The development of gait and mobility: Form and function in infant locomotion

The development of locomotion can be described by its form (i.e., gait) and its function (i.e., mobility). Both aspects of locomotion improve with experience. Traditional treatises on infant locomotion focus on form by describing an orderly progression of postural and locomotor milestones en route to characteristic patterns of crawling and walking gait. We provide a traditional treatment of gait by describing developmental antecedents of and improvements in characteristic gait patterns, but we highlight important misconceptions inherent in the notion of "milestones". Most critically, we argue that the prevailing focus on gait and milestones fails to capture the true essence of locomotion-functional mobility to engage with the world. Thus, we also describe the development of mobility, including the use of mobility aids for support and propulsion. We illustrate how infants find individual solutions for mobility and how the ability to move cascades into other domains of development. Finally, we show how an integration of gait and mobility provides insights into the psychological processes that make locomotion functional. This article is categorized under: Psychology > Motor Skill and Performance Psychology > Development and Aging.

Practice and proficiency: Factors that facilitate infant walking skill

Infant walking skill improves with practice-crudely estimated by elapsed time since walk onset. However, despite the robust relation between elapsed time (months walking) and skill, practice is likely constrained and facilitated by infants' home environments, sociodemographic influences, and spontaneous activity. Individual pathways are tremendously diverse in the timing of walk onset and the trajectory of improvement, and presumably, in the amount and type of practice. So, what factors affect the development of walking skill? We examined the role of months walking, walk onset age, spontaneous locomotor activity, body dimensions, and environmental factors on the development of walking skill in two sociodemographically distinct samples (ns = 38 and 44) of 13-, 15-, and 19-month-old infants. Months walking best predicted how well infants walked, but environmental factors and spontaneous activity explained additional variance in walking skill. Specifically, less crowded homes, a larger percentage of time in spontaneous walking, and a smaller percentage of short walking bouts predicted more mature walking. Walk onset age differed by sample but did not affect walking skill. Findings indicate that elapsed time since walk onset remains a robust predictor of walking skill, but environmental factors and spontaneous activity also contribute to infants' practice, thereby affecting walking skill.

Exploratory analysis of a developmentally progressive modified ride-on car intervention for young children with Down syndrome

BACKGROUND

Children with Down syndrome (DS) may have limited opportunities to engage in self-directed mobility and play due to motor delays. A recent modified ride-on car innovation is the sit-to-stand (STS) model, which incorporates functional standing and walking training with the experience of powered mobility.

AIMS

This study aimed to: (1) describe total dosage and daily usage of three modified ride-on car modes (seated, standing, and power-push) by young children with DS; (2) examine the ability of young children with DS to independently activate the modified ride-on car in seated and standing modes; (3) describe the age of onset of selected motor milestones of the sample in comparison to DS norms.

MATERIALS AND METHODS

Eight young children with DS (8.6 ± 2.0 months) used three modes of the modified ride-on car over a 9-month intervention.

RESULTS

All eight children independently activated the modified ride-on car in seated and standing modes. Most motor milestones were achieved earlier in this sample than expected for DS norms, including the onset of independent walking.

CONCLUSIONS AND IMPLICATIONS

The developmentally progressive nature of the intervention and high dosage may have been instrumental in encouraging the onset of independent activation and earlier motor milestones.IMPLICATIONS FOR REHABILITATIONYoung children with Down syndrome were able to achieve independent activation in seated and standing modified ride-on cars.Developmentally progressive modified ride-on car interventions may facilitate motor skill development, but future work utilizing a randomized control group is needed to examine the potential motor developmental benefits of the STS model and power-push mode.The developmentally progressive nature of the intervention may have been instrumental in encouraging the onset of independent switch activation in both seated and standing modes, as well as the high dosage and adherence rates compared to previous studies.

Real World Tracking of Modified Ride-On Car Usage in Young Children With Disabilities

BACKGROUND

Go Baby Go is a community program that provides modified ride-on cars to young children with disabilities.

AIMS

(1) To describe the real world modified ride-on car usage of young children with disabilities; (2) To compare subjectively reported modified ride-on car usage recorded by parents with objectively reported usage based on electronic tracking data.

METHODS

14 young children (1-3 years old) with disabilities used a modified ride-on car for three months.

RESULTS

On average, parent-reported activity log data indicated that children used the modified ride-on car for 17.8 minutes per session (SD = 9.9) and 195.1 total minutes (SD = 234.8) over three months. Objective tracking data indicated 16.5 minutes per session (SD = 8.6) and 171.4 total minutes (SD = 206.1) over three months. No significant difference of modified ride-on car usage was found between parent-reported activity log data and objective tracking; yet, the mean absolute difference between tracking methods was 96 minutes (SD = 8.6) and suggests over- or under-reporting of families. Children used the modified ride-on car more in the first half compared to the second half of the three-month period (p < .05).

CONCLUSIONS

This study may inform future research studies and local chapters of the Go Baby Go community program.