Patricia A. Hageman

Age and gender effects on postural control measures

OBJECTIVE Identifying age-related changes in the postural control system is an important first step towards understanding the risk for falls in older adults. The purpose of this study was to determine whether age or gender had any effects on six relatively new postural control measures. DESIGN Cross-sectional, 2 x 2 factorial design, representing two ages (younger [20 to 35 years], and older [60 to 75 years]) and both sexes. SETTING University campus. PARTICIPANTS Twenty-four community dwelling healthy adults (12 women, 12 men) participated in each of the younger and older groups. MAIN OUTCOME MEASURES Outcome measures included five force platform measures and functional reach (cm). The force platform measures, obtained using the Balance Master system, included movement time and path length to targets, and sway area under conditions of eyes open, eyes closed, and with visual feedback. RESULTS Although gender was not significant for any outcome measure, age was significant in all six outcome measures. Older adults demonstrated larger areas of sway regardless of condition (eyes open, eyes closed or with visual feedback). Older adults had longer movement times, longer path lengths, and shorter distances of functional reach when compared with younger adults. CONCLUSIONS The results suggest that the measures studied are sensitive to age-related changes in healthy elderly.

Nonlinear dynamics indicates aging affects variability during gait

OBJECTIVE To investigate the nature of variability present in time series generated from gait parameters of two different age groups via a nonlinear analysis. DESIGN Measures of nonlinear dynamics were used to compare kinematic parameters between elderly and young females. BACKGROUND Aging may lead to changes in motor variability during walking, which may explain the large incidence of falls in the elderly. METHODS Twenty females, 10 younger (20-37 yr) and 10 older (71-79 yr) walked on a treadmill for 30 consecutive gait cycles. Time series from selected kinematic parameters of the right lower extremity were analyzed using nonlinear dynamics. The largest Lyapunov exponent and the correlation dimension of all time series, and the largest Lyapunov exponent of the original time series surrogated were calculated. Standard deviations and coefficient of variations were also calculated for selected discrete points from each gait cycle. Independent t-tests were used for statistical comparisons. RESULTS The Lyapunov exponents were found to be significantly different from their surrogate counterparts. This indicates that the fluctuations observed in the time series may reflect deterministic processes by the neuromuscular system. The elderly exhibited significantly larger Lyapunov exponents and correlation dimensions for all parameters evaluated indicating local instability. The linear measures indicated that the elderly demonstrated significantly higher variability. CONCLUSIONS The nonlinear analysis revealed that fluctuations in the time series of certain gait parameters are not random but display a deterministic behavior. This behavior may degrade with physiologic aging resulting in local instability. RELEVANCE Elderly show increased local instability or inability to compensate to the natural stride-to-stride variations present during locomotion. We hypothesized that this may be the one of the reasons for the increases in falling due to aging. Future efforts should attempt to evaluate this hypothesis by making comparisons to pathological subjects (i.e. elderly fallers), and examine the sensitivity and specificity of the nonlinear methods used in this study to aid clinical assessment.

Comparison of Gait of Young Women and Elderly Women

The purpose of our study was to describe and compare free-speed gait patterns of healthy young women with healthy elderly women. The evaluation was completed with high-speed cinematography using synchronized front and side views of 26 healthy volunteers. One group was composed of 13 subjects 20 to 35 years of age, and the other group was composed of 13 subjects 60 to 84 years of age. Each subject participated in one test session consisting of three filmed trials of free-speed ambulation down a 14-m walkway. The processed film was analyzed for 10 gait characteristics. Differences in gait characteristics between the two groups were examined using a correlated t test (p less than .01). The elderly women demonstrated significantly smaller values of step length, stride length, ankle range of motion, pelvic obliquity, and velocity when compared with the younger women. The results of our study suggest that the physical therapist should not establish similar expectations for young women and elderly women during gait rehabilitation.

Tailored versus standard internet-delivered interventions to promote physical activity in older women.

Purpose: While substantial evidence demonstrates physical activity is effective at reducing risk for cardiovascular and other diseases, the percentage of older women participating in regular activity is low. The Internet offers an alternative method for delivery of a primary prevention intervention. This preliminary study examined the feasibility and effectiveness of using the Internet to deliver behavior change interventions for promoting physical activity in women ages 50‐69 years. Methods: Thirty‐one healthy women (56.1 ± 4.9 years) were randomly assigned to either tailored or standard newsletter groups. Both groups received 3 Internet‐delivered newsletters at baseline, 1 month, and 2 months. Behavioral markers and biomarkers were measured at baseline and postintervention. Post‐testing occurred at 3 months (1 month after delivery of the third newsletter). Results: Repeated measures ANOVAs revealed improvement in measures of flexibility and perceived barriers to exercise for both groups. For the standard group, improvement occurred in % body fat while VO2max declined. Women indicated the newsletters were helpful in influencing behavior change. Conclusion: Internet‐delivered newsletters appeared feasible and promising for favorably influencing perceptions about barriers to physical activity in these women. Selfreported physical activity did not increase although selected biomarkers did improve. Whether tailored or standard messaging was more effective was inconclusive.

A preliminary study on the reliability of physical performance measures in older day-care center clients with dementia

BACKGROUND Decline in physical functional ability is an intrinsic component of the dementia syndrome. Reductions in muscle mass and strength represent a major factor in the loss of functional ability Although resistance exercise has been studied as a method for maintaining/recovering function in populations of frail older adults, people with dementia have been systematically excluded because of uncertainty about the reliability of outcome measurements. OBJECTIVE The purpose of this study was to determine the test-retest reliability of a battery of established performance-based measures of strength and function among subjects with dementia. SETTING A hospital-affiliated adult day-care facility. SUBJECTS Twelve of 28 older subjects with dementia of various etiologies were available for two assessments prior to implementation of a resistance-exercise intervention. METHODS Subjects underwent an assessment of lower extremity strength and physical function consisting of two recorded trials of bilateral isometric strength of the knee extensor, hip flexor, and dorsiflexor muscles, as well as hand grip strength; repeated chair stands, evaluation of usual- and maximal safe-gait speed over a 6-m course, and the Timed-Up-and-Go Test. The entire assessment was repeated approximately 1 week later. An average of the trials for each measurement was computed for each of the two assessment periods, and intraclass correlation coefficients (ICCs) for these paired measurements were estimated using STATA. RESULTS ICCs ranged from .56 for left iliopsoas to .77 for left dorsiflexors among the strength measures whereas measures of function ranged from .80 for number of steps in usual gait to .95 for time of fast gait. CONCLUSIONS Performance-based measures of strength and function can be reliably assessed in older people with dementia, although measures of function appear to be more reliable than measures of strength.

Determinants of Older Rural Women’s Activity and Eating

This research examined the relationship of cognitive-perceptual determinants from the Health Promotion Model to physical activity and healthy eating at baseline of a clinical trial among rural women aged 50 to 69. Two multivariate regression analyses with canonical correlation (N = 179) each yielded one interpretable canonical variate that explained similar amounts of variance (21.7% and 22.5%) in sets of activity and eating variables. In both analyses, the determinants set is a linear combination of all four cognitive-perceptual constructs from the model (perceived self-efficacy, benefits, barriers, interpersonal influences). The activity behavior set included caloric expenditure, VO2max, and stretching and strengthening activity, whereas the eating behavior set included daily percentage of calories from fat and servings of fruits and vegetables, meat, and whole grains. As predicted by theory, greater self-efficacy, benefits and interpersonal support, and fewer barriers are associated with desirable healthy lifestyle behaviors.

Clinical trial of tailored activity and eating newsletters with older rural women

Background: Unhealthy diet and lack of physical activity increase rural midlife and older womens risk of chronic diseases and premature death, and they are behind urban residents in meeting Healthy People 2010 objectives. Objectives: The objective of this study was to compare a tailored intervention based on the Health Promotion Model with a generic intervention to increase physical activity and healthy eating among rural women. Methods: In a randomized-by-site, community-based, controlled, clinical trial, Wellness for Women, 225 women aged 50 to 69 years were recruited in two similar rural areas. Over 12 months, women received by mail either 18 generic newsletters or 18 newsletters computer tailored on Health Promotion Model behavior-specific cognitions (benefits, barriers, self-efficacy, and interpersonal support), activity, and eating. Outcomes at 6 and 12 months included behavioral markers and biomarkers of physical activity and eating. Data were analyzed by repeated-measures analysis of variance and chi-square tests (&agr; < .05). Results: Both groups significantly increased stretching and strengthening exercise and fruit and vegetable servings and decreased percentage of calories from fat, whereas only the tailored group increased moderate or greater intensity activity and decreased percentage of calories from saturated fat from baseline to 6 months. Both groups increased stretching and strengthening exercise, whereas only the tailored group increased moderate or greater intensity activity and fruit and vegetable servings and decreased percentage of calories from fat from baseline to 12 months. Both groups had several changes in biomarkers over the study. A higher proportion of women receiving tailored newsletters met Healthy People 2010 criteria for moderate or greater intensity activity, fruit and vegetable servings, and percentage of calories from fat at 12 months. Discussion: Mailed computer-tailored and generic print newsletters facilitated the adoption of change in both activity and eating over 6 months. Tailored newsletters were more efficacious in facilitating change over 12 months.

Comparison of Gait Patterns between Young and Elderly Women: An Examination of Coordination:

This study investigated intralimb coordination during walking in young and elderly women using the theoretical model of dynamical systems. 20 women, 10 Young (M age = 24.6 yr., SD = 3.2 yr.) and 10 Elderly (M age = 73.7 yr., SD = 4.9 yr.), were videotaped during free speed gait and gait perturbed by an ankle weight. Two parameters, one describing the phasing relationship between segments (mean absolute relative phase) and the other the variability of this relationship (deviation in phase), were calculated from the kinematics. Two-way analysis of variance (age and weight) with repeated measures on weight indicated that during the braking period the weight increased the mean absolute relative phase between the shank and the thigh and decreased it between the foot and the shank. The Elderly women had significant smaller values for the mean absolute relative phase between the shank and the thigh during the braking period. For the same period, deviation in phase increased for the segmental relationship between the shank and the thigh. The findings suggest that changes in intralimb coordination take place with asymmetrical weighting and the aging process. These changes are most clearly present during the braking period.

Feasibility of Internet-delivered weight loss interventions among rural women ages 50-69.

Purpose: The increased availability and use of the Internet by midlife and older women who seek health information may provide an innovative method for delivering weight loss interventions. This preliminary study examined the feasibility and efficacy of web‐based interventions for promoting weight loss among rural overweight and obese women ages 50‐69 (M =55.5 ± 4.9) over a 3‐month period. Methods: Twenty‐one Caucasian women with body mass index of 28‐34.5 (M = 30.69 ± 2.58) were randomly assigned to either a Web site only or Web site augmented with a peer‐led support group. The Web site included recommended approaches to healthy eating and activity, weekly newsletters, and other resources. Body weight, eating, and activity measures were assessed at baseline and postintervention. Data analysis included 2‐way repeated measures ANOVAs with effect sizes reported as appropriate for a pilot study. Results: Sixteen women (76.2%) completed the study; 14 lost from 2% to 10% of their body weight, and 2 gained 2% of their weight. Large effect sizes were found over time for body weight, estimated VO2max, and percentage of calories from fat. For time by group interaction, large effect sizes favoring the Web site plus peer‐led support group were found for body weight, waist circumference, percent body fat, whole grain servings, and both systolic and diastolic blood pressure. Process evaluations indicated that 85.7% of women accessed the Web site weekly. There were a total of 305 hits in the Web site only group versus 658 hits in the peer‐led support groups. Conclusions: Internet delivered interventions appeared feasible for these rural women with weight loss and improvement in selected eating and activity measures after 3 months.

Maintenance of activity and eating change after a clinical trial of tailored newsletters with older rural women.

Background:In the Wellness for Women Project, a randomized-by-site 1-year controlled clinical trial, the efficacy of generic newsletters and newsletters tailored on Health Promotion Model behavior-specific cognitions, eating behavior, and activity behavior were compared among 225 women aged 50 to 69 years. Objectives:The purpose of this study was to compare the maintenance of change in healthy eating and physical activity over the 12 months following the tailored versus generic mailed newsletter intervention. Methods:Outcomes at 18 and 24 months included behavioral markers and biomarkers of physical activity and eating. Data were analyzed using the multivariate approach to repeated measures analysis of variance and generalized estimating equations (α <.05). Results:At 18 months, the tailored group maintained levels of all eating and activity behaviors, whereas the generic group maintained levels of fruit and vegetable servings, a moderate or greater activity, stretching exercise, lower body strength and flexibility but increased saturated fat intake and declined in weekly strength exercise and cardiorespiratory fitness. At 24 months, both groups maintained or returned to 12-month levels of all eating behaviors,moderate or greater activity, stretching exercise, and flexibility but declined in cardiorespiratory fitness; the tailored group maintained levels of strength exercise and lower body strength, whereas the generic group decreased in both. A greater proportion of women who received tailored newsletters continued to achieve most Healthy People 2010 criteria for eating and activity. Discussion:Mailed tailored print newsletters were more efficacious than generic newsletters in facilitating maintenance of change in eating and activity for 6 months postintervention. Both tailored and generic newsletters facilitated the maintenance of change in eating behaviors and in moderate or greater physical activity and stretching exercise, whereas tailored newsletters were more efficacious in maintaining change in strength exercise for 12 months postintervention.