Kinect-based choice reaching and stepping reaction time tests for clinical and in-home assessment of fall risk in older people: a prospective study

Background

Quick protective reactions such as reaching or stepping are important to avoid a fall or minimize injuries. We developed Kinect-based choice reaching and stepping reaction time tests (Kinect-based CRTs) and evaluated their ability to differentiate between older fallers and non-fallers and the feasibility of administering them at home.

Methods

A total of 94 community-dwelling older people were assessed on the Kinect-based CRTs in the laboratory and were followed-up for falls for 6 months. Additionally, a subgroup (n?=?20) conducted the Kinect-based CRTs at home. Signal processing algorithms were developed to extract features for reaction, movement and the total time from the Kinect skeleton data.

Results

Nineteen participants (20.2 %) reported a fall in the 6 months following the assessment. The reaction time (fallers: 797?±?136 ms, non-fallers: 714?±?89 ms), movement time (fallers: 392?±?50 ms, non-fallers: 358?±?51 ms) and total time (fallers: 1189?±?170 ms, non-fallers: 1072?±?109 ms) of the reaching reaction time test differentiated well between the fallers and non-fallers. The stepping reaction time test did not significantly discriminate between the two groups in the prospective study. The correlations between the laboratory and in-home assessments were 0.689 for the reaching reaction time and 0.860 for stepping reaction time.

Conclusion

The study findings indicate that the Kinect-based CRT tests are feasible to administer in clinical and in-home settings, and thus represents an important step towards the development of sensor-based fall risk self-assessments. With further validation, the assessments may prove useful as a fall risk screen and home-based assessment measures for monitoring changes over time and effects of fall prevention interventions.

     

中国人口的不确定性研究

文章对2000年人口普查所反映的生育水平、出生性别比和人口年龄结构等主要人口指标存在的不确定性进行了梳理,并运用概率人口预测方法系统讨论了中国未来人口变动趋势过程中相关人口变量的不确定性问题。结果显示,当前对中国生育率水平、出生性别比和低龄儿童人口数量的估计都存在很大的差异。这些差异直接影响中国人口目前和未来的不确定性。     

Qualifikation von Ausbildungssupervisoren in der Sozialen Arbeit – Kontexte,Methoden und Erfahrungen

This article moots the issue of how to support students of social work and social pedagogy to develop the prerequisites for a professional exercise within their future vocational role by dint of supervision. Academical training has to offer spaces for reflecting the relationship between clients and their assistants and for the student’s self-development as well. Methodical settings are reflected for the vocational training of students. Of what kind are the relationships between knowledge transfer, practical guidance and supervision? This article pleads for supervision as an educational program and specifies the qualifications for supervisors.     

Gambling as a function of gender and Sensation Seeking

This study examined the relation of gender and Sensation Seeking (SS) Scale scores to undergraduates' ratings of their past/present and expected future participation in four leisure activities that usually involve betting money. Subjects completed McKeachnie's (1975) Leisure Activities Blank (LAB), which included the gambling items, and Zuckerman's (1979) SS Scale. Men reported significantly more past/present leisure gambling than women; gender differences were insignificant in ratings of expected future gambling. No significant differences in reported past/present gambling related to any SS scale score. However, expected future gambling ratings were associated with scores on two SS subscales: Disinhibition (DIS) and Boredom Susceptibility (BS). Both male and female subjects with high DIS scores rated the frequency of expected future gambling higher than did subjects with low DIS scores. High BS scores were associated with high ratings of expected future gambling in the data for women subjects only. These results suggest that personality factors, among them SS, are more influential than early experience or sex-role socialization in determining a young adult's interest in gambling.     

Analytical uses of Kalman filtering in econometrics — A survey

This paper surveys the different uses of Kalman filtering in the estimation of statistical (econometric) models. The Kalman filter will be portrayed as (i) a natural generalization of exponential smoothing with a time-dependent smoothing factor, (ii) a recursive estimation technique for a variety of econometric models amenable to a state space formulation in particular for econometric models with time varying coefficients (iii) an instrument for the recursive calculation of the likelihood of the (constant) state space coefficients (iv) a means of helping to implement the scoring⁻ and EM-method for iteratively maximizing this likelihood (v) an analytical tool in asymptotic estimation theory. The concluding section points to the importance of Kalman filtering for alternatives to maximum⁻ likelihood estimation of state space parameters.     

In memoriam Gerburg Treusch-Dieter (1939–2006)

Ohne Zusammenfassung     

<Emphasis Type="Italic">Jürgen H.P. Hoffmeyer-Zlotnik</Emphasis> und <Emphasis Type="Italic">Christof Wolf:</Emphasis> Advances in cross-national comparison. A European working book for demographic and socio-economic variables

Ohne Zusammenfassung

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Jürgen H.P. Hoffmeyer-Zlotnik und Christof Wolf: Advances in cross-national comparison. A European working book for demographic and socio-economic variables New York/Boston/Dordrecht/London/Moscow: Kluwer academic/plenum publishers 2003. 413 Seiten. ISBN 0-306-47731-9. Preis: € 153,-