Postural Stability in Children with High Sacral Level Spina Bifida: Deviations from a Control Group

Abstract

Objective: To assess static and dynamic postural stability changes in children with high sacral level spina bifida.

Methods: Thirty-five children with high sacral level spina bifida and 35 age-matched healthy controls were enrolled. Their lower extremity muscle strengths and static and dynamic postural stability parameters were measured with the use of a dynamometer and the NeuroCom Balance Master^® device, respectively. Functional gait and balance were evaluated using the five times sit-to-stand test (5STS) and the 6-minute walk test (6MWT). Spinal, hip, and ankle deformities of the patient group were measured by radiologic evaluation.

Results: In comparison with controls, patients were found to have lower ankle dorsiflexion and plantar-flexion strength, increased 5STS duration, and decreased 6MWT distance while both static and dynamic postural stability parameters were significantly different. Bilateral ankle muscle strengths were found to be negatively correlated with postural stability parameters. The presence of hydrocephalus or meningomyelocele in the patient group was found to have negative effects on static postural stability.

Conclusion: Static and dynamic postural stability is affected even in children with high sacral level spina bifida who are expected to have best condition in this patient population. The ankle muscle strength is the main factor influencing these changes.     

Motor learning of cue-dependent pull-force changes during an isometric precision grip task

The “raspberry task” represents a precision grip task that requires continuous adjustment of grip and pull forces. During this task subjects grip a specialized grip rod and have to increase the pull force linearly while the rod is locked. The aim of this study was to determine whether an associated, initially neutral cue is able to evoke pull-force changes in the raspberry task. A standard delay paradigm was used to study cued pull-force changes during an ongoing movement resulting in unloading. Pull force and EMG activity of hand and arm muscles were recorded from 13 healthy, young subjects. The cue was associated with a complex change in motor behavior.In this task, cued force changes take place more rapidly than in protective reflex systems (in median after the second presentation of the cueing stimulus). A cued force change was detectable in two-thirds of paired trials. Although the force change is produced by a decrease of the EMG activity in several grip- and pull-force-producing muscles, the most significant effect in the majority of the subjects was an increase of the activity of the flexor carpi ulnaris muscle which antagonises corresponding pull-force-producing muscles. Cued force changes require adequately and precisely controlled activation of the muscle groups involved in the movement.     

The relation between cognitive and motor performance and their relevance for children’s transition to school: A latent variable approach

Both theoretically and empirically there is a continuous interest in understanding the specific relation between cognitive and motor development in childhood. In the present longitudinal study including three measurement points, this relation was targeted. At the beginning of the study, the participating children were 5–6-year-olds. By assessing participants’ fine motor skills, their executive functioning, and their non-verbal intelligence, their cross-sectional and cross-lagged interrelations were examined. Additionally, performance in these three areas was used to predict early school achievement (in terms of mathematics, reading, and spelling) at the end of participants’ first grade. Correlational analyses and structural equation modeling revealed that fine motor skills, non-verbal intelligence and executive functioning were significantly interrelated. Both fine motor skills and intelligence had significant links to later school achievement. However, when executive functioning was additionally included into the prediction of early academic achievement, fine motor skills and non-verbal intelligence were no longer significantly associated with later school performance suggesting that executive functioning plays an important role for the motor-cognitive performance link.     

Cognitive and motor deficits in older adults with HIV infection: Comparison with normal ageing and Parkinson’s disease

Despite the life-extending success of antiretroviral pharmacotherapy in HIV infection (HIV), the prevalence of mild cognitive impairment in HIV remains high. Near-normal life expectancy invokes an emerging role for age–infection interaction and a potential synergy between immunosenescence and HIV-related health factors, increasing risk of cognitive and motor impairment associated with degradation in corticostriatal circuits. These neural systems are also compromised in Parkinson’s disease (PD), which could help model the cognitive deficit pattern in HIV. This cross-sectional study examined three groups, age 45–79 years: 42 HIV, 41 PD, and 37 control (CTRL) participants, tested at Stanford University Medical School and SRI International. Neuropsychological tests assessed executive function (EF), information processing speed (IPS), episodic memory (MEM), visuospatial processing (VSP), and upper motor (MOT) speed and dexterity. The HIV and PD deficit profiles were similar for EF, MEM, and VSP. Although only the PD group was impaired on MOT compared with CTRL, MOT scores were related to cognitive scores in HIV but not PD. Performance was not related to depressive symptoms, socioeconomic status, or CD4⁺ T-cell counts. The overlap of HIV-PD cognitive deficits implicates frontostriatal disruption in both conditions. The motor-cognitive score relation in HIV provides further support for the hypothesis that these processes share similar underlying mechanisms in HIV infection possibly expressed with or exacerbated by ageing.     

The Effects of Attentional Focus Instructions and Task Difficulty in a Paced Fine Motor Skill

Abstract

An external focus of attention is considered superior to an internal focus for learning and performance. However, findings specific to changing the task difficulty are inconsistent. The present study used a reciprocal aiming task to determine the effects of attentional focus on motor performance using speed-accuracy paradigm. We constrained timing to examine how internal and external focus of attention influenced accuracy when task difficulty changes. The results indicated greater accuracy on the right target and greater consistency on both targets for the external focus condition, regardless of task difficulty. Our results uniquely demonstrated how instruction modified a speed-accuracy task.     

Crawling in and out of sleep

The goal of the study was to examine the link between motor attainments and sleep–wake regulation by comparing the sleep characteristics of infants who are crawling with the sleep of same‐age infants who have not yet acquired the locomotion milestone. The participants were 59 healthy 8‐month‐old infants with no developmental delays, who were recruited through well‐baby clinics and childcare centers. The measurements included objective sleep recordings (actigraphy), sleep questionnaire, and motor milestones checklist. The main finding was that the sleep of crawlers was more fragmented in comparison to the sleep of pre‐crawlers. While the findings of this report give support to the hypothesized link between sleep regulation and motor development, more studies are needed to clarify why crawling might provide a marker of nightwaking. In discussing the results, it is proposed that the association between fragmented sleep and crawling could be related to maturational, constitutional, and relational factors. Copyright © 2005 John Wiley & Sons, Ltd.     

Is Segmental Trunk Control Related to Gross Motor Performance in Healthy Preterm and Full-Term Infants?

Abstract

The authors’ aim was to verify the correlation between segmental trunk control and gross motor performance in healthy preterm (PT) and full-term (FT) infants aged 6 and 7?months and to verify if there are differences between groups. All infants were assessed at 6 and 7?months by means of Segmental Assessment of Trunk Control (SATCo) to identify the exact level of segmental trunk control and Alberta Infant Motor Scale (AIMS) to measure gross motor performance. A significant correlation between segmental trunk control and gross motor performance was found in healthy PT infants at 7?months and FT infants at 6?months. PT infants showed a delay on segmental trunk control at 6 and 7?months and in supported standing posture at 6?months compared with FT infants. Segmental trunk control and gross motor performance showed an important relationship in healthy PT and FT infants, mainly in sitting posture.     

Mental imagery and fiction

Fictions evoke imagery, and their value consists partly in that achievement. This paper offers analysis of this neglected topic. Section 2 identifies relevant philosophical background. Section 3 offers a working definition of imagery. Section 4 identifies empirical work on visual imagery. Sections 5 and 6 criticize imagery essentialism, through the lens of genuine fictional narratives. This outcome, though, is not wholly critical. The expressed spirit of imagery essentialism is to encourage philosophers to ‘put the image back into the imagination’. The weakened conclusion is that while an image is not essential to imagining, it should be returned to our theories of imagination.