Postural Balance and Self-Reported Exercise in Older · PDF filePostural Balance and...

ADAPTED PHYSICAL ACTIVITY QUARTERLY, 2000,17, 69-77 0 2000 Human Kinetics Publishers, Inc.

Postural Balance and Self-Reported Exercise in Older Adults

Suzanne C. Hoeppner Northern Illinois University

James H. Rimmer University of Illinois at Chicago

The purpose of this study was to determine if self-reported exercise status (exercise, nonexercise) and ambulatory status (aid, no aid) discriminate between balance performance and balance self-efficacy of older adults, ages 65 to 95 years. Participants were 14 males and 46 females in a retirement home that contained a supervised fitness center. An activities-specific balance confidence scale and three balance performance tests yielded data. Data from males and females were combined because independent t tests revealed no significant gender differences. The Mann Whitney U test revealed that (a) exercisers (M age = 83.4) scored significantly higher than nonexercisers (M age = 83.7) on all measures, and (b) nonaid users (M age = 83.5) scored significantly higher than aid users (M age = 83.7). Findings indicate that regular exercise (at least 30 min per day, 3 days per week) and ambulation without a cane or walker are descriptors of older adults with good balance performance and high balance self-efficacy.

Physical activity is a key factor in preserving physical independence in older adults (American College of Sports Medicine, 1998). A sedentary lifestyle hastens the decline in physical mobility and function and predisposes older adults to a higher incidence of chronic disease and disability (Sharpe et al., 1997). Despite the role that exercise plays in maintaining functional mobility in older adulthood, activity levels rapidly decline with age, especially in individuals who are in their 80s and 90s (Sharpe et al., 1997).

One area of motor performance that is critical for maintaining functional mobility and physical independence is balance (Lewis & Bottomley, 1994). Bal- ance is required for maintaining body position, remaining stable while moving from one position to another, performing activities of daily living, and moving freely in the environment (Berg, Maki, Williams, Holliday, & Wood-Dauphinee,

Suzanne C. Hoeppner was at Northern Illinois University during the time of this study. She now lives in Florida. James H. Rimmer is with the Department of Disability and Human Development at the University of Illinois, Chicago, IL 60608-6904.

70 Hoeppner and Rimmer

1992). Impairments in balance lead to unwanted consequences, including a loss of movement and independence (Clark, 1996), fear of falling (Gill, Kelley, Williams, & Martin, 1994), falls resulting in fractures (Tinetti, Williams, & Mayewski, 1986), and a lowered quality of life (Sauvage et al., 1992). The fear of falling may be associated with the "postfall syndrome," which is believed to lead to activity re- striction and loss of independence (Myers et al., 1996). Self-imposed activity re- striction can impair balance because of its negative impact on coordination, flexibility, muscle strength, and endurance (Myers et al., 1996).

For those in their 80s and 90s, protection from fall-related injury is a major concern to the individual, family members, caregivers, and health care providers (Lueckenotte, 1996). Fear of falling may be a pervasive problem among older adults, even among those who have never experienced a fall. This fear may lead to a severe loss in mobility and function (Powell & Myers, 1995).

A major contributor to falls in older persons is diminished functioning of a number of physiological systems, in particular, the sensory motor system, which contributes to balance and stability (Woolacott & Shumway-Cook, 1990). While a number of studies demonstrate improved strength and aerobic power in older adults (American College of Sports Medicine, 1998), research on the effects of exercise on postural balance is less clear (Alexander, 1994). Training programs for older adults, thus far, have not achieved consistently positive gains in the ability to maintain or improve balance (Alexander, 1994; Lord, Ward, Williams, & Strudwick, 1995).

One way to address the association between postural balance and exercise in older adults is to conduct prospective studies with individuals who are not involved in an exercise program. Several obstacles, however, occur in this type of research with an older population. In particular, it is difficult to (a) find enough healthy volunteers who are currently not exercising but are willing to start a program in later adulthood; (b) obtain approval from physicians and institutional review boards to conduct studies with older individuals; (c) identify volunteers who are willing to adhere to an exercise program over several months; and (d) secure funds to pay for the costs associated with screening clients for medical approval to participate in an exercise program (e.g., blood analysis, exercise stress test).

Understanding the potential impact of habitual exercise in maintaining postural balance in octogenarians and nonagenarians, the fastest growing segment of the population over age 65 (Campion, 1994), is important (Meldrum & Finn, 1993). To date, most studies on postural balance have been conducted on persons under the age of 80 (Alexander, 1994). The least intrusive way to assess the benefits of exercise on postural balance in older adults is to compare intact groups of exercisers and nonexercisers and to identify, through self-report and safe balance performance measures, the unique and important dimensions of physical activity (Winograd et al., 1994). The purpose of this study was to compare balance performance and perceived balance self-efficacy in exercising and nonexercising older adults in their 80s and 90s. A secondary purpose was to compare balance variables in persons who used an assistive aid with those who did not use an assistive aid. It was hypothesized that balance performance and balance self-efficacy would be higher in (a) exercising older adults compared to nonexercising older adults and (b) nonaid users compared to aid users.

Postural Balance and Self-Reported Exercise

Method

Participants

A convenience sample of 60 participants, 65 to 95 years, was recruited from a private retirement home that contained 160 beds. A large entrance fee and substan- tial financial resources were required to be admitted to the facility, an indicator of the high socioeconomic status of the sample. The Center was chosen because it contained a supervised fitness center where participants could choose to exercise. Of the 60 participants, all of whom were white, 14 were males (23%) and 46 were females (77%). Means and standard deviations for height, weight, and body mass index W(kg)/H2 (m), are presented in Table 1 to indicate that there was nothing atypical about the sample.

Instruments

The Activities Specific Balance Confidence Scale (ABC) of Powell and Myers (1995) was the first test to be administered. The ABC Scale assesses perceived confidence to perform 16 specific balance-related tasks. Powell and Myers (1995) reported a Cronbach's alpha of 0.96 and a test-retest correlation coefficient of 0.92. Responses to the 16 items comprise the ABC range from 0%, as having no confidence, to loo%, as being completely confident. Responses go in increments of 10 (lo%, 20%, 30% ... 100%). Instructions were read to the participants, or participants received a large print copy that they read in the presence of the test ad- ministrator. Level of balance confidence was indicated by choosing one of the percentage points on the scale for each item.

After completing the ABC scale, the participants performed three balance tests selected in randomized order. Each of the balance measures took approxi- mately 5 min to complete, with a 1 min rest between each test. The participants were allowed to rest for a longer period if necessary.

Table 1 Demographic Data of Participants (n = 60)

Age (years) Height (cm) Weight (kg) Body mass index (kg/m2)

Age (years) Height (cm) Weight (kg) Body mass index (kg/m2)

Exercise (n = 33) Nonexercise (n = 27)

M SD M SD

Aid (n = 18) No aid (n = 42)


The Functional Reach (FR) test was administered according to the procedures of Duncan, Weiner, Chandler, and Studenski (1990). Reported concurrent validity is 0.71 and test-retest reliability is 0.92. A yardstick was secured to the wall at the height of the participant's acromion process on the dominant arm (writing hand). Partici- pants were asked to stand comfortably, make a fist, and raise their arm until it was parallel to the yardstick (position 1). The placement of the end of the third metacarpal along the yardstick was recorded. Participants were then asked to reach as far forward as possible, flexing at their waist, without losing their balance (position 2). The position of the end of the third metacarpal along the yardstick was again recorded to the nearest quarter inch. If a participant touched the wall or took a step during the test, the trial was considered invalid and was repeated. Participants were given three trials. The mean Functional Reach of the trial differences between position 1 and position 2 over three trials was recorded as the score.

The Timed "Up & Go" test has a reported concurrent validity of -31 and test-retest reliability of 0.99 (Podsiadlo & Richardson, 1991). The test began with a demonstration. After one practice trial, participants were given two trials. The best time of the two trials was used as the score. No physical assistance was given during testing. The test began with the participant fully seated in a straight back chair, hands on thighs, and feet flat on the floor. Participants who used an assistive aid were permitted to use it during the test. On the word go, the participant rose from the chair, walked as quickly as possible at a safe and comfortable pace to a line (colored tape) on the floor measured 3 m away, turned, returned to the chair, and sat down. The test ended when the participant was fully seated in the chair.

The One-Legged Stork Stand test has a reported concurrent validity of 0.86 and test-retest reliability of 0.94 (Suni et al., 1998). The test was performed between parallel bars adjusted to hip level for each participant. A demonstration was provided, after which participants performed one practice trial on each leg. Timing began with the participant's feet flat on the floor. The participant was asked to lift one foot off the ground 4 to 6 in. by flexing the knee and holding both hands a few inches above the parallel bars for as long as possible without grasping onto the bars or touching the floor with the nonsupport foot. The test began when the participant's foot was raised off the floor into the lifted position (left foot first, then right). Two trials were performed with each leg. The number of seconds that the leg was held off the floor was recorded, with a maximum time of 60 s for each leg. When the participant's foot touched the floor or one or both hands touched the parallel bars, the test was terminated. The best times of the two trials for each leg were added together and recorded as the participant's score.

Procedure

The research design was ex post facto experimental. Participants were divided into exercise and nonexercise groups and assistive aid and no assistive aid groups for statistical analysis, based on self-reported practices. The exercise group con- sisted of 33 participants (10 males and 23 females) who reported engaging in physical activity a minimum of 30 min per day (e.g., stationary cycling, walking, strength training) 3 days per week (American College of Sports Medicine, 1995). The nonexercise group included 27 participants (4 males and 23 females) who did not meet the activity criterion. Participants were also classified as using an assistive aid (cane or walker) to ambulate (n = 18) and not using an assistive aid (n = 42).

Postural Balance and Self-Reported Exercise 73

The participants signed an informed consent form and completed a personal history form, which were both approved by the Institutional Review Board. Be- cause the tests involved activities that are common to everyday functioning (stretch- ing, walking, stepping), no medical clearance was necessary.

All testing took place in the exercise facility at the local retirement center. The date and time of the testing were determined by the participant's availability. To standardize the test procedures, participants were asked to wear sneakers or flat shoes and loose, nonrestricting clothing so as not to hinder their reach. The floor used to test each balance measure was a flat concrete surface. In order to determine test-retest reliability, subsamples of exercisers (n = 20) and nonexercisers (n = 15) were randomly selected and retested 1 week after their first test date.

Statistical Analysis

Balance performance measures between males and females were not significant (p = .05, df = 58; Functional Reach, t = 0.102; ABC, t = 0.447; Up & Go, t = 0.036; Stork, t = -.250). Therefore, aggregate data were used for all subsequent analyses.

The categorical variables used in the data analysis were exercise status (E, NE) and ambulatory status (Aid, No Aid). The dependent variables were the scores on the Activities-Specific Balance Confidence Scale recorded in percentages, the Timed "Up & Go" test score recorded in seconds, the Functional Reach test recorded in inches, and the One-Legged Stork Stand test recorded in seconds.

In order to establish test-retest reliability for each of the four dependent variables, an intraclass correlation coefficient was calculated. Test-retest reliability (n = 35,7 males and 28 females) was conducted on 2 separate days with a 7 - y interval between tests. The intraclass coefficients for the four dependent measures were 0.86 on the Functional Reach, 0.87 on the Stork Stand, 0.90 on the ABC Scale, and 0.96 on the Timed "Up & Go" test.

Nonparametric statistics were used because there were outliers in the data set that skewed the distributions of the variables. Since there was no legitimate reason to omit these outliers from the data set, the assumption of a normal distribu- tion was violated, and a nonparametric test was used. The median (Mdn) and interquartile range (IQR) were computed for each variable (Vogt, 1993), using the SPSS (version 6.1) software package. Effect sizes (ES) were calculated for the exercise (E) and nonexercise (NE) and assistive aid (A) and no assistive aid (NA) groups using the following formula (Wolf, 1986):

ES = Mean - Mean ,,. Results

The Mann-Whitney U Test was used to determine whether the scores on the four tests were significantly different between participants who exercised and those who did not exercise. The results are presented in Table 2. The data revealed that the exercise group had significantly higher scores on all four measures (p < .01). Effect sizes (ES) for all measures denoted large differences between groups (Cohen, 1977).


The Mann-Whitney U Test was also used to determine whether the four dependent measures were significantly different between participants who used an assistive aid and those who did not use an assistive aid. The results are presented in Table 3. Participants who did not use an assistive aid had significantly higher scores on the Activities-Specific Balance Confidence Scale, the Timed "Up & Go" test, and the One-Legged Stork Stand (p 5.01). There was no differ- ence between groups on the Functional Reach test (p 2 .01). Effect sizes for all measures were large.

Discussion

The main finding of this study was that older adults who regularly exercised, most of whom were in their 80s and 90s, had higher balance self-efficacy and balance performance scores than nonexercising older adults. Although a cause and effect relationship cannot be established from this study, the results suggest that regular exercise is a variable that discriminates between levels of postural balance. This has important implications for reducing the incidence of falls and maintaining a higher level of mobility in older populations.

Table 2 Results of the Mann-Whitney U Between Exercisers and Nonexercisers on Self-Efficacy and Balance Measures

Exercisers (n = 33) Nonexercisers (n = 27)

Mdn IQR Mdn IQR U ES

ABC (%) 85 23 60 30 159.5" 1.1 UP & go 6) 6.6 1.8 10.0 3.7 90.5* -1.4 FR (in.) 11.4 3.0 8.4 2.7 184.5" 1.2 Stork stand (s) 21.0 24.1 7.0 4.5 166.5* 3.1

*Significant at 0.01 level.

Table 3 Results of the Mann-Whitney U Between Assistive Aid Users and Nonusers on Self-Efficacy and Balance Measures

Aid (n = 18) No aid (n = 42)

Mdn IQR Mdn IQR U ES

ABC (%) 54 23 84 27 88.0* 1.7 UP & go 6) 10.2 3.5 6.9 1.7 146.0" -1.1 FR (in.) 8.8 2.8 10.7 2.9 248.0 0.8 Stork stand (s) 7.3 6.2 16.0 3.5 190.5* 2.3

"Significant at 0.01 level.


Another finding of our study was that older adults who did not use an assistive aid had significantly higher balance self-efficacy scores compared to participants who did use an assistive aid. This is in agreement with Powell and Myers (1995), who found that a group of 30 high mobility older adults, who did not use an assistive aid, expressed greater balance confidence than a group of 30 low mobility older adults who did use an assistive aid. Since most persons who use an assistive aid have difficulty with balance (Powell & Myers, 1995), this is not an unusual finding but does shed light on the importance of developing intervention strategies that target individuals with the greatest need (e.g., those who use assistive aids).

Research on the relationship between exercise and postural balance in older adults has been inconclusive (Alexander, 1994). Era and colleagues (1997) found that physical activity was consistently and significantly associated with performance on several different balance tests. They reported that physically active older adults (M age = 75 yr) had better control of their posture and, therefore, better balance than sedentary adults. Several other studies have also demonstrated an improvement in postural balance in older adults after an exercise intervention (Lord, Ward, & Williams, 1996; Pyka, Lindenberger, Charette, & Marcus, 1994).

Other studies, however, have not supported an association between exercise and improvements in postural balance (Lichenstein, Shields, Shiavi, & Burger, 1989; Lord, Caplan, &Ward, 1993). In a retrospective study by Lord et al. (1993), 21 women ages 57 to 75 years (only 4 participants were over 70 years of age), who had been taking part in a 12-month exercise program, were measured on balance (body sway performance), reaction time, and strength. The women were compared to 21 women of the same age who were not exercising more than 30 min a day. Lord et al. (1993) reported that the women in the exercise group showed significant improvements on only one of four balance measures (body sway with eyes closed on a foam surface). The other three measures (body sway with eyes open on floor surface, body sway with eyes closed on a floor surface, and body sway with eyes open on a foam surface) showed no improvements.

Lichenstein et al. (1989), in a 16-week program to determine if exercise could improve balance in women over 65 years, found no significant differences between exercisers (n = 24) and controls (n = 26). In an extensive review of the literature on the relationship between postural balance and exercise, Alexander (1994) noted that training programs in older adults have not achieved consistently striking gains in the ability to maintain postural balance.

Our findings suggest that regular exercise is a variable that discriminates between balance performance and balance self-efficacy in older adults. These results may be attributable to the reciprocal effects of two factors: exercise helps to maintain balance, and good balance makes it possible to maintain an active lifestyle. Given the fact that the "over 85" age group is the fastest growing segment of the older population (Campion, 1994), it is important for researchers to continue to study the relationship between habitual exercise and postural balance in this group. Future research in balance and balance self-efficacy in older adults should use true experimental designs (as opposed to quasi-experimental) and include a wider variety of dynamic and static balance measures, varied ethnic groups, and different disease states (i.e., Parkinson's Disease, Alzheimer's Disease). Researchers should also study the effects of a variety of exercise training programs on balance self- efficacy and balance performance in older adults in order to determine what types of exercise have the most benefit for improving balance. The effects of medication on balance test performance and exercise involvement should also be studied.


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Author's Note

This work was supported, in part, by grants from the Centers for Disease Control and Prevention, Secondary Conditions Prevention Branch, Announce- ment 731, #CCR514155-02, and the National Institute on Aging Midwest Roybal Center for Health Maintenance, PSO AG15890.

A special thanks to Dr. Marilyn Looney, Professor, Northern Illinois University, for her statistical consultation.

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