Nina Skjæret

The influence of center-of-mass movements on the variation in the structure of human postural sway

The present article investigates the influence of center-of-mass movements on the variation of the structure in human postural sway. Twelve healthy younger persons performed 60s quiet standing, 60s relaxed standing, and 10 min relaxed standing on two force plates. Center-of-pressure (CoP) and gravitational line (GL) profiles were calculated from the ground reaction forces and moments. The temporal variation of CoP structure was calculated by the local scaling exponent h(t) and a Monte Carlo surrogate test was used to identify phase couplings between temporal scales. The range of variation of h(t) was significantly larger in relaxed standing compared to quiet standing (p<0.00001) and highly correlated with the range of GL movements (r>0.76, p<0.001). However, the variation in h(t) was not generated by the GL movements because the CoP-GL traces was close to identical variation in h(t) (r>0.95, p<0.00001). The Monte Carlo surrogate test indicated the presence of intermittent phase couplings between the temporal scales of both CoP traces and the CoP-GL residuals in the periods with GL movements. The present results suggest that human posture is controlled by intermittent phase coupling of the CoP and GL movements. Furthermore, the investigation of the variation in CoP structure might extend existing theories of changes in postural control for example older persons and patients with a neurodegenerative disease.

Usability and acceptability of balance exergames in older adults: A scoping review:

Serious games (exergames) have the potential to be effective for postural balance and increasing muscle strength. Several games have been developed to increase physical fitness and balance among older adults. However, it is unclear to which degree usability and acceptability of exergames for older adults have been evaluated. The aim of this study was to summarize usability evaluation and acceptability of studies in older adults. We conducted a scoping review on studies focusing on usability of exergames for older adults. The result shows that older adults consider usability and acceptability of exercise video games good. The review shows that longitudinal studies mainly use off-the-shelf exergame and evaluated game effectiveness and acceptability, whereas cross-sectional studies focus on interactional experience. Studies varied in their approaches to measure usability and acceptability of exergames for older adults. There is a need for a systematic developmental approach to involve older adults in development of exergames for longitudinal studies.

Designing Smart Home Technology for Fall Prevention in Older People

Falls in older people constitute one of the major challenges in healthcare. It is important to design technologies that can help prevent falls and improve falls management. Smart home technology could be of importance in this context, but the technology has to be user-centred or adapted to be useful in this particular context. This study assessed usability of paper and interactive prototypes of a smart home touch screen panel. The study implemented five scenarios related to fall risk, fall assessment and exercise guidance, designing a smart home interface for independent living in general and fall management in particular. A usability evaluation showed that older people had positive experiences when using the touch screen interface. The study demonstrated the need for user-centred interfaces for older people in the context of falls prevention.

An Exergame Concept for Improving Balance in Elderly People

Video exercise games (exergames) are becoming increasingly popular among elderly people. Many elderly experience reduced balance and muscle strength which make them at increased risk of falling. Muscle strength and balance training are the key components for preventing function decline and falls at old age. Exergames that are to be used among elderly users should be specifically designed for this group of people. This study aims to design and evaluate an exergame concept developed to fit the need and preferences of elderly users. First, seven elderly people tested three commercially available exergames. Feedback from focus group interviews revealed that the design of the existing exergames should be simplified and more closely related to activities that can be associated with older people’s daily life. Based on the feedback a new exergame concept “in nature” was designed. The new exergame concept had a simple design, and included balance and muscle strengthening exercises related to real life activities. In the results of the workshop, the study provides eight design recommendations for exergame design for seniors.