Simone R. Caljouw

Exergaming for elderly:: effects of different types of game feedback on performance of a balance task.

Balance training to improve postural control in elderly can contribute to the prevention of falls. Video games that require body movements have the potential to improve balance. However, research about the effects of type of visual feedback (i.e. the exergame) on the quality of movement and experienced workout intensity is scarce. In this study twelve healthy older and younger subjects performed anterior-posterior or mediolateral oscillations on a wobble board, in three conditions: no feedback, real-time visual feedback, and real-time visual feedback with a competitive game element. The Elderly moved slower, less accurately and more irregularly than younger people. Both feedback conditions ensured a more controlled movement technique on the wobble-board and increased experienced workout intensity. The participants enjoyed the attention demanding competitive game element, but this game did not improve balance performance more than interacting with a game that incorporated visual feedback. These results show the potential of exergames with visual feedback to enhance postural control.

Intersection assistance: A safe solution for older drivers?

Within the next few decades, the number of older drivers operating a vehicle will increase rapidly (Eurostat, 2011). As age increases so does physical vulnerability, age-related impairments, and the risk of being involved in a fatal crashes. Older drivers experience problems in driving situations that require divided attention and decision making under time pressure as reflected by their overrepresentation in at-fault crashes on intersections. Advanced Driver Assistance Systems (ADAS) especially designed to support older drivers crossing intersections might counteract these difficulties. In a longer-term driving simulator study, the effects of an intersection assistant on driving were evaluated. 18 older drivers (M=71.44 years) returned repeatedly completing a ride either with or without a support system in a driving simulator. In order to test the intersection assistance, eight intersections were depicted for further analyses. Results show that ADAS affects driving. Equipped with ADAS, drivers allocated more attention to the road center rather than the left and right, crossed intersections in shorter time, engaged in higher speeds, and crossed more often with a critical time-to-collision (TTC) value. The implications of results are discussed in terms of behavioral adaptation and safety.

Behavioral adaptation of young and older drivers to an intersection crossing advisory system

An advanced driver assistance system (ADAS) provided information about the right of way regulation and safety to cross an upcoming intersection. Effects were studied in a longer-term study involving 18 healthy older drivers between the ages of 65 and 82 years and 18 healthy young drivers between the ages of 20 and 25 years. Participants repeatedly drove 25 km city routes in eight sessions on separate days over a period of two months in a driving simulator. In each age group, participants were randomly assigned to the control (no ADAS) and treatment (ADAS) group. The control group completed the whole experiment without the ADAS. The treatment group drove two sessions without (sessions 1 and 7) and six times with ADAS. Results indicate effects of ADAS on driving safety for young and older drivers, as intersection time and percentage of stops decreased, speed and critical intersection crossings increased, the number of crashes was lower for treatment groups than for control groups. The implications of results are discussed in terms of behavioral adaptation and safety.

Aging affects attunement in perceiving length by dynamic touch

Earlier studies have revealed age-dependent differences in perception by dynamic touch. In the present study, we examined whether the capacity to learn deteriorates with aging. Adopting an ecological approach to learning, the authors examined the process of attunement—that is, the changes in what informational variable is exploited. Young and elderly adults were trained to perceive the lengths of unseen, handheld rods. It was found that the capacity to attune declines with aging: Contrary to the young adults, the elderly proved unsuccessful in learning to detect the specifying informational variables. The fact that aging affects the capacity to attune sets a new line of research in the study of perception and perceptual-motor skills of elderly. The authors discuss the implications of their findings for the ongoing discussions on the ecological approach to learning.

Differential effects of a visual illusion on online visual guidance in a stable environment and online adjustments to perturbations

In the reported, experiment participants hit a ball to aim at the vertex of a Müller-Lyer configuration. This configuration either remained stable, changed its shaft length or the orientation of the tails during movement execution. A significant illusion bias was observed in all perturbation conditions, but not in the stationary condition. The illusion bias emerged for perturbations shortly after movement onset and for perturbations during execution, the latter of which allowed only a minimum of time for making adjustments (i.e., approx.170 ms). These findings indicate that allocentric information is exploited for online control when people make rapid adjustments in response to a sudden change in the environment and not when people guide their limb movements to interact with a stable environment.

Differences between Young and Older Adults in the Control of Weight Shifting within the Surface of Support

An important reason for falling in elderly is incorrect weight-shifting. In many daily life activities quick and accurate weight-shifting is needed to maintain balance and to prevent from falling. The present study aims to gain more insight in age-related differences in the control of weight-shifting. Nine healthy older adults (70.3±6.9 years) and twelve young adults (20.9±0.5 years) participated in the study. They performed a weight shifting task by moving the bodys center of pressure, represented by a red dot on a screen, in different directions, towards targets of different sizes and at different distances projected on a screen. Movement time, fluency and accuracy of the movement were determined. Accuracy was quantified by the number of times the cursor hit the goal target before a target switch was realized (counts on goal) and by the time required to realize a target switch after the goal target was hit by the cursor for the first time (dwelling time). Fluency was expressed by the maximal deviation of the performed path with respect to the ideal path and the number of peaks, or inflections in the performed path. Significant main effects of target size, target distance and age on all outcome measures were found. With decreasing target size, increasing target distance and increasing age, movement time significantly increased and fluency and accuracy significantly decreased (i.e. increased number of peaks, maximal deviation, number of times on the goal target and longer dwelling time around the goal target). In addition, significant interaction effects of size*age and distance*age were found. Older adults needed more time to perform the weight-shifting task and their movements were less fluent and accurate compared to younger adults, especially with increasing task difficulty. This indicates that elderly might have difficulties with executing an adequate adaptation to a perturbation in daily life.

A systematic review into the effectiveness of hand exercise therapy in the treatment of rheumatoid arthritis

Hand exercises are often part of the treatment of hand rheumatoid arthritis; however, it is still unclear whether and what type of exercises is effective in the treatment of this condition. Therefore, a systematic review into the effectiveness of hand exercises in the treatment of hand rheumatoid arthritis has been performed. Studies were identified in the literature databases by predefined search criteria. The eight included studies are peer-reviewed studies published between 2000 and 2014. Hand exercises differed between studies, but always included resistance and/or active range of motion exercises. Grip strength in various grip types (power grip, key pinch, precision pinch and tripod pinch) was found to improve by hand exercise therapy without having adverse effects on pain or disease activity. Adaptations in the range of motion in response to hand exercise therapy were less pronounced. There appears to be some transfer from the improvements on the body functioning level to the level of daily functioning, with the largest improvements found on grip ability. With regard to the intervention content, there was some evidence in favour of a longer therapy duration and a higher therapy intensity. No conclusions could be drawn on the effectiveness of the different types of exercises. Collectively, the studies indicate that hand exercises may have positive effects on strength and some aspects of daily functioning without aggravating disease activity or pain, although caution should be taken for subjects in the exacerbation period.

Postural control of elderly: moving to predictable and unpredictable targets.

Impaired postural control with muscle weakness is an important predictor of falls within the elderly population.Particular daily activities that require weight shifting in order to be able to reach a specific target (a cup on a table) require continuous adjustments to keep the bodys center of mass balanced. In the present study postural control was examined in healthy elderly and young subjects during a task in which subjects had to move the bodys center of mass towards a virtual target on a screen that appeared at predictable and unpredictable locations. Postural control decreased with unpredictable targets, e.g. movement time was larger, trajectories more irregular. The results indicate that even though older individuals clearly benefitted from the early release of target location information, young individuals improved even more when target information became available.This indicates that the young were better able to use this information prospectively for executing the target directed movement quickly and accurately.

No single factor has priority in action development a tribute to Esther Thelen's legacy.

Among Esther Thelens most important contributions to developmental theory is that there is no single factor that has priority in driving development. In this paper, we discuss how this notion influenced our research on perceptual-motor development. We show that multiple factors constrain perceptual-motor development, but that a relatively minor change in one of them may lead to significant changes in the observed perceptual-motor behavior.

Longer-term effects of ADAS use on speed and headway control in drivers diagnosed with Parkinson's disease

Objective: An advanced driver assistance system (ADAS) provided information about speed limits, speed, speeding, and following distance. Information was presented to the participants by means of a head-up display. Methods: Effects of the information on speed and headway control were studied in a longer-term driving simulator study including 12 repeated measures spread out over 4 weeks. Nine healthy older drivers between the ages of 65 and 82 years and 9 drivers between the ages of 68 and 82 years diagnosed with Parkinsons disease (PD) participated in the study. Within the 4 weeks, groups completed 12 consecutive sessions (10 with ADAS and 2 without ADAS) in a driving simulator. Results: Results indicate an effect of ADAS use on performance. Removing ADAS after short-term exposure led to deterioration of performance in all speed measures in the group of drivers diagnosed with PD. Conclusions: These results suggest that provision of traffic information was utilized by drivers diagnosed with PD in order to control their speed.