Effects of cognitive task demands on subsequent symptoms and activity in adults with symptomatic osteoarthritis.

OBJECTIVE: Adults with osteoarthritis (OA) experience fatigue in daily life that is negatively related to physical activity; however, it is unclear how task demands affect fatigue and occupational performance. We examined effects of a cognitive task on subsequent symptoms and activity. METHOD: Adults with knee or hip OA completed a standardized cognitive task during a lab visit. Objective physical activity and symptoms were tracked during two home-monitoring periods (i.e., 4-day period before and 5-day period after the lab visit). Multilevel modeling was used to compare pretask with posttask fatigue, pain, and activity levels. RESULTS: Fatigue increased and pain decreased for 2 days after performing the lab task. The authors found no pretask to posttask changes in activity levels. At posttask, daily fatigue and activity patterns changed relative to baseline. CONCLUSION: For adults with symptomatic OA, cognitive task demands may be an important contributor to fatigue and pain.

Effect of tailored activity pacing on self-perceived joint stiffness in adults with knee or hip osteoarthritis.

OBJECTIVE: We examined the effects of a tailored activity-pacing intervention on self-perceived joint stiffness in adults with osteoarthritis (OA). METHOD: Thirty-two adults with hip or knee OA were randomized to a tailored or general activity-pacing intervention. Participants' symptoms and physical activity over 5 days were used to tailor activity pacing. The outcome was self-perceived joint stiffness measured at baseline, 4 wk, and 10 wk. A linear mixed regression model was used. RESULTS: The tailored group significantly improved in stiffness compared with the general group over time. We found a significantly different linear trend between groups (Time × Group, p = .046) in which the tailored group had decreasing stiffness over the three time points, denoting continued improvement. The general group's stiffness improved from baseline to 4 wk but returned to baseline levels at 10 wk. CONCLUSION: Tailoring activity pacing may be effective in sustaining improvements in self-perceived joint stiffness in adults with OA.

Relationship between fall-related efficacy and activity engagement in community-dwelling older adults: a meta-analytic review.

OBJECTIVE: Fear of falling can lead to restricted activity, but little is known about how this fear affects different aspects of people's lives. This study examined the relationship between fall-related efficacy (i.e., confidence or belief in one's ability to perform activities without losing balance or falling) and activity and participation. METHOD: We conducted a meta-analysis of studies comparing community-dwelling older adults' fall-related efficacy to measures of activity or participation. RESULTS: An examination of 20 cross-sectional and prospective studies found a strong positive relationship between fall-related efficacy and activity (r = .53; 95% CI [.47, .58]). An insufficient number of studies examining fall-related efficacy and participation were available for analysis. CONCLUSION: Low fall-related efficacy may be an important barrier to occupational engagement for many older adults and warrants careful consideration by occupational therapists. Future research should explore interventions that target fall-related efficacy and examine their effects on activity performance and engagement.

Fatigability in osteoarthritis: effects of an activity bout on subsequent symptoms and activity.

BACKGROUND: Older adults with osteoarthritis (OA) are more likely to experience increased fatigue following bouts of physical activity than those without OA. The highly "fatigable" nature of this population is problematic as it has been linked to OA severity and decreased function. This study examined the effects of engaging in standardized lab-based physical tasks on subsequent fatigue, pain, and activity in older adults with OA. METHODS: Thirty-five older adults with OA performed lab-based tasks (sweeping, grocery shopping, and walking) in 15-minute circuits until they felt too fatigued to continue. Fatigue and pain were self-reported (0-10 scale) following each circuit and at set intervals during a 4-day baseline (pretask) and a 5-day posttask home period. Activity was tracked via wrist-worn accelerometer. Multilevel modeling was used to examine levels and patterns of fatigue, pain, and activity across the study period. RESULTS: The lab-based tasks altered subsequent levels and patterns of fatigue and activity but had no effects on pain. Compared with baseline, on the day of the lab-based tasks, fatigue was higher and more stable, and activity was significantly lower and dropped steadily toward evening. Activity returned to baseline levels and patterns by the day following the lab-based tasks while fatigue was lower for 3 days following task performance. CONCLUSIONS: Among older adults with OA, a bout of standardized physical activity resulted in increased fatigue and reduced activity, but effects were short-lived. Future studies will need to identify factors that differentiate people who are particularly fatigable in order to target interventions.

Measurement error and minimum detectable change in 4-meter gait speed in older adults.

BACKGROUND AND AIMS: Gait speed is a commonly-used assessment and outcomes measure in geriatric clinical and research settings. Although relative reliability of usual gait speed has been well studied in community- dwelling older adults, less emphasis has been placed on a measure of absolute reliability (the standard error of measurement [SEM]), and on an associated clinically relevant index of real change in gait speed, minimum detectable change (MDC). The purpose of this study was to quantify measurement error and MDC for usual gait speed over 4 meters in community-dwelling older adults ambulating at intermediate and fast speeds. METHODS: Community-dwelling older adults ambulating at intermediate gait speed (IGS), (n=15, mean age 74.2 yrs) and fast gait speed (FGS), (n=15, mean age 72.1) were included in this study. Participants performed two trials of gait speed over a distance of 4 meters. SEM and MDC at the 95% confidence level (MDC95) were computed for the IGS and FGS groups. RESULTS: Mean gait speed was 85.4 cm/s (IGS) and 129.9 cm/s (FGS). Measurement error (<5% of mean gait speed) and minimum detectable change (<13% of mean gait speed) were low in both groups. MDC95 was computed as 10.8 cm/s and 14.4 cm/s for the IGS and FGS groups, respectively. CONCLUSIONS: To be considered real change beyond the bounds of measurement error, change in 4-meter gait speed should exceed 10.8 cm/s (for intermediate speed ambulators) or 14.4 cm/s (for fast speed ambulators). Low measurement error in assessing 4-meter gait speed in community-dwelling older adults suggests that gait speed assessed over short distances has excellent reproducibility across trials. Low minimum change values suggest that 4-meter gait speed may be responsive and sensitive to change.

Randomized controlled trial comparing tailoring methods of multimedia-based fall prevention education for community-dwelling older adults.

OBJECTIVE: We attempted to determine whether multimedia fall prevention education using different instructional strategies increases older adults' knowledge of fall threats and their fall prevention behaviors. METHOD: Fifty-three community-dwelling older adults were randomized to iwo educational groups or a control group. Multimedia-based educational interventions to increase fall threats knowledge and encourage fall prevention behaviors had two tailoring strategies: (1) improve content realism for individual learners (authenticity group) and (2) highlight program goals and benefits while using participants' content selections (motivation group). Knowledge was measured at baseline and 1-mo follow-up. Participants recorded prevention behaviors for 1 mo. RESULTS: Intervention group participants showed greater knowledge gains and posttest knowledge than did control group participants. The motivation group engaged in more prevention behaviors over 1 mo than did the other groups. CONCLUSION: Tailoring fall prevention education by addressing authenticity and motivation successfully improved fall threats knowledge. Combining motivational strategies with multimedia education increased the effectiveness of the intervention in encouraging fall prevention behaviors.

Concurrent validity and reliability of the maximum step length test in older adults.

PURPOSE: This study assessed concurrent validity of the Maximum Step Length (MSL) test as a measure of falls risk and balance-impairment for community-dwelling older adults. A secondary purpose was to determine intra- and interrater reliability and standard error of measurement of the MSL test. METHODS: Thirty-five community-dwelling adults aged 60 or older provided a 12-month falls history. Functional measures included the MSL test, Single Limb Stance Time, Functional Reach test, Timed Up and Go test, and a test of trunk position sense. Pearson correlation coefficient, intraclass correlation coefficient (a coefficient of relative reliability), and standard error of measurement (a measure of absolute reliability) were calculated as indices of concurrent validity and reliability of the MSL test. Minimal detectable change was also calculated; this represents actual change beyond that of measurement error or random variation in stepping performance. RESULTS: Correlations between MSL score and clinical balance measures and self-reported number of falls in the past 12 months ranged from fair to good. Same-day and 1-month intrarater test-retest reliability of the MSL test was excellent. Same-day interrater reliability between 2 raters was also excellent. Measurement error of the MSL test was low. Minimal detectable change for the MSL test at the 95% confidence level was 7.32 inches. CONCLUSION: The MSL test appears to be a valid and reliable measure of balance-impairment and falls risk in older adults. Clinicians should consider incorporating the MSL test into their battery of falls risk assessment tools. Use of this test as a screening measure may reduce the incidence of falls in community-dwelling older adults. Real change in performance requires a difference of more than 7.32 inches between trials; differences less than this should be interpreted as being due to measurement error or random variation in stepping performance.

Deficits in stepping response time are associated with impairments in balance and mobility in people with Huntington disease.

Huntington disease (HD) is a disorder characterized by chorea, dystonia, bradykinesia, cognitive decline and psychiatric comorbidities. Balance and gait impairments, as well as falls, are common manifestations of the disease. The importance of compensatory rapid stepping to maintain equilibrium in older adults is established, yet little is known of the role of stepping response times (SRTs) in balance control in people with HD. SRTs and commonly-used clinical measures of balance and mobility were evaluated in fourteen symptomatic participants with HD, and nine controls at a university mobility research laboratory. Relative and absolute reliability, as well as minimal detectable change in SRT were quantified in the HD participants. HD participants exhibited slower SRTs and poorer dynamic balance, mobility and motor performance than controls. HD participants also reported lower balance confidence than controls. Deficits in SRT were associated with low balance confidence and impairments on clinical measures of balance, mobility, and motor performance in HD participants. Measures of relative and absolute reliability indicate that SRT is reliable and reproducible across trials in people with HD. A moderately low percent minimal detectable change suggests that SRT appears sensitive to detecting real change in people with HD. SRT is impaired in people with HD and may be a valid and objective marker of disease progression.

The short version of the Activities-specific Balance Confidence (ABC) scale: its validity, reliability, and relationship to balance impairment and falls in older adults.

A shortened version of the ABC 16-item scale (ABC-16), the ABC-6, has been proposed as an alternative balance confidence measure. We investigated whether the ABC-6 is a valid and reliable measure of balance confidence and examined its relationship to balance impairment and falls in older adults. Thirty-five community-dwelling older adults completed the ABC-16, including the 6 questions of the ABC-6. They also completed the following clinical balance tests: unipedal stance time (UST), functional reach (FR), Timed Up and Go (TUG), and maximum step length (MSL). Participants reported 12-month falls history. Balance confidence on the ABC-6 was significantly lower than on the ABC-16, however scores were highly correlated. Fallers reported lower balance confidence than non-fallers as measured by the ABC-6 scale, but confidence did not differ between the groups with the ABC-16. The ABC-6 significantly correlated with all balance tests assessed and number of falls. The ABC-16 significantly correlated with all balance tests assessed, but not with number of falls. Test-retest reliability for the ABC-16 and ABC-6 was good to excellent. The ABC-6 is a valid and reliable measure of balance confidence in community-dwelling older adults, and shows stronger relationships to falls than does the ABC-16. The ABC-6 may be a more useful balance confidence assessment tool than the ABC-16.

Changes in hemiplegic grasp following distributed repetitive intervention: a case series.

The purpose of this pilot study was to investigate the efficacy of a distributed model of repetitive and focused intervention on grasp force, and clinical and functional hand measures in persons with chronic hemiplegia and limited hand recovery from self-reported stroke. A case series design was used. Focused repetitive unilateral and bilateral interventions were provided in a distributed manner (three times a week for 6 weeks) to three persons with upper limb hemiplegia of more than 1 year. Data from instrumented grasp force, and clinical and functional measures were obtained at weeks 0, 3, 6 and 9. Each participant improved in at least one measure of grasp force, as well as in clinical skill and function. All participants improved in the quality of handwriting. Improved outcomes remained above baseline levels following 3 weeks of non-intervention. The findings are compatible with current evidence of adaptive cortical plasticity following increased repetition. The findings show that, for these three persons, distributed repetitive practice was sufficient to effect change. Localization by cerebral area affected is not possible, nor is it possible to parse the effectiveness of any component of the intervention. A larger group study is warranted to determine whether similar results may be found for other persons with chronic hemiplegia. Future studies should incorporate kinematic handwriting analysis and a greater range of functional tasks.