Arm load magnitude affects selective shoulder muscle activation

For isometric tasks, shoulder muscle forces are assumed to scale linearly with the external arm load magnitude, i.e., muscle force ratios are constant. Inverse dynamic modeling generally predicts such linear scaling behavior, with a critical role for the arbitrary load sharing criteria, i.e., the “cost function”. We tested the linearity of the relation between external load magnitude exerted on the humerus and shoulder muscle activation. Six isometric force levels ranging from 17 to 100% of maximal arm force were exerted in 24 directions in a plane perpendicular to the longitudinal axis of the humerus. The direction of maximum muscle activation, the experimentally observed so called Principal Action (PA), was determined for each force magnitude in 12 healthy subjects. This experiment was also simulated with the Delft Shoulder and Elbow Model (DSEM) using two cost functions: (1) minimizing muscle stress and (2) a compound, energy related cost function. PA, both experimental (PA_exp) and simulated (PA_sim), was expected not to change with arm forces magnitudes. PA_exp of the mm. trapezius pars descendens, deltoideus pars medialis and teres major changed substantially as a function of external force magnitude, indicating external load dependency of shoulder muscle activation. In DSEM simulations, using the stress cost function, small non-linearities in the muscle force–external load dependency were observed, originating from gravitational forces working on clavicular and scapular bone masses. More pronounced non-linearities were introduced by using the compound energy related cost function, but no similarity was observed between PA_exp and PA_sim.     

Coordination of a complex welfare system case: rehabilitation entity in Finland

The main purpose of this article is to analyse the institutional and political structures of the Finnish rehabilitation entity and the governmental efforts to improve the governance of the rehabilitation policy. Rehabilitation in Finland is a complex welfare system which has undergone several coordination attempts during the last two decades. The centrality of the coordination of this welfare system is obvious. Based on the content analysis of three Government's rehabilitation reports from 1994 to 2002 and their background papers, this article provides two main findings. First, the rehabilitation entity seems to be based on different funding strategies, different governing and different coordination models between the rehabilitation subsystems. Second, the governance discourse in the reports seems to be unchanging with a predominantly hierarchical mode. The article concludes with a discussion on the challenges to coordinate this kind of a complex welfare system as an entity and also how to overcome those challenges. Copyright © 2010 John Wiley & Sons, Ltd.     

Ethanol exposure during the early first trimester equivalent impairs reflexive motor activity and heightens fearfulness in an avian model

Prenatal alcohol exposure is a leading cause of childhood neurodevelopmental disability. The adverse behavioral effects of alcohol exposure during the second and third trimester are well documented; less clear is whether early first trimester-equivalent exposures also alter behavior. We investigated this question using an established chick model of alcohol exposure. In ovo embryos experienced a single, acute ethanol exposure that spanned gastrulation through neuroectoderm induction and early brain patterning (19-22 h incubation). At 7 days posthatch, the chicks were evaluated for reflexive motor function (wingflap extension, righting reflex), fearfulness (tonic immobility [TI]), and fear/social reinstatement (open-field behavior). Chicks exposed to a peak ethanol level of 0.23-0.28% were compared against untreated and saline-treated controls. Birds receiving early ethanol exposure had a normal righting reflex and a significantly reduced wingflap extension in response to a sudden descent. The ethanol-treated chicks also displayed heightened fearfulness, reflected in increased frequency of TI, and they required significantly fewer trials for its induction. In an open-field test, ethanol treatment did not affect latency to move, steps taken, vocalizations, defecations, or escape attempts. The current findings demonstrate that early ethanol exposure can increase fearfulness and impair aspects of motor function. Importantly, the observed dysfunctions resulted from an acute ethanol exposure during the period when the major brain components are induced and patterned. The equivalent period in human development is 3-4 weeks postconception. The current findings emphasize that ethanol exposure during the early first trimester equivalent can produce neurodevelopmental disability in the offspring.     

Brain activation associated with motor skill practice in children with developmental coordination disorder: an fMRI study

Children with developmental coordination disorder (DCD) have difficulty in learning new motor skills. At present, it is not known whether these children employ a different set of brain regions than typically developing (TD) children during skilled motor practice. Using functional magnetic resonance imaging, we mapped brain activity associated with skilled motor practice of a trail-tracing task in 7 children with DCD and 7 age-matched controls (aged 8-12 years). We indexed change in motor performance as a reduction in tracing error from early practice to retention. Children with DCD showed less blood-oxygen-level-dependent signal as compared to TD children in a network of brain regions associated with skilled motor practice: bilateral inferior parietal lobules (Brodmann Area (BA) 40), right lingual gyrus (BA 18), right middle frontal gyrus (BA 9), left fusiform gyrus (BA 37), right cerebellar crus I, left cerebellar lobule VI, and left cerebellar lobule IX. While no statistically significant differences were detected, effect size testing revealed that children with DCD demonstrated poorer tracing accuracy than TD children at retention (d = 0.48). Our results suggest that, compared to TD peers, children with DCD demonstrate under-activation in cerebellar-parietal and cerebellar-prefrontal networks and in brain regions associated with visual-spatial learning. These data suggest a neurobiological correlation with impaired learning of motor skills in children with DCD, which will need to be confirmed with a larger sample.     

The relationship of community‐based nurse care coordination to costs in the medicare and medicaid programs

The purpose of this evaluation was to study the relationship of nurse care coordination (NCC) to the costs of Medicare and Medicaid in a community‐based care program called Missouri Care Options (MCO). A retrospective cohort design was used comparing 57 MCO clients with NCC to 80 MCO clients without NCC. Total cost was measured using Medicare and Medicaid claims databases. Fixed effects analysis was used to estimate the relationship of the NCC intervention to costs. Controlling for high resource use on admission, monthly Medicare costs were lower ($686) in the 12 months of NCC intervention (p = .04) while Medicaid costs were higher ($203; p = .03) for the NCC group when compared to the costs of MCO group. © 2010 Wiley Periodicals, Inc. Res Nurs Health 33:235–242, 2010     

Online motor control in children with developmental coordination disorder: chronometric analysis of double‐step reaching performance

Background Although there are a number of plausible accounts to explain movement clumsiness in children [or developmental coordination disorder (DCD)], the cause(s) of the disorder remain(s) an issue of debate. One aspect of motor control that is particularly important to the fluid expression of skill is rapid online control (ROC). Data on DCD have been conflicting. While some recent work using double‐step reaching suggests no difficulty in online control, others suggest deficits (e.g. based on sequential pointing). To help resolve this debate, we suggest two things: use of recent neuro‐computational models as a framework for investigating motor control in DCD, and more rigorous investigation of double‐step reaching. Our working assumption here is that ROC is only viable through the seamless integration of predictive (or forward) models of movement and feedback‐based mechanisms. Aim The aim of this chronometric study was to explore ROC in children with DCD using a double‐step reaching paradigm. We predicted slower online adjustments in DCD based on the argument that these children manifest a core difficulty in predictive control. Methods Participants were a group of 17 children with DCD and 27 typically developing children aged between 7 and 12 years. Visual targets were presented on a 17‐inch LCD touch screen, inclined to an angle of 15° from horizontal. The children were instructed to press each target as it appeared as quickly and accurately as possible. For 80% of the trials, the central target location remained unchanged for the duration of the movement (non‐jump trials), while for the remaining 20% of trials, the target jumped at movement onset to one of the two peripheral locations (jump trials). Reaction time (RT), movement time (MT) and reaching errors were recorded. Results For both groups, RT did not vary according to trial condition, while children with DCD were slower to initiate movement. Further, the MT of children with DCD was prolonged to a far greater extent on jump trials relative to controls, with a large effect size. As well, children with DCD committed significantly more errors, notably a reduced ability to inhibit central responses on jump trials. Conclusion Our findings help reconcile some disparate findings in the literature using similar tasks. The pattern of performance in children with DCD suggests impairment in the ability to make rapid online adjustments that are based on a predictive (or internal) model of the action. These results pave the way for future kinematic investigation.     

Staff acceptance of video monitoring for coordination: a video system to support perioperative situation awareness

Aim. To understand staff acceptance of a remote video monitoring system for operating room (OR) coordination. Background. Improved real‐time remote visual access to OR may enhance situational awareness but also raises privacy concerns for patients and staff. Design. Survey. Methods. A system was implemented in a six‐room surgical suite to display OR monitoring video at an access restricted control desk area. Image quality was manipulated to improve staff acceptance. Two months after installation, interviews and a survey were conducted on staff acceptance of video monitoring. Results. About half of all OR personnel responded (n = 63). Overall levels of concerns were low, with 53% rated no concerns and 42% little concern. Top two reported uses of the video were to see if cases are finished and to see if a room is ready. Viewing the video monitoring system as useful did not reduce levels of concern. Staff in supervisory positions perceived less concern about the system’s impact on privacy than did those supervised (p < 0·03). Concerns for patient privacy correlated with concerns for staff privacy and performance monitoring. Technical means such as manipulating image quality helped staff acceptance. Conclusions. Manipulation of image quality resulted overall acceptance of monitoring video, with residual levels of concerns. OR nurses may express staff privacy concern in the form of concerns over patient privacy. Relevance to clinical practice. This study provided suggestions for technological and implementation strategies of video monitoring for coordination use in OR. Deployment of communication technology and integration of clinical information will likely raise concerns over staff privacy and performance monitoring. The potential gain of increased information access may be offset by negative impact of a sense of loss of autonomy.     

Coordinating mental health care across primary care and schools: ADHD as a case example

Although primary care practices and schools are major venues for the delivery of mental health services to children, these systems are disconnected, contributing to fragmentation in service delivery. This paper describes barriers to collaboration across the primary care and school systems, including administrative and fiscal pressures, conceptual and linguistic differences between health care and educational professionals, role restrictions among professionals, and privacy laws. Strategies for overcoming these barriers, which can be applied in both primary care and school settings, are described in this paper. This paper has a primary focus on children with attention-deficit/hyperactivity disorder, but the principles and strategies described are applicable to children with a range of mental health and health conditions.     

Task experience influences coordinative structures and performance variables in learning a slalom ski‐simulator task

The experiment investigated the progressions of the qualitative and quantitative changes in the movement dynamics of learning the ski‐simulator as a function of prior‐related task experience. The focus was the differential timescales of change in the candidate collective variable, neuromuscular synergies, joint motions, and task outcome as a function of learning over 7 days of practice. Half of the novice participants revealed in day 1 a transition of in‐phase to anti‐phase coupling of center of mass (CoM)‐platform motion whereas the remaining novices and experienced group all produced on the first trial an anti‐phase CoM‐platform coupling. The experienced group also had initially greater amplitude and velocity of platform motion—a performance advantage over the novice group that was reduced but not eliminated with 7 days of practice. The novice participants who had an in‐phase CoM‐platform coupling on the initial trials of day 1 also showed the most restricted platform motion in those trials. Prior‐related practice experience differentially influenced the learning of the task as evidenced by both the qualitative organization and the quantitative motion properties of the individual degrees of freedom (dof ) to meet the task demands. The findings provide further evidence to the proposition that CoM‐platform coupling is a candidate collective variable in the ski‐simulator task that provides organization and boundary conditions to the motions of the individual joint dof and their couplings.