The role of visual stimuli on standing posture in children with bilateral cerebral palsy

Abstract

BackgroundIn children with bilateral cerebral palsy (CP) maintaining a standing position can be difficult. The fundamental motor task of standing independently is achieved by an interaction between the visual, somatosensory, and vestibular systems. In CP, the motor disorders are commonly accompanied by sensory and perceptual disturbances. Our aims were to examine the influence of visual stimuli on standing posture in relation to standing ability.MethodsThree dimensional motion analysis with surface electromyography was recorded to describe body position, body movement, and muscle activity during three standing tasks: in a self-selected position, while blindfolded, and during an attention-demanding task. Participants were twenty-seven typically-developing (TD) children and 36 children with bilateral CP, of which 17 required support for standing (CP-SwS) and 19 stood without support (CP-SwoS).ResultsAll children with CP stood with a more flexed body position than the TD children, even more pronounced in the children in CP-SwS. While blindfolded, the CP-SwS group further flexed their hips and knees, and increased muscle activity in knee extensors. In contrast, the children in CP-SwoS maintained the same body position but increased calf muscle activity. During the attention-demanding task, the children in CP-SwoS stood with more still head and knee positions and with less muscle activity.ConclusionsVisual input was important for children with CP to maintain a standing position. Without visual input the children who required support dropped into a further crouched position. The somatosensory and vestibular systems alone could not provide enough information about the body position in space without visual cues as a reference frame. In the children who stood without support, an intensified visual stimulus enhanced the ability to maintain a quiet standing position. It may be that impairments in the sensory systems are major contributors to the difficulties to stand erect in children with CP.

Vestibular and Oculomotor Function in Children with Cerebral Palsy: A Scoping Review

“…These studies reported that children with CP demonstrated higher sway frequency and amplitude, especially when the vestibular system was required to maintain balance (i.e., unstable surface with eyes closed). 25,26,[29][30][31]36 One article 30 also showed that these results are significantly different in subgroups of CP, for example between children who required support and those who do not. Without extensive testing, clinicians would not know if the balance impairments experienced by children with CP, typically attributed to a poor neural drive, would be compounded by an aberrant vestibular and/or oculomotor system.…”

“…Four of these studies were from the United States, 6,[26][27][28] and three articles were from Brazil. 13,14,29 Greece, 9,10 Sweden, 17,30 United Kingdom, 31,32 and Belgium 33,34 each produced two articles, while Italy, 11 Turkey, 25 Iran, 35 Canada, 8 Israel, 15 and China 36 each produced one article. Nine articles examined oculomotor function in children with CP.…”

“…Oculomotor Systems in Children with CP Eleven articles 17,[25][26][27][28][29][30][31][32]34,36 described vestibular and oculomotor integration through the following functions: static balance, eye-hand coordination, and head stability (Tables 5 and 6). Six articles examined static standing balance in children with CP compared to a control group of children who were typically developing.…”

“…25,26,[29][30][31]36 Four of them 25,26,31,36 measured static standing balance using force plates, either custom or commercially available systems, while two studies used a custom moving room 29 and a three-dimensional motion analysis system. 30 The common variable measured in these studies was the sway score, operationally defined as the mean center of pressure (COP) and the sway path length. These studies reported that children with CP demonstrated higher sway frequency and amplitude, especially when the vestibular system was required to maintain balance (i.e., unstable surface with eyes closed).…”

Topographical Working Memory in Children with Cerebral Palsy

“…This sign has been defined as characteristic for perceptual disorders in children with spastic CP (Ferrari et al, 2014). Moreover, proprioception deficits in the lower limbs in children with CP have been associated with motor disturbances during standing and walking (Bartonek et al, 2018;Damiano et al, 2013;Lidbeck et al, 2016;Wingert et al, 2009) where in the latter study during turning gait, difficulties in spatial orientation was believed to negatively influence locomotion.…”