Biomedical subjects

Pertti Era

Publications and source records attributed to Pertti Era.

16 recordsLinked to original sources

PubMed2006

Genetic and environmental contribution to postural balance of older women in single and dual task situations.

The purpose of the present study was to examine the effect of a second task on postural balance and to determine the role of genetic influences on postural balance when dual tasking among 206 monozygotic and 227 dizygotic female twins, aged 63-76 years. Balance was measured as medio-lateral and antero-posterior velocity of the centre of pressure (COP) (mm/s) and velocity moment (mm(2)/s) while standing on a force platform. Doing an arithmetic task increased movement of the COP while the hand motor task had no effect on movement of the COP. The genetic contribution to balance in the single task situation was minor (14%, 95% confidence interval, CI: 11-35%) whereas in the dual task situation it was moderate (28%, 95% CI: 0.02-42%). The finding can be explained in the light of the underlying phenotypes of dual tasking, such as cognitive processing that is found to be under considerable genetically controlled even in old age. Moreover, the present study supports previous studies suggesting that, especially among older people, when simultaneously maintaining balance and performing another cognitively demanding task, additional central processing is recruited.

Aged↗

PubMed2006

Genetic factors and susceptibility to falls in older women.

OBJECTIVES: To determine whether genetic influences account for individual differences in susceptibility to falls in older women. DESIGN: Prospective twin cohort study. SETTING: Research laboratory and residential environment. PARTICIPANTS: Ninety-nine monozygotic (MZ) and 114 dizygotic (DZ) female twin pairs aged 63 to 76 from the Finnish Twin Cohort study. MEASUREMENTS: The participants recorded their falls on a calendar for an average+/-standard deviation of 344+/-41 days. Reported falls were verified via telephone interview, and circumstances, causes, and consequences of the fall were asked about. RESULTS: The total number of falls was 434, of which 188 were injurious; 91 participants had two or more falls. Casewise concordance was 0.61 (95% confidence interval (CI)=0.49-0.72) for MZ twins and 0.49 (95% CI=0.37-0.62) for DZ twins for at least one fall, 0.38 (95% CI=0.23-0.53) for MZ and 0.33 (95% CI=0.17-0.50) for DZ twins for at least one injurious fall, and 0.43 (95% CI=0.26-0.60) for MZ and 0.36 (95% CI=0.17-0.55) for DZ twins for recurrent falls. On average, the proportion of familial influences accounting for the individual differences in susceptibility to at least one fall was 30% and to recurrent falls was 40%; nongenetic familial and nonfamilial factors alone accounted for susceptibility to at least one injurious fall. CONCLUSION: In community-dwelling older women, familial factors underlie the risk of falling but not the risk of injurious falls.

Accidental Falls↗

PubMed2006

Force platform measurements as predictors of falls among older people - a review.

BACKGROUND: Poor postural balance is one of the major risk factors for falling. A great number of reports have analyzed the risk factors and predictors of falls but the results have for the most part been unclear and partly contradictory. Objective data on these matters are thus urgently needed. The force platform technique has widely been used as a tool to assess balance. However, the ability of force platform measures to predict falls remains unknown. OBJECTIVE: The purpose of this systematic review was to extract and critically review the findings of prospective studies where force platform measurements have been used as predictors of falls among elderly populations. METHODS: The study was done as a systematic literature review. PubMed, the Cochrane Central Register of Controlled Trials, and CINAHL databases from 1950 to April 2005 were used. The review includes prospective follow-up studies using the force platform as a tool to measure postural balance. RESULTS: Nine original prospective studies were included in the final analyses. In five studies fall-related outcomes were associated with some force platform measures and in the remaining four studies associations were not found. For the various parameters derived on the basis of the force platform data, the mean speed of the mediolateral (ML) movement of the center of pressure (COP) during normal standing with the eyes open and closed, the mean amplitude of the ML movement of the COP with the eyes open and closed, and the root-mean-square value of the ML displacement of COP were the indicators that showed significant associations with future falls. Measures related to dynamic posturography (moving platforms) were not predictive of falls. CONCLUSION: Despite a wide search only a few prospective follow-up studies using the force platform technique to measure postural balance and a reliable registration of subsequent falls were found. The results suggest that certain aspects of force platform data may have predictive value for subsequent falls, especially various indicators of the lateral control of posture. However, the small number of studies available makes it difficult to draw definitive conclusions.

Accidental Falls↗

PubMed2005

Hearing among 75-year-old people in three Nordic localities: a comparative study.

The aim of this study was to compare auditory functions and to analyse the prevalence of hearing impairment and the relationship of self-reported hearing disability with audiometric test results among 75-year-old people in three Nordic localities. The representative samples came from Glostrup, Denmark (n = 571), Göteborg, Sweden (n =450), and Jyväskylä, Finland (n =388). The median pure-tone thresholds were rather similar in all three populations. The prevalence of moderate hearing impairment varied between 26% and 34% in men, and between 17% and 23% in women. The corresponding figures in the prevalence of self-reported hearing difficulties were 41%-57%, and 28%-37%. The self-reported difficulties were broadly in accordance with the audiometric test results, but there also were individuals with conflicting results. It is concluded that the prevalence of hearing impairment in the three Nordic localities is fairly similar. To assess hearing disorders in elderly people, both audiometry and self-report data are needed.

Aged↗

PubMed2005

Contribution of genetic and environmental factors to individual differences in maximal walking speed with and without second task in older women.

BACKGROUND: Among older people, distraction while walking may increase the risk of falls. Factors underlying individual differences in dual tasking are not fully understood. Our aim was to study the effect of a second task on maximal walking speed and to examine whether individual differences in walking speed measured with and without a second task are accounted for by genetic and environmental influences shared across tasks or specific to each task. METHODS: The data were collected from the 101 monozygotic and 116 dizygotic twin pairs aged 63-76 years recruited from the Finnish Twin Cohort. Maximal walking speed (MWS) over 10 m was measured on a laboratory corridor and timed with photocells. The test was repeated while subjects performed, first, a manual task (MWSmanual) and, second, a verbal task (MWSverbal). RESULTS: Mean walking speed without a simultaneous task was 1.72 m/s (standard deviation [SD] 0.33), with a manual task it was 1.52 m/s (SD 0.26), and with a verbal task it was 1.36 m/s (SD 0.27). Multivariate genetic analysis showed that an additive genetic factor in common accounted for 17% of individual differences in MWS, 19% in MWSmanual, and 12% in MWSverbal. In addition, MWSverbal had a genetic factor specific to it accounting for 10% of the variance. Shared environmental influences, common to all three traits, accounted for 39%, 27%, and 21% of the individual differences, respectively. CONCLUSION: Approximately half of the individual differences in walking with or without another task were accounted for by genetic and nongenetic familial effects in common, and the rest of the variation was accounted for by unique environmental factors in common and factors specific to walking tests.

Aged↗

PubMed2004

Postural balance and health-related factors in middle-aged and older women with injurious falls and non-fallers.

BACKGROUND AND AIMS: Older fallers aged over 70 years have shown impaired balance abilities, but it is unclear if impairment in balance control can be detected among fallers who are in their 50's and 60's. The aim of this study was to analyze possible differences in balance control and other health-related factors between female fallers and non-fallers aged 50-68 years. METHODS: Women 50-68 years of age (N=40) who had fallen outside and needed medical attention were recruited through a larger fall accident study. Non-fallers (N=97) were women representing the same age group who had not fallen during the preceding 12 months. A battery of standing force platform balance tests were administered together with an interview on health status, use of medication, dizziness, vision, hearing, and physical activity. RESULTS: Significant differences were not found between women with injurious falls and non-fallers in the various balance tests. In the younger age group (50-58 years), chronic illnesses, use of medication, dizziness, and self-reported problems with vision and hearing were more common in fallers than in non-fallers. CONCLUSIONS: Our results suggest that, in active and independent women aged 50-68 years, it is not possible to use standing force platform balance tests to detect differences between fallers and non-fallers. However, younger women (50-58 years) with injurious falls reported more health-related problems than other groups, a fact which should be taken into consideration to prevent further development of fall-related problems.

Accidental Falls↗

PubMed2004

Changes in hearing in 80-year-old people: a 10-year follow-up study.

The aims of this prospective 10-year longitudinal population study were to report changes in hearing in people aged 80 years at baseline, and to assess such changes by comparing results from both cross-sectional and longitudinal analyses. The study population comprised all residents of the city of Jyväskylä born in 1910 (n = 291). The subjects' hearing was tested on three occasions at 5-year intervals with the use of pure-tone audiometry, speech audiometry, and self-report on hearing difficulties. The results showed a significant deterioration in hearing sensitivity in both the longitudinal and cross-sectional assessments over the 10-year follow-up. However, the change in self-assessed hearing difficulties was not significant. Hearing aids were not used by over 75%, of those who had moderate hearing impairment. Self-assessed hearing difficulties at baseline were associated with increased mortality. Hearing deterioration in elderly people and their low level of use of hearing aids deserve closer attention in the healthcare system.

Age Factors↗

PubMed2004

Relationships between standing balance and symmetry measurements in patients following recent strokes (3 weeks or less) or older strokes (6 months or more).

BACKGROUND AND PURPOSE: The Functional Standing Balance (FSB) Scale was designed to obtain measurements of standing balance and to identify the problems typically faced by people with stroke. The purpose of this study was to investigate the validity of measurements obtained with the FSB Scale for use in the acute and chronic phases of stroke by comparing the measurements obtained with the FSB Scale with those obtained for postural sway and lateral symmetry by use of a force platform. SUBJECTS AND METHODS: Measurements were obtained for 26 people with recent strokes (ie, strokes within 3 weeks of data collection) and for 28 people with long-standing strokes (ie, strokes of 6 months' duration or older). The FSB Scale consists of 3 components: weight distribution, balance without movement, and balance with movement. Measurements of balance performance were compared with measurements of anteroposterior and lateral sway velocity obtained on a force platform. The weight distribution on 2 digital scales was compared with the lateral symmetry measured on the force platform. RESULTS: The highest correlations were found between the FSB Scale balance measurements and the measurements of anteroposterior sway velocity obtained on the force platform with feet apart and eyes open. The correlations (r) were -.68 and -.67 for the group with recent strokes and -.74 and -.91 for the group with long-standing strokes. The correlations (r) between weight distribution measured on the digital scales and lateral symmetry measured on the force platform were.44 for the group with recent strokes and.52 for the group with long-standing strokes. DISCUSSION AND CONCLUSION: The subjects whose results on the FSB Scale were poor had higher sway velocities on the force platform than the subjects whose results on the FSB Scale were good. The results of this study suggest that the FSB Scale provides the same kind of information as that obtained for sway velocity and lateral symmetry as measured with the use of force platforms in both patients with recent strokes and patients with long-standing strokes.

Aged↗

PubMed2003

Contribution of genetic and environmental effects to postural balance in older female twins.

The aim of the present study was to determine the relative roles of genetic and environmental influences on postural balance in older women. The participants were 97 monozygotic (MZ) and 102 dizygotic (DZ) female twins, aged 64-76 yr. Postural sway was measured during side-by-side stance with eyes open and eyes closed, and during semitandem stance with eyes open on a force platform. Sway data were condensed into four first-order and one second-order latent factors. The second-order factor, named balance, incorporates sway data from multiple tests and thus best describes the phenotype of postural balance. The contribution of genetic and environmental influences on the variability of the latent factors was assessed by using structural equation modeling. Additive genetic influences accounted for 35% and shared environmental influences accounted for 24% of the total variance in the balance factor. In the present study, postural balance in older women had a moderate genetic component. Genetic influences on postural balance may be mediated through gene variation in the systems that control posture. The finding that individual environmental influences accounted for almost one-half of the variance in postural balance points to the potential of targeted interventions to maintain and improve balance control in older persons.

Aged↗

PubMed2003

Multidimensional health assessment of 75- and 80-year-old men and women: a five-year prospective study.

BACKGROUND AND AIMS: There are no earlier reports of regular multidimensional health check programs in elderly people. The aim of this study was to establish the number and type of previously unrecognized health conditions in two cohorts of elderly people examined twice during a 5-year period, and to determine how these conditions were subsequently evaluated and treated. METHODS: This population-based study, carried out at a university research center in Finland, consisted of a multidimensional and multiphased health assessment including interviews, health questionnaires and medical examinations and tests, and follow-up of subsequent examinations and treatment. Participants were all 75- (N = 388) and 80-year-old (N = 291) people residing in the city of Jyväskylä in 1989 and 1990 respectively. RESULTS: A total of 780 health assessments were carried out, 500 at baseline and 280 five years later. Large numbers of previously unrecognized conditions were found on both occasions, ranging from tumors to impacted cerumen. At baseline, 180 persons (36% of those assessed) were referred for further examinations or treatment, at follow-up 127 (45%). Half of the referred persons received treatment, 13-39% were evaluated but not treated. For 12-33%, no information was obtained on post-hoc events. CONCLUSIONS: Comprehensive health assessments in older people reveal a large number of previously unrecognized conditions that require further examination and/or treatment, suggesting the need for systematic and regular assessments of health and functional capacity.

Aged↗

PubMed2003

Evaluating the interdependence of aging-related changes in visual and auditory acuity, balance, and cognitive functioning.

High proportions of shared age-related variance are found among measures of perceptual acuity, balance, muscle strength, and cognitive capabilities in age-heterogeneous, cross-sectional studies. Reliance on cross-sectional studies is problematic, however, because associations may arise from age-related mean trends. Narrow age-cohort samples provide an alternative basis for testing hypotheses regarding associations among rates of change. Cross-domain associations were evaluated in combined 75-year-old cohort samples from Denmark, Finland, and Sweden. In general, no consistent associations were found across sensory, balance, strength, and cognitive domains. These findings indicate that the effects of aging on sensory acuity, balance, and cognitive functioning are likely to be largely independent, multidimensional, and complex at the level of the individual.

Age Factors↗

PubMed2003

The effects of augmented kinematic feedback on motor skill learning in rifle shooting.

In this study, we examined the effects of augmented kinematic knowledge of performance (KP) on shooting performance and learning. Knowledge of performance described the aiming trajectory of the rifle barrel. The effects of knowledge of performance were evaluated in terms of shooting accuracy (shooting score), variability of the shooting score (root mean square error) and rifle stability (x- and y-deviation of rifle movement). The participants (n = 40) were randomly assigned to one of four groups: no-KP, 50% KP, 100% KP and a control group. The three experimental groups performed 480 shots during a 4 week acquisition phase in which feedback was provided. No-feedback retention tests were administered at 2 and 10 days after acquisition. There were no differences between groups during acquisition. In the 2 day retention test, the mean shooting score of the group receiving 100% knowledge of performance was significantly higher than that of the other groups. Furthermore, variability in shooting score for the 100% KP group was lower than that for the 50% KP and control groups. No significant differences were found in rifle stability between the experimental groups. In summary, a high frequency of kinematic knowledge of performance improved shooting accuracy, but the effect appeared to be temporal, disappearing in the 10 day retention test. Given that a parallel effect was not found in rifle stability, future research should focus on examining the reasons for this improvement in shooting score.

Adult↗

PubMed2002

Postural balance in elderly people: changes over a five-year follow-up and its predictive value for survival.

Postural balance in three test conditions (normal standing with eyes open, normal standing with eyes closed, and tandem standing with eyes open) was measured in samples of 75-year-old men and women (N=757) living in three Nordic localities (Glostrup in Denmark, Göteborg in Sweden, and Jyväskylä in Finland). The subjects were re-tested five years later when they had reached the age of 80 years (N=434). The results showed a highly significant longitudinal decline in balancing abilities in all localities and in both sexes. The longitudinal change was larger than suggested by cross-sectional comparisons. On both occasions women showed better results in the balance tests than men in all three localities. Inter-locality differences observed at baseline (somewhat poorer performance among the subjects from Göteborg) largely remained during the follow-up. The simplest balance test, normal standing with eyes open, was also a significant predictor for survival over the 5-year follow-up: the results at baseline were poorer in those subjects who died during the follow-up than in the survivors. It is concluded that postural balance deteriorates markedly from 75 to 80 years of age; at high ages a poor performance in balance tests may also indicate below-average survival.

Aged↗

PubMed2002

The incidence of mobility restrictions among elderly people in two Nordic localities. A five-year follow-up.

The aim of this study was to investigate the incidence of limitations in self-reported mobility as well as the decline in measured walking speed and stair-mounting ability over five years among men and women aged 75 at baseline in two Nordic localities. Another purpose was to analyze the relationship and its consistency over time between self-reports and performance-based measures in the decline of mobility. Identical Interviews and performance tests were carried out in Jyäskylä, Finland (N=244) and Glostrup, Denmark (N=275) at baseline and five years later. The subjects were asked about their ability to manage with transferring from chair or bed, walking indoors and outdoors and climbing stairs. The occurrence of new limitations in these tasks was analyzed among those who did not report limitations in the same task at baseline. Maximal walking speed and step-mounting height were measured in the laboratory. The decline in walking speed below 1.2 m/s and stair-mounting height below 30 cm was analyzed among those whose results were, initially, above these limits. Most frequently, new limitations occurred in walking outdoors and in climbing stairs (44-60%). Walking speed and stair-mounting ability deteriorated below the thresholds mentioned in 4-36% of the participants, depending on gender and locality. There were only minor differences between the two Nordic localities in the decline in mobility functions. A substantial proportion of those whose performance had declined had developed limitations in self-reported mobility as well. However, the relationship between different methods of measurement was not straightforward. This indicates that multiple approaches are needed to obtain thorough knowledge about mobility and its decline among elderly people.

Activities of Daily Living↗

PubMed1999

Brain Slow Potentials and Postural Sway Behavior During Sharpshooting Performance.

In the present study, the relation of preparatory brain slow potentials (SPs) to postural body sway during sharpshooting performance was examined. SPs from frontal, left-central, and right-central areas were recorded from 6 elite and 6 non-elite sharpshooters during a realistic simulated shooting task. A force platform technique was used in the recording of postural sway. The results showed that body sway, as indexed by sway amplitude and mean velocity, was associated with the concomitant SP changes. That relationship was dependent on the shooter's expertise level, however. The main finding among the elite shooters was that the reduced amplitude of body sway coincided with reduced frontal positivity, whereas in the non-elite shooters, the amplitude of sway and the mean sway velocity in the anteroposterior direction were typically accompanied by the lateralization of central negativity. Those findings offer some new insights for evaluating the functional significance of preparatory brain SPs associated with psychomotor processing in sharpshooting. The results from the present study also have implications for the understanding of the postural strategies employed by shooters of different expertise levels.

Journal Article↗

PubMedDate not supplied

Fall incidence in frail older women after individualized visual feedback-based balance training.

BACKGROUND: The knowledge concerning balance training actually lowering fall rates among frail older persons is limited. OBJECTIVE: The aim of this study was to examine the effects of a 4-week individualized visual feedback-based balance training on the fall incidence during 1-year follow-up among frail older women living in residential care. METHODS: Twenty-seven older women from 2 residential care homes were randomized into exercise (n = 20) and control (n = 7) groups. Balance measurements were carried out before and after a 4-week training period and falls were monitored by monthly diaries for 1 year. An interview about fear of falling and physical activity was completed before and after the intervention and after the 1-year follow-up. RESULTS: A positive effect of balance training on fall incidence was found. A dynamic Poisson regression model showed that during the follow-up the monthly risk of falling was decreased in the exercise group compared to controls (risk ratio 0.398, 95% CI 0.174-0.911, p = 0.029). In addition, the exercise group reported a reduced fear of falling and increased physical activity after a training period but these changes declined during the follow-up period. CONCLUSION: Individualized visual feedback-based balance training was shown to be a promising method for fall prevention among frail older women. High compliance (97.5%) with the training program showed that carefully targeted training programs can be carried out among older people with health limitations.

Accidental Falls↗