Children With Developmental Coordination Disorder Exhibit Greater Stepping Error Despite Similar Gaze Patterns and State Anxiety Levels to Their Typically Developing Peers

Abstract

This study examined stepping accuracy, gaze behavior, and state-anxiety in children with (N = 21, age M = 10.81, SD = 1.89) and without (N = 18, age M = 11.39, SD = 2.06) developmental coordination disorder (DCD) during an adaptive locomotion task. Participants walked at a self-selected pace along a pathway, placing their foot into a raised rectangular floor-based target box followed by either no obstacles, one obstacle, or two obstacles. Stepping kinematics and accuracy were determined using three-dimensional motion capture, whilst gaze was determined using mobile eyetracking equipment. The children with DCD displayed greater foot placement error and variability when placing their foot within the target box and were more likely to make contact with its edges than their typically developing (TD) peers. The DCD group also displayed greater variability in the length and width of their steps in the approach to the target box. No differences were observed between groups in any of the gaze variables measured, in mediolateral velocity of the center of mass during the swing phase into the target box, or in the levels of self-reported state-anxiety experienced prior to facing each task. We therefore provide the first quantifiable evidence that deficits to foot placement accuracy and precision may be partially responsible for the increased incidence of trips and falls in DCD, and that these deficits are likely to occur independently from gaze behavior and state-anxiety.

Children With Developmental Coordination Disorder Show Altered Visuomotor Control During Stair Negotiation Associated With Heightened State Anxiety

“…Evidently, anxiety is a critical factor that must be considered to fully understand the mechanisms underpinning the visuomotor control strategies of children with DCD during stair negotiation. Though we have recently shown that children with DCD do not experience heightened anxiety during over ground targeted stepping tasks (Parr et al, 2020), stair negotiation is likely to place greater demands on dynamic stability and increase the risk of significant injury in the event of a fall and may, therefore, be more likely to instill a fear response.…”

“…Consequently, children with DCD may formulate inaccurate stepping actions due to the suboptimal use of gaze to extract relevant and timely information from the environment, and the inability to predict the consequences of the ensuing movement (Wilson et al, 2013). Though our recent findings suggest that stepping inaccuracies in children with DCD may also occur despite typical looking behavior (Parr et al, 2020), it is important to determine whether the visuomotor control strategies adopted by children with DCD may be contributing to difficulties with stair negotiation.…”

“…Children with DCD also adopt a safer walking strategy during treadmill walking (Deconinck et al, 2006) and display a reduced ability to control their momentum when crossing obstacles (Deconinck et al, 2010), both of which have been attributed to a deficit to dynamic balance control. Given that children with DCD are also less accurate when tasked with precise stepping actions (Parr et al, 2020), it is unsurprising that they trip and bump into things more frequently than their TD peers (Kirby et al, 2011;Cleaton et al, 2020).…”

“…Indeed, to recover from a loss of balance when going down the stairs, individuals must rapidly reposition their limbs whilst controlling for downwards momentum (McFadyen and Winter, 1988;Novak and Brouwer, 2011). Difficulties negotiating stairs in children with DCD may, therefore, be associated with difficulties making accurate and consistent stepping actions (Rosengren et al, 2009;Parr et al, 2020) and deficits to dynamic stability (Deconinck et al, 2006(Deconinck et al, , 2010.…”

“…We hypothesized that the children with DCD would report heightened state anxiety and adopt a more cautious stair negotiation strategy, reflected by greater handrail use, slower walk times and more proximal gaze fixations to guide ongoing stepping commands in order to maintain stability. We also hypothesized that children with DCD would display smaller and more variable step-edge clearances compared to TD children, given their association with stair-related falls and recent evidence of decreased stepping accuracy and precision in children with DCD (Parr et al, 2020).…”