacity
• infancy
• motor delay
• performance
• sitting

Acknowledgments

We gratefully acknowledge the families who volunteered to participate in this study and the clinical trial assessors for their assistance in data collection.

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This project was supported by the Institute of Education Sciences, National Center for Special Education Research, Early Intervention and Early Learning in Special Education Award R324A150103; a Children’s Hospital Foundation Research Grant; a Virginia Commonwealth University Post-Doctoral Association Research Grant; and National Institutes of Child Health and Human Development K12 HD055929.

Notes on contributors

Kari S. Kretch

Kari S. Kretch, PT, DPT, PhD, is an Assistant Professor in the Division of Biokinesiology and Physical Therapy at the University of Southern California. Her research focuses on perceptual-motor skills and processes of developmental change in infants with typical and atypical motor development.

Natalie A. Koziol

Natalie A. Koziol, PhD, is a Research Assistant Professor for the Nebraska Academy for Methodology, Analytics & Psychometrics within the Nebraska Center for Research on Children, Youth, Families & Schools at the University of Nebraska-Lincoln. Her research focuses on the evaluation, improvement, and application of quantitative methods in the health and behavioral sciences.

Emily C. Marcinowski

Emily C. Marcinowski, PhD, is an Assistant Professor in the Department of Kinesiology at Louisiana State University. Her research interests primarily center on how motor skills and asymmetries affect the development of play, language, and cognition in early childhood, particularly in children younger than 2 years.

Lin-Ya Hsu

Lin-Ya Hsu, PT, PhD, is an Assistant Professor in the Division of Physical Therapy, Department of Rehabilitation Medicine at the University of Washington. Her research interests include early sensorimotor development and best-practice intervention and physical therapy management for infants and young children with neuromotor disorders and utilizing gaming technology for rehabilitation. She participates as a member of the national START-Play consortium.

Regina T. Harbourne

Regina T. Harbourne, PT, PhD, FAPTA, is Professor Emeritus in the Department of Physical Therapy, Rangos School of Health Sciences at Duquesne University, where she is the Director of the Infant Development Lab. She is the primary investigator for the START-Play project, and her research focuses on investigating the interaction of early movement skills and cognition, and the efficacy of intervention for infants and children with movement delays or dysfunction.

Michele A. Lobo

Michele A. Lobo, PT, PhD, is an Associate Professor in the Department of Physical Therapy at the University of Delaware, where she is the Co-Director of the Move to Learn Innovation Lab and is the Founder and Director of the Super Suits FUNctional Fashion & Wearable Technology Program. Her research focuses on understanding developmental processes to inform the development and evaluation of novel interventions and technologies for pediatric rehabilitation.

Sarah W. McCoy

Sarah W. McCoy, PT, PhD, was Professor Emeritus and former head of the Division of Physical Therapy in the Department of Rehabilitation Medicine at University of Washington. She fully retired in May 2023.

Sandra L. Willett

Sandra L. Willett, PT, PhD, is an Associate Professor and Board Certified Clinical Specialist in pediatric physical therapy at Colorado Mesa University in Grand Junction. She is a full-time faculty member with long-standing clinical expertise in early intervention, NICU and NICU follow-up practice settings. She is a member of the national START-Play consortium. Research interests include early motor development, parent-child interaction, and best-practice intervention/implementation strategies for infants and young children with or at-risk of motor and/or developmental delays.

Stacey C. Dusing

Stacey C. Dusing, PhD, PT, FAPTA, is the Sykes Family Chair in Pediatric Physical Therapy, Pediatric Health and Development and Associate Professor in the Division of Biokinesiology and Physical Therapy at the University of Southern California. Dr. Dusing is a board-certified Clinical Specialist in Pediatric Physical Therapy and the Director of the Motor Development Lab (MDL). Her primary research interests include understanding the influence of motor control on global development and efficacy of physical therapy interventions for infants. Specifically, she focuses on the relationship between postural control, reaching, mobility, and cognition in infants with typical development and at risk for disabilities, and interventions for infants born prematurely or with cerebral palsy.