Postural Stability in Children with Autism Spectrum Disorder

Abstract

Maintaining upright posture is a complex process involving multiple afferent systems. The aim of this study was to measure the postural stability of children with Autism Spectrum Disorder (ASD) compared with children with typical neurodevelopment and to measure the relative contributions of the visual, somatosensory, and vestibular afferent systems in each group. Eight boys with ASD and eight age-, race-, and gender-matched controls participated in this study using force platform technology with customized software to measure postural sway under conditions designed to eliminate or modify visual and somatosensory input. Children with ASD had significantly larger sway areas under all test conditions in which afferent input was modified. These results are consistent with a deficit in the integration of visual, vestibular, and somatosensory input to maintain postural orientation.

Attentional and sensory contributions to postural sway in children with autism spectrum disorder

“…The groups reacted differently to the removal of vision: for the range of the COP in the ML direction, the destabilizing effect of closing the eyes was larger for the ASD group than for controls. This finding is consistent with earlier studies [8,23], and suggests that individuals with ASD have greater reliance on visual input for the regulation of balance, making it more difficult to maintain balance with the eyes closed. A recent study [28] revealed unexpected and substantial superiority in visual motion perception in children with ASD, compared to controls.…”

“…Previous studies [8,23] have found decreased postural performance in ASD when the eyes are closed. Closing the eyes leads to a shift toward other sensory modalities to regulate balance, necessitating more attentiondemanding control of balance.…”

“…Relatedly, a review [29] found that individuals with ASD consistently outperform controls on visual search tasks; possibly mediated by 'over-focused attention'. We speculate that this superiority is reflected in a tighter coupling between visual channels that register changes in optic flow (as a result of postural sway) and the motor system responsible for maintaining balance [23]. This tighter coupling, in turn, becomes manifest as faster postural adjustments.…”

What can autism teach us about the role of sensorimotor systems in higher cognition? New clues from studies on language, action semantics, and abstract emotional concept processing

“…These speak of deficits such as in handwriting (Kushki, Chau, & Anagnostou, 2011) and (relatedly) fine-precision grip (David, Baranek, Wiesen, Miao, & Thorpe, 2012); in postural stability (Molloy, Dietrich, & Bhattacharya, 2003) and as documented in the studies above, gait (Esposito & Venuti, 2008;VernazzaMartin et al, 2005;Vilensky, Damasio, & Maurer, 1981); of akinesia, dyskinesia and bradykinesia (Damasio & Maurer,6 Motor symptoms are not the only symptoms that appear in the first year of life; we refer the interested reader to several other papers which point out early abnormalities in social orientation among other symptoms in the first year of life (Clifford & Dissanayake, 2008;Clifford et al, 2013;Clifford, Young, & Williamson, 2007;Dawson et al, 2004;Maestro, Muratori, Barbieri et al, 2001; 1978; Maurer & Damasio, 1982); and finally of hand dystonia and facial grimacing (Wing, 1981).…”

Postural Control Deficits in Autism Spectrum Disorder: The Role of Sensory Integration

“…This finding was attributed to a sensory integration impairment reflected in hypo-reactivity to visual sway-inducing information. In the proprioceptive domain, Molloy et al (2003) asked TD and ASD children to stand on a fixed surface and on foam with and without vision. They showed that children with ASD exhibited greater sway areas, with this effect increasing with task difficulty.…”