RESUMEN
BACKGROUND: Postural instability is a classical characteristic of cerebral palsy (CP), but it has not been examined during functional play activity. Recent work has demonstrated that when motor tasks are made functionally more relevant, performance improves, even in children with movement pathology. It is possible that in a disease state, the underlying control mechanisms that are associated with healthy physiology must be elicited. OBJECTIVE: The study objective was to explore the utility of the functional play task methodology as a more rich and interpretable approach to the quantification of postural instability in children with CP. DESIGN: Postural stability measures obtained from a cross-sectional cohort of children with CP (n=30) were compared with stability measures taken from children with typical development (n=30) during a single measurement period. METHODS: Postural stability data were obtained with a portable force platform system. Postural sway was quantified during a precision manual functional play task. A baseline condition (no task) also was included. Postural sway variability and postural sway regularity were analyzed with analyses of variance. RESULTS: There was an apparent difference in postural control (greater irregularity, greater sway variability) during quiet stance between children with CP and peers with typical development; this difference was mitigated during the performance of the precision functional play task. LIMITATIONS: A small and nonprobability sample of convenience may limit the findings of this study. CONCLUSIONS: The findings illustrate flexibility and adaptability in the postural control system despite the pathological features associated with CP.
Asunto(s)
Parálisis Cerebral/fisiopatología , Parálisis Cerebral/rehabilitación , Evaluación de la Discapacidad , Equilibrio Postural/fisiología , Análisis y Desempeño de Tareas , Niño , Estudios Transversales , Femenino , Humanos , MasculinoRESUMEN
The purpose of this study was to determine whether signatures of adaptive postural control remain present in children with cerebral palsy (CP) when they performed a supra-postural task (i.e., a task performed above and beyond the control of posture) requiring them to balance a marble inside a tube held in the hands. Measures of center of pressure (COP) dynamics (how regular or predictable were the COP data as quantified by the sample entropy metric) and variability (as quantified by the COP standard deviation) were obtained from a sample of children with CP (n=30) and compared to the same measures taken from typically developing (TD) children. Children with CP demonstrated an apparent inefficiency in postural control (greater irregularity, greater sway variability) relative to TD peers during a quiet-stance (no supra-postural task) condition (p<.05). During supra-postural task performance, those differences were attenuated, though they remained statistically different (p<.05). The findings illustrate flexibility and adaptability in the postural control system, despite the pathological features associated with CP.
Asunto(s)
Parálisis Cerebral/fisiopatología , Parálisis Cerebral/rehabilitación , Equilibrio Postural/fisiología , Soporte de Peso/fisiología , Atención/fisiología , Niño , Femenino , Humanos , Masculino , Desempeño Psicomotor/fisiología , Rango del Movimiento Articular/fisiología , Valores de ReferenciaRESUMEN
OBJECTIVE: Our study is to investigate somatosensory dysfunction in children with spastic cerebral palsy (CP) using magnetoencephalography (MEG) and synthetic aperture magnetometry (SAM). METHODS: Six children with spastic CP and six age- and gender-matched typically developing children were studied using a 275-channel MEG system while their left and right index fingers were stimulated in random order. The latency and amplitude of somatosensory evoked magnetic fields were analyzed at sensor level. The patterns of high-gamma oscillations were investigated with SAM at source level. RESULTS: In comparison to the children with typical development, the latency of the first response of somatosensory evoked magnetic fields (SEFs) in the children with spastic CP was significantly delayed (p<0.05). High-gamma oscillations were identified in the somatosensory cortex in both children with CP and typical developing children. Interestingly, children with spastic CP had significantly higher incidence of ipsilateral activation in the somatosensory cortex following right and left finger stimulation, compared to typically developing children (p=0.05). CONCLUSION: The results suggest that children with spastic CP have a measurable delay of SEFs and high-gamma oscillations. The high rates of ipsilateral cortical activation imply the impairments of functional lateralization in the developing brain. This is the first MEG study to demonstrate abnormal high-gamma oscillations of somatosensory cortices representing the finger in children with spastic CP.
Asunto(s)
Parálisis Cerebral/fisiopatología , Magnetoencefalografía/métodos , Oscilometría , Corteza Somatosensorial/fisiopatología , Adolescente , Mapeo Encefálico , Niño , Estimulación Eléctrica/métodos , Femenino , Dedos/fisiología , Humanos , MasculinoRESUMEN
We demonstrated that postural responses to imposed optic flow are to some extent voluntary. In a moving room, participants either stood normally or were instructed to resist any influence of visible motion on their stance. When participants attempted to resist, coupling of body sway with motion of the room was significantly greater than when the eyes were closed, but was significantly reduced relative to coupling in the normal stance condition. The results indicate that the use of imposed optic flow for postural control is not entirely automatic or involuntary. This conclusion motivates a search for non-perceptual factors that may influence the degree to which body sway is coupled to imposed optic flow.
Asunto(s)
Percepción de Movimiento/fisiología , Orientación/fisiología , Postura/fisiología , Desempeño Psicomotor/fisiología , Volición , Adolescente , Adulto , Análisis de Varianza , Humanos , IntenciónRESUMEN
Static posturographic recordings were obtained from six Parkinson's patients and six age-matched, healthy control participants. The availability of vision and visuo-spatial cognitive load were manipulated. Postural sway patterns were analyzed using recurrence quantification analysis (RQA), which revealed differences in center of pressure (COP) dynamics between Parkinson's and control participants. AP COP trajectories for the Parkinson's group were not only significantly more variable than for the control group, but also exhibited distinct patterns of temporal dynamics. The visual manipulation did not differentially affect the two groups. No cognitive load effects were found. The results are generally consistent with the hypothesis that pathological physiological systems exhibit a tendency for less flexible, more deterministic dynamic patterns.
Asunto(s)
Enfermedad de Parkinson/fisiopatología , Equilibrio Postural/fisiología , Postura/fisiología , Sensación/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dinámicas no Lineales , Presión , Tiempo de Reacción/fisiología , Factores de TiempoRESUMEN
We compared the variability and spatiotemporal profile of postural sway of trained ballet dancers to college varsity track athletes under variations in the availability of vision and rigidity of the support surface. We found no differences between the groups according to the variability measures, but variability increased for both groups with eyes closed and on a foam surface. Recurrence quantification analysis revealed that the postural sway of dancers was less regular (lower recurrence), less stable (lower maxline), less complex (lower entropy), and more stationary (lower absolute trend) than that of track athletes. Dancers, possibly as a result of focused balance training, exhibited different dynamic patterns of postural sway.
Asunto(s)
Baile/fisiología , Equilibrio Postural/fisiología , Postura/fisiología , Deportes/fisiología , Adulto , Femenino , Humanos , MasculinoRESUMEN
We measured postural stability while participants simply stood or stood while performing a digit rehearsal task of varying levels of difficulty in order to examine the effects on postural control of concurrent short-term memory demands. The rehearsal task manipulation avoided factors that contaminate postural sway measurements, such as vocal articulation or visual fixation during posture data collection. When participants performed the more difficult digit tasks (longer digit strings), postural sway was reduced relative to when performing an easy version of the task (few digits). The results identified a complex relation between postural control and cognitive or attentional demands.