Age- and activity-related differences in the mechanisms underlying maximal power production in young and older adults.

The purpose of this study was to examine the interactions between aging, activity levels and maximal power production during cycling. Participants were divided into younger adults (YA), older active adults (OA,) and older sedentary adults (OS). Absolute maximum power was significantly greater in YA compared with OS and OA; no differences were found between OA and OS. The age-related difference in maximum power was accompanied by greater absolute peak knee extension and knee flexion powers. Relative joint power contributions revealed both age- and activity-related differences. YA produced less relative hip extension power than older adults, regardless of activity level. The OS participants produced less relative knee flexion power than active adults, regardless of age. The results show the age-related decline in muscular power production is joint specific and that activity level can be a modifier of intersegmental coordination, which has implications for designing interventions for the aging population.

Gait variables differentiating fallers from nonfallers.

PURPOSE: This study examined the qualitative and quantitative differences between 2 groups of older adults, fallers and nonfallers. We compared walking differences during overground walking to a task of obstacle clearance. METHODS: Forty-eight community dwelling older adults (18 fallers and 30 nonfallers) participated. The mean age of the participants was 78.1 +/- 7.2 years (fallers) and 75.8 +/- 5.1 years (nonfallers). Walking differences within and between fallers and nonfallers during a single visit for 6 conditions were examined: (1) baseline walking, (2) slow walking, (3) fast walking, and (4) 5 cm obstacle clearance - approach, during, and exit. Quantitative differences of temporal-spatial walking measures were analyzed using a multifactorial ANOVA adjusted for age, gender, height, and BMI with a Scheffe correction (p < 0.05) applied for multiple testing. Qualitative data were analyzed using Chi-square fisher's exact test. RESULTS: There were interaction effects for group by walking condition for single support (p = 0.002) and step length (p = 0.05), while 1st double support approached significance (p = 0.06). Main Group effects were found during the comfortable walk (p < 0.001-0.05) for all 7 gait variables. Qualitatively, the fallers demonstrated increased knee flexion during both over ground walking (c2 = 9.01 ; p < 0.006), and the fallers consistently took several small steps immediately prior to the obstacle clearance (c2 = 8.42 ; p = 0.007). CONCLUSION: There were significant differences in quantitative and qualitative walking characteristics differentiating fallers from nonfallers during over-ground walking at different velocities and during obstacle clearance.

The effects of yoga on physical functioning and health related quality of life in older adults: a systematic review and meta-analysis.

OBJECTIVE: The goal was to review systematically the comparative effectiveness of yoga, compared with other exercise interventions, for older adults as shown on measures of health and physical functioning. DESIGN: This was a systematic review with both narrative synthesis and meta-analysis. DATA SOURCES: Searches were conducted in MEDLINE®/PUBMED, PSYCINFO, CINAHL, Web of Science, and SCOPUS; bibliographies of selected articles; and one systematic review on the effects of yoga on cardiovascular disease. METHODS: Original studies from 1950 to November 2010 were sought, evaluating the effects of yoga on older adults. The search was restricted to randomized controlled trials of yoga in subjects ≥age 60, and published in English. Data were extracted and evaluated regarding setting, population size and characteristics, intervention type and duration, comparison group, outcome assessment, data analysis, follow-up, key results, and the quality of each study according to specific predetermined criteria. RESULTS: The search yielded 18 eligible studies (N=649). The studies reported on older adults across a range of settings, intervention intensity, and outcome measures. The majority of the studies had<35 participants (range 9-77). Quantitative and qualitative synthesis of the studies suggested that the benefits of yoga may exceed those of conventional exercise interventions for self-rated health status, aerobic fitness, and strength. However, the effect sizes were modest, and the evidence was mixed for yoga's effect on depression, sleep, and bone-mineral density. Studies did not find an effect on cognition. CONCLUSIONS: Small studies with mixed methodological quality suggested that yoga may be superior to conventional physical-activity interventions in elderly people. The precision of the estimates remains low. Larger studies are necessary to define better the intersection of populations, settings, and interventions in which yoga is most beneficial.

Reliability of the Berg Balance Scale and balance master limits of stability tests for individuals with brain injury.

PURPOSE: The purpose of this study was to determine the test-retest reliability of 2 measurement tools used to examine balance in persons with brain injury. METHODS: Five participants (ages 20-32) were recruited from a transitional living facility in Galveston, Texas. Each participant performed the Berg Balance Scale (BBS) and Balance Master Limits of Stability Test (BMLOST) sequence in random order on the same day and 1 week later. RESULTS: The test-retest reliability for the BBS was excellent (ICC2,1 = 0.986). Reliability of the BMLOST ranged from poor for weight shifts (ICC2,1 = 0.228) to good, for movement time (ICC2,1 = 0.825) and path sway (ICC2,1 = 0.846). DISCUSSION: The BBS, a function based test, was found to have greater test-retest reliability than the BMLOST, a strategy level test. The scores of the BBS were high and may suggest the potential of ceiling effects. CONCLUSION: Preliminary test-retest reliability for both the BBS and aspects of the BMLOST for persons with brain injury was demonstrated. The value of administering the tests in isolation or combination for patients with brain injury is yet to be determined.