Biomedical subjects

Lori Ploutz-Snyder

Publications and source records attributed to Lori Ploutz-Snyder.

4 recordsLinked to original sources

PubMed2006

Evaluating task modification as an objective measure of functional limitation: repeatability and comparability.

BACKGROUND: Modification of everyday tasks in older adults is associated with risk of deleterious health outcomes. The purpose of this study was to develop a task modification scale to examine its reliability and comparability to timed performance and common measures of physical function and impairment. METHODS: Eighty-two (21 men, 61 women) older adults (74.4 +/- 8.2 years) were observed performing a chair rise (sitting heights: 43 cm, 38 cm, and 30 cm), stair ascent/descent, and kneel and supine rise tasks. Six hierarchically ranked categories (0-5) of modification were created for each task and then summed across tasks (summary modification [MOD] score: range 0-35). Comparisons were made with timed performance, knee extension strength, single-leg balance, self-reported function, five chair stands, and gait speed. RESULTS: Inter-rater reliability (intra-class correlation = 0.98) and participant repeatability (intra-class correlation = 0.92) of the MOD score were excellent. Ninety-six percent of participants modified at least one task (MOD score: 10.5 +/- 7.51, range 0-27). After adjusting for task modification, timed performance showed a lower association with gait speed (time vs MOD score, semipartial r2 = 0.31 vs 0.68), strength (semipartial r2 = 0.14 vs 0.65), and single-leg balance (semipartial r2 = 0.10 vs 0.40) than did the MOD score. The MOD score showed higher correlations with muscle strength and balance impairment than did other measures of functional limitation such as gait speed, time to complete five chair stands, and self-reported physical function. CONCLUSION: Documentation of task modification is reliable across raters and repeatable within participants; in addition, it compares well with other measures of physical function and impairment. Task modification reveals important and intuitive information regarding physical limitation, and deserves greater attention.

Activities of Daily Living↗

PubMed2005

Resistance and functional training reduces knee extensor position fluctuations in functionally limited older adults.

The purpose of this study was to determine the effect of task-specificity on knee extensor steadiness adaptations in functionally limited older adults. Twenty-four functionally limited older adults (74.6+/-7.6 years: 22 women, 2 men) completed a 10-week control period followed by 10 weeks (2 days/week) of resistance (RT), functional (FT) (practicing everyday tasks, i.e., chair rises) or functional + resistance (FRT) training, which featured both shortening and lengthening movements. During testing, subjects performed a steady isometric [10, 25, 50% of maximal voluntary contraction (MVC)] and shortening/lengthening (5, 30, 65% of MVC) knee extensor contractions. There were no steadiness (isometric, shortening or lengthening contractions) changes in the control period and no adaptations in isometric steadiness due to training. RT induced a 37% reduction in shortening fluctuations at 5% of MVC and 35% reduction in lengthening fluctuations at both 30% and 65% of MVC. FRT induced a 60% reduction in shortening fluctuations at 30% of MVC. No adaptations in dynamic steadiness were observed in the FT group. Further analysis indicated that those who were the least steady at baseline showed the greatest training effects during isometric (RT: R (2)=0.25, FRT: R (2)=0.49, FT: R (2)=0.38), shortening (RT: R (2)=0.36, FRT: R (2)=0.36, FT: R (2)=0.35) and lengthening (RT: r (2)=0.29, FRT: r (2)=0.44) contractions. In conclusion, steadiness improvements in groups performing resistance exercise, without a concomitant improvement in the FT group, supports a role for task-specificity in explaining steadiness adaptations, particularly for unsteady older adults.

Activities of Daily Living↗

PubMed2005

Misconceptions about strength exercise among older adults.

The purposes of this study were to determine current opinions of strength exercise among older adults and whether knowledge of recommended protocols differs between strength-exercise participants and nonparticipants. One hundred twenty-nine older adults (77.5 +/- 8.6 years) responded to questions about their opinions, experiences, and knowledge of strength-exercise recommendations. Some misconceptions were identified in the sample, with 48.4% of participants responding "no" to "strength training increases muscle mass," 45% responding "no" to "increasing weight is more important than number of repetitions for building strength," and 37% responding that walking is more effective than lifting weights at building muscle strength. The number of correct responses was related to the number of years in school (semipartial r(2)= .046). More education is needed about the benefits and recommendations to ensure proper use of current strength-exercise protocols among older adults.

Age Factors↗

PubMed2003

Age, body mass, and gender as predictors of masters olympic weightlifting performance.

PURPOSE: The purpose of this study was to examine previously collected performance scores from the 2000 World Masters Weightlifting Championships to 1). determine the extent to which age and body mass are related to and predictive of indirect estimates of absolute and relative muscular power, and 2). assess possible gender differences in these associations. METHODS: Dependent variables were absolute load (ABS = heaviest snatch [kg] + heaviest clean and jerk [kg]) and relative load (REL = ABS [kg]/body mass [kg]), representing indirect estimates of absolute and relative muscular power, respectively. Predictor variables were age (yr) and body mass (kg). Linear regression and various diagnostic procedures were used to analyze the data. RESULTS: The linear model provided an adequate fit for the data because no departures from the usual assumptions of normally distributed variables and homoscedastic error variance were observed. All predictor variables were significantly (P < 0.05) predictive of the dependent variables, but the magnitude of associations (e.g., R(ABS|BM) = 0.18 among females vs R(ABS|BM) = 0.57 among males) and extent of predictive ability (e.g., R(adj)2 for regression of ABS on age and body mass was 0.18-0.58 among females vs 0.74-0.83 among males) were significantly (P < 0.05) higher among males versus females. CONCLUSION: The extent to which age and body mass explain differences in muscular power differs between female and male masters weightlifters, but the rate of decline (%.yr-1) in power with advancing age is similar and is in agreement with previous reports for world record holders, other masters athletes, and healthy, untrained individuals, suggesting the importance of the aging process itself over physical activity history.

Adult↗