Haptic Information Improvement on Postural Sway is Information-Dependent But Not Influenced by Cognitive Task.

Young adults reduce their sway in both light touch (LT) and anchor systems (AS), however, the cognitive involvement in these tasks is unknown. This study investigated postural control in young adults standing upright using either LT or AS, concomitantly with a cognitive task (counting). Nine adults (26 ± 7.4 years) stood in the upright tandem stance with eyes closed, with/without LT, AS (force <2 N), and a cognitive task. The mean sway amplitude of the trunk, right wrist, and shoulder ellipse area, as well as the mean force during LT and AS were obtained. The cognitive task did not influence the magnitude of trunk sway or the mean force in the LT and AS conditions. The trunk sway magnitude was reduced in the AS and even further in LT. Wrist and shoulder variability was larger in the AS than in the LT. Based on these results, we conclude that enhanced sensory cues provided by LT and AS reduce trunk sway with little or no attentional demands.

Visually guided eye movements reduce postural sway in dyslexic children.

Dyslexic children present poorer postural control performance than their peers, perhaps due to different patterns of eye movements. It has been shown that guided eye movements decrease magnitude of body sway in young and older adults, but there is no evidence whether the search for visual information that occurs during eye movements affects postural control in dyslexic children. The aim of this study was to examine the use of guided eye movements and its pattern in the performance of postural control of dyslexic children during upright quiet stance. Twelve children with dyslexia (10.8 ± 1.1 years old) and 12 non-dyslexic children (10.4 ± 1.5 years old) participated in this study. All children were instructed to maintain an upright quiet stance for 60 s either fixating on a target (fixation condition) displayed 1 m ahead in the center of a monitor at eye level, or performing eye movements to follow a target displayed on one side of a monitor, then disappearing and reappearing immediately on the opposite side with a frequency of 0.5 Hz (guided condition). Three trials for each condition were registered. Body sway was measured with an IRED (OPTOTRAK) placed on the children's back. Eye movements were tracked using eye-tracking glasses (ETG 2.0 - SMI). Dyslexic children swayed with larger amplitude under both fixation and guided conditions than non-dyslexic children. Both dyslexic and non-dyslexic children reduced postural sway magnitude under the guided compared to the fixation condition. All children were able to modulate eye movement according to the conditions (fixation and guided) and no difference in eye movements was observed between dyslexic and non-dyslexic children. Eye movements are modulated similarly based upon the visual conditions in dyslexic and non-dyslexic children, and dyslexic children are capable of using available visual information during eye movements to improve postural control, though they do not equal the performance of non-dyslexic children. Eye movement patterns seem not to be related to poor performance of postural control in dyslexic children.

Gait alterations during walking with partial body weight supported on a treadmill and over the ground.

Understanding the changes induced by body weight support (BWS) systems when non-disabled adults walk can help develop appropriate rehabilitation protocols. The purpose of this study was to investigate spatial-temporal gait alterations during walking with BWS on a treadmill and over the ground. Fourteen non-disabled young adults (including seven women) walked over the ground and on a treadmill with 0%, 10%, and 20% of BWS at 80% of their self-selected comfortable walking speed (baseline). The stride length and speed, step length, and stance and double-limb support durations were calculated and compared among the different conditions. The non-disabled adults modulated their spatial-temporal gait parameters according to the surface and percentage of BWS. They walked with shorter and slower strides and shorter steps and spent more time in contact with the support surface as they walked on the treadmill than as they did over the ground. Walking on the treadmill promoted less variability and a higher rate of change than did walking over the ground. Both the surface and amount of BWS should be taken into consideration when using BWS systems for (re)learning and/or reestablishing gait.

Analysis of partial body weight support during treadmill and overground walking of children with cerebral palsy.

OBJECTIVE: to analyze the spatial-temporal characteristics and joint angles during overground walking without body weight support (BWS) and with 0% and 30% BWS, and during treadmill walking with the same BWS in children with cerebral palsy. METHODS: six children with hemiplegic and spastic cerebral palsy (7.70 ± 1.04 years old) were videotaped during overground walking at a comfortable speed with no BWS, with 0% and 30% BWS, and during treadmill walking with 0% and 30% BWS. Reflective markers were placed over main bony landmarks in both body sides to register the coordinates "x", "y", "z". RESULTS: during overground walking, children walked faster and presented longer and faster strides, longer duration of single-stance and swing periods, and shorter duration of double-stance period, than treadmill walking, regardless of BWS use. The hip was the only joint that presented a difference between body sides and experimental conditions; i.e. range of motion (ROM) was reduced in the plegic side when compared to the nonplegic side, and during overground walking without BWS when compared to 30% BWS. CONCLUSION: children with hemiplegic and spastic cerebral palsy were able to walk overground and on a treadmill with different percentages of BWS, and their performance was superior during overground walking, regardless of BWS use.

Análise do uso de suporte parcial de peso corporal em esteira e em piso fixo durante o andar de crianças com paralisia cerebral / Analysis of partial body weight support during treadmill and overground walking of children with cerebral palsy

OBJETIVO: Analisar características espaço-temporais e ângulos articulares de crianças com paralisia cerebral andando sem o uso de suporte parcial de peso corporal (SPPC) em piso fixo e com 0 por cento e 30 por cento de SPPC em piso fixo e em esteira. MÉTODOS: Seis crianças com paralisia cerebral hemiplégica espástica (7,70±1,04 anos) foram filmadas andando com velocidade confortável sem o uso de SPPC, com 0 por cento e 30 por cento de SPPC em piso fixo e com 0 por cento e 30 por cento de SPPC em esteira. Marcadores refletivos foram afixados nos principais pontos anatômicos dos dois hemicorpos para registro das coordenadas "x", "y", "z". RESULTADOS: As crianças andaram mais rapidamente e com passadas mais longas e mais rápidas, com duração dos períodos de apoio simples e balanço maiores e apoio duplo menor no piso fixo do que na esteira, independentemente do uso do SPPC. O quadril foi a única articulação que apresentou diferenças entre os hemicorpos e entre as condições, sendo que o hemicorpo plégico apresentou menor amplitude de movimento (ADM) que o hemicorpo não plégico, e a ADM foi maior na condição sem o uso de SPPC do que com 30 por cento de SPPC em piso fixo. CONCLUSÃO: Crianças com paralisia cerebral hemiplégica espástica são capazes de andar em piso fixo e esteira com diferentes porcentagens de SPPC, sendo que seus desempenhos foram melhores no piso fixo, independentemente do uso de SPPC, do que na esteira.

OBJECTIVE: To analyze the spatial-temporal characteristics and joint angles during overground walking without body weight support (BWS) and with 0 percent and 30 percent BWS, and during treadmill walking with the same BWS in children with cerebral palsy. METHODS: Six children with hemiplegic and spastic cerebral palsy (7.70 ± 1.04 years old) were videotaped during overground walking at a comfortable speed with no BWS, with 0 percent and 30 percent BWS, and during treadmill walking with 0 percent and 30 percent BWS. Reflective markers were placed over main bony landmarks in both body sides to register the coordinates "x", "y", "z". RESULTS: During overground walking, children walked faster and presented longer and faster strides, longer duration of single-stance and swing periods, and shorter duration of double-stance period, than treadmill walking, regardless of BWS use. The hip was the only joint that presented a difference between body sides and experimental conditions; i.e. range of motion (ROM) was reduced in the plegic side when compared to the nonplegic side, and during overground walking without BWS when compared to 30 percent BWS. CONCLUSION: Children with hemiplegic and spastic cerebral palsy were able to walk overground and on a treadmill with different percentages of BWS, and their performance was superior during overground walking, regardless of BWS use.