Children with developmental coordination disorder walk cautiously and resist forward-falling perturbations better than typical, but do not improve with practice

Debelle, Heloise, Hollands, Mark, Foster, Richard, Wood, Greg ORCID: https://orcid.org/0000-0003-0851-7090, Maganaris, Constantinos and O'Brien, Thomas (2024) Children with developmental coordination disorder walk cautiously and resist forward-falling perturbations better than typical, but do not improve with practice. In: ESMAC 2024, 12-14 September 2024, Oslo, Norway.

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Abstract

Introduction: Children with developmental coordination disorder (DCD) fall more often than typically developing (TD) peers [1], causing injuries, activity avoidance, and social exclusion [2]. Interventions using repeated gait perturbations improve stability recovery and reduce fall rates for healthy [3] and impaired adults [4]. It is unknown how children with DCD respond to gait perturbations, whether they would benefit from such interventions, or whether any benefits would transfer to different directions of perturbations. Research Question: RQ1: Is there a difference in stability between TD and children with DCD following a single gait perturbation? RQ2: a) Do TD and children with DCD improve their stability recovery after repeated perturbations? b) Are training improvements transferable between directions of perturbations? Methods: Participants walked on an instrumented treadmill which imposed 10 Forward-Falling (FFs) and 10 Backward-Falling perturbations through right belt accelerations and decelerations, respectively (Figure 1.A). Kinetics and kinematics were captured for each trial. The margin of stability [5] (MOS; normalised to walking speed) was computed from three minutes of Normal walking, and for each recovery step following perturbations. To answer RQ1, MOS over FF01 was compared between Groups and Steps at the heel strikes just before the onset of belt acceleration (Pre), and the first and second recovery steps (Rec1 and Rec2, respectively). To answer RQ2, MOS was compared between Groups and Trials to test learning and transferability of the training benefits. Results: Participants’ characteristics are displayed in Figure 1.B. Children with DCD were more stable during normal walking than TD. Following FF01, the MOS of children with DCD reduced in Rec1 (mean difference to Normal: -4.5cm), but the destabilising effect was not detected until Rec2 for TD children, although the effect was larger (mean difference to Normal: -8.6cm) (Figure 1.C). The destabilising effect in Rec1 of children with DCD persisted in all trials: they did not improve their stability with repeated perturbations. In contrast, TD children improved their stability recovery and returned their MOS at Rec2 back to Normal level by FF10 (Figure 1.D).