Do "Shufflebottoms" bottom shuffle?

Development (of Walking): 15 Suggestions

Although a fundamental goal of developmental science is to identify general processes of change, developmental scientists rarely generalize beyond their specific content domains. As a first step toward a more unified approach to development, we offer 15 suggestions gleaned from a century of research on infant walking. These suggestions collectively address the multi-leveled nature of change processes, cascades of real-time and developmental events, the diversity of developmental trajectories, inter- and intraindividual variability, starting and ending points of development, the natural input for learning, and the roles of body, environment, and sociocultural context. We argue that these 15 suggestions are not limited to motor development, and we encourage researchers to consider them within their own areas of research.

A new twist on old ideas: how sitting reorients crawlers

Traditionally, crawling and sitting are considered distinct motor behaviors with different postures and functions. Ten- to 12-month-old infants were observed in the laboratory or in their homes while being coaxed to crawl continuously over long, straight walkways (Study 1; N = 20) and during spontaneous crawling during free play (Study 2; N = 20). In every context, infants stopped crawling to sit 3-6 times per minute. Transitions from crawling to sitting frequently turned infants' bodies away from the direction of heading; subsequent transitions back to crawling were offset by as much as 180° from the original direction of heading. Apparently, body reorientations result from the biomechanics of transitioning between crawling and sitting. Findings indicate that sustained, linear crawling is likely an epiphenomenon of how gait is studied in standard paradigms. Postural transitions between crawling and sitting are ubiquitous and can represent a functional unit of action. These transitions and the accompanying body reorientations likely have cascading effects for infants' exploration, visual perception, and spatial cognition.

Age for onset of walking and prewalking strategies

BACKGROUND

Age for onset of independent walking (AOW) is frequently used as an indicator of the progress of motor development in early life. Yet there is considerable uncertainty in the research literature about the age we should expect children to walk independently, and also whether prewalking strategies are of importance for this milestone. In clinical practice we commonly experience that children start walking at later ages than the standards presented in the Alberta Infant Motor Scale (AIMS), the most frequently used standardized instrument of gross motor development in Norway.

AIMS

To investigate the normal distribution of AOW among Norwegian children, which prewalking locomotor strategies (PLS) children used before AOW, and if children who crawled on hands and knees started to walk earlier than children with other strategies.

DESIGN AND METHODS

This cross-sectional study was based on parental self reports from two data sources, i.e. the Norwegian Mother and Child Cohort Study (MoBa, n = 47,515), and project specific regionally collected data (n = 636).

RESULTS

Half of the Norwegian children had started to walk at 13 months (median). Twenty-five percent walked at 12 months and 75% of the children walked at 14 months. Mean AOW, claiming at least 5 independent steps, was 13.1 (1.91)months. Children who used crawling on hands and knees (84.5%) as PLS started to walk unaided 0.9 months earlier (95% CI = 0.32-1.49, p < 0.05) than bottom shufflers (7.1%).

CONCLUSION

Norwegian children start to walk considerably later than standards reported in AIMS. Crawling on hands and knees is associated with an earlier onset of walking.

WEIRD walking: cross-cultural research on motor development

Motor development - traditionally studied in WEIRD populations - falls victim to assumptions of universality similar to other domains described by Henrich et al. However, cross-cultural research illustrates the extraordinary diversity that is normal in motor skill acquisition. Indeed, motor development provides an important domain for evaluating cultural challenges to a general behavioral science.