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Walking Speed (walking + speed)
Kinds of Walking Speed Selected AbstractsTemperature influences walking speed and walking activity of Trichogramma brassicae (Hym., Trichogrammatidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 6 2001B. P. Suverkropp Walking speeds and walking activities (walking time divided by total time) of Trichogramma brassicae were determined at 12, 16, 20 and 25°C. Walking speed was measured during a 5-min period, and walking activity over a 4-day period. Both walking speed and walking activity were strongly influenced by temperature. Walking speed increased linearly with the temperature and was twice as high at 20 as at 12°C. At 25°C, walking activity was high during the whole day, at 20 and 16°C it decreased during the afternoon, whereas at 12°C the wasps became most active only at noon or later. At low temperatures, there was a strong individual variation in walking activity. At 25°C, T. brassicae was active most of the time, so the area searched per time unit can only increase at temperatures above 25°C if walking speed increases. At temperatures below 20°C, searching was more restricted by low walking activity than by low walking speed. Even disregarding other effects of temperature, the reduction in walking speed and walking activity at suboptimal temperatures means that T. brassicae can only search half of the area at 20°C, and only one-seventh at 15°C that it can search at 25°C. [source] Walking on an Uneven Surface: The Effect of Common Peroneal Stimulation on Gait Parameters and Relationship Between Perceived and Measured Benefits in a Sample of Participants With a Drop-FootNEUROMODULATION, Issue 1 2007Jane H. Burridge PhD ABSTRACT Objectives., To examine the effect of using a common peroneal stimulator on an even and an uneven surface, and to compare measures with perceived response to stimulation. Method., Participants had a drop-foot caused by a stroke (N = 13) or multiple sclerosis (N = 7) and had used a common peroneal stimulator for > 3 months prior to the study. Walking speed and physiological cost index (PCI) were recorded under four conditions: with and without stimulation over an even and an uneven surface. Participants also completed a questionnaire. Results., A statistically significant increase in walking speed and decrease in PCI was identified when the stimulator was used. There was a trend to greater improvement on the uneven compared to the even surface. A correlation between perceived benefit of stimulation and a measured decrease in PCI was detected. Conclusion., Stimulation may be particularly beneficial for the more difficult task of walking on an uneven surface. Perceived benefit was related to a reduction in effort of walking, not in increased speed. [source] Temperature influences walking speed and walking activity of Trichogramma brassicae (Hym., Trichogrammatidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 6 2001B. P. Suverkropp Walking speeds and walking activities (walking time divided by total time) of Trichogramma brassicae were determined at 12, 16, 20 and 25°C. Walking speed was measured during a 5-min period, and walking activity over a 4-day period. Both walking speed and walking activity were strongly influenced by temperature. Walking speed increased linearly with the temperature and was twice as high at 20 as at 12°C. At 25°C, walking activity was high during the whole day, at 20 and 16°C it decreased during the afternoon, whereas at 12°C the wasps became most active only at noon or later. At low temperatures, there was a strong individual variation in walking activity. At 25°C, T. brassicae was active most of the time, so the area searched per time unit can only increase at temperatures above 25°C if walking speed increases. At temperatures below 20°C, searching was more restricted by low walking activity than by low walking speed. Even disregarding other effects of temperature, the reduction in walking speed and walking activity at suboptimal temperatures means that T. brassicae can only search half of the area at 20°C, and only one-seventh at 15°C that it can search at 25°C. [source] Clinical Application of Peroneal Nerve Stimulator System Using Percutaneous Intramuscular Electrodes for Correction of Foot Drop in Hemiplegic PatientsNEUROMODULATION, Issue 4 2006Yoichi Shimada MD Abstract Objective., To assess the orthotic effect of a functional electrical stimulation device (Akita Heel Sensor System; AHSS) in the treatment of hemiplegic gait with foot drop. Materials and Methods., In the AHSS, a heel sensor is attached to a small plastic heel brace, and the peroneal nerve is stimulated via percutaneous intramuscular electrodes. During the swing phase of the hemiplegic gait, the common peroneal nerve is stimulated by the AHSS. Eight patients in chronic stages of hemiplegia participated in this study. Walking speeds and step cadences on a 10-m course were compared between walking with stimulation and walking without stimulation. Results., Mean walking speed (± SD) was 0.50 ± 0.26 m/sec without stimulation and 0.64 ± 0.31 m/sec with stimulation. The mean percentage increase in walking speed with stimulation was 30.1%. Mean step cadence was 31 ± 7 steps/10 m without stimulation and 27 ± 7 steps/10 m with stimulation. By correcting foot drop, the AHSS significantly increased walking speed and decreased cadence (p < 0.05). Conclusion., The AHSS can significantly improve walking in hemiplegic patients with foot drop. [source] Impact of nC24 agricultural mineral oil deposits on the searching efficiency and predation rate of the predatory mite Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae)AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 3 2009Yingen Xue Abstract Walking activity, walking straightness, walking speed and searching efficiency of the predatory mite Phytoseiulus persimilis Athias-Henriot were measured on French bean leaf discs that were sprayed with either distilled water, or one of 0.25%, 0.50% and 1.00% w/w aqueous emulsions of an nC24 agricultural mineral oil (AMO). There was no significant difference in percentage of time that mites spent walking in the control (water-sprayed) conditions and in any of the oil treatments. Walking paths were significantly straighter in the oil treatments than in the control, but differences among the oil treatments did not differ significantly. Walking speeds in the oil treatments were significantly slower than in the control and decreased with increasing oil concentration. Deposits of oil at all concentrations significantly suppressed searching efficiency in comparison with control, and searching efficiency in the 1.00% oil treatment was significantly lower than in the 0.25% oil treatment. First predation of P. persimilis on AMO-contaminated eggs of two-spotted mite (Tetranychus urticae Koch) on unsprayed leaf discs was significantly delayed in all oil treatments in comparison with the control. However there was no significant effect on the overall predation rate. In the tests of P. persimilis predation on AMO-contaminated T. urticae eggs on sprayed leaf discs, the number of first predation occurrences in the first hour was significantly lower in 0.50% and 1.00% oil treatments than in the control. Overall predation rates were significantly reduced by oil but they did not differ significantly among the oil treatments. [source] Ankle dorsiflexion fMRI in children with cerebral palsy undergoing intensive body-weight-supported treadmill training: a pilot studyDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 1 2007John P Phillips MD This pilot study investigated the feasibility of using functional magnetic resonance imaging (fMRI) as a physiological marker of brain plasticity before and after an intensive body-weight-supported treadmill training (BWSTT) program in children with cerebral palsy (CP). Six ambulatory children (four males, two females; mean age 10y 6mo, age range 6,14y) with spastic CP (four hemiplegia, two asymmetric diplegia, all Gross Motor Function Classification System Level I) received BWSTT twice daily for 2 weeks. All children tolerated therapy; only one therapy session was aborted due to fatigue. With training, over ground mean walking speed increased from 1.47 to 1.66m/s (p=0.035). There was no change in distance walked for 6 minutes (pre-: 451m; post-: 458m;p 0.851). In three children, reliable fMRIs were taken of cortical activation pre- and post-intervention. Post-intervention increases in cortical activation during ankle dorsiflexion were observed in all three children. This study demonstrates that children with CP between 6 and 14 years of age can tolerate intensive locomotor training and, with appropriate modifications, can complete an fMRI series. This study supports further studies designed to investigate training-dependent plasticity in children with CP. [source] Improved cardiovascular health following a progressive walking and dietary intervention for type 2 diabetesDIABETES OBESITY & METABOLISM, Issue 9 2009S. T. Johnson Aim: To examine the impact of two different lifestyle programmes on cardiovascular health and glycaemic control among people with type 2 diabetes. Methods: A two-phase 24-week randomized trial. During the first phase, participants were to increase daily steps using a pedometer. At week 12, participants were randomly allocated to either an enhanced lifestyle programme (ELP) targeting walking speed or a basic lifestyle programme (BLP) targeting total daily steps. Both programmes focused on increasing the intake of low glycaemic index foods but utilized different goal setting strategies. Clinical measurements were completed at baseline, week 12 and week 24. Principal outcomes were change in resting pulse rate (PR) and glycated haemoglobin A1c (A1c) between week 12 and week 24 compared between groups using analysis of covariance. Results: Forty-one participants [mean ± s.d. : age = 56.5 ± 7.2 years, body mass index (BMI) = 32.7 ± 6.1 kg/m2] were randomized. After 12 weeks, we observed an increase in average total daily steps of 1562 (95% confidence interval: 303,2821, p = 0.02). Weight, BMI and systolic and diastolic blood pressure improved (p < 0.01 for all). No changes were observed for energy intake. At week 24, those in the ELP had a lower resting PR (71 ± 12 b.p.m.) compared with those in the BLP (78 ± 12 b.p.m.) (adjusted p = 0.03), while no group differences for total daily steps or glycaemic control were observed. Conclusions: Improvements in cardiovascular health can be expected following a pedometer-based lifestyle modification programme that progresses from walking more to walking faster. [source] Ancestral feeding and survival of offspring in European corn borerENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2002D.A. Andow Abstract Experiments were conducted to evaluate the influence of ancestral adult feeding by European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), on larval survival in the field and neonate movement behavior in laboratory. Larval survival was higher when either the grandparental or parental generation had fed, but the feeding sites of the surviving larvae were not affected by ancestral feeding condition. This is the first evidence that grandparental feeding could influence larval survival in the field. Larval movement was observed in the laboratory. Silking speed of neonates was faster when either grandparents or parents had fed, while walking speed was faster only when parents had fed. No broad-sense genetic correlation was found between silking speed and walking speed. Broad-sense heritability among feeding histories were not significant for silking speed, but was significantly greater than zero for walking speed when grandparents fed and parents did not. These intergenerational effects could induce complex population dynamics in this species. [source] Age-related white matter lesions are associated with reduction of the apparent diffusion coefficient in the cerebellumEUROPEAN JOURNAL OF NEUROLOGY, Issue 9 2007P. Bugalho Cerebellar apparent diffusion coefficient (ADC) was found to be increased after acute cerebral hemispheric stroke. There are no data on cerebellar ADC changes in patients with chronic, age-related white matter lesions (ARWML). We aimed to determine longitudinal ADC variations on cerebral hemispheric and cerebellar white matter regions of patients with ARWML in order to study relations between ADC changes in both regions. ADC was measured serially (1-year interval) on lesioned periventricular frontal white matter, frontal and parietoccipital normal appearing white matter and middle cerebellar peduncles, on 19 aged patients with ARWML, which also underwent gait assessment. We compared regional ADC at 0 and 1 year and calculated variation percentages for each region. Correlation analysis was made between ADC variation in cerebellar regions and in contralateral hemispheric regions and between cerebellar ADC at 1 year and walking speed. After 1 year, ADC was higher on lesioned periventricular frontal white matter and lower on cerebellar regions. ADC variations on these regions were negatively correlated. Cerebellar ADC measured after 1 year was positively correlated with walking speed. This suggests a link between vascular disease progression inside frontal lesions and ADC reduction in contralateral cerebellar peduncles. Chronic ischemia in frontal white matter could have interrupted frontal-cerebellar circuits, producing hypometabolism in cerebellar regions (and worse performance on motor tasks), decreased perfusion and hence ADC reduction. [source] Ultrasound parameters of bone health and related physical measurement indicators for the community-dwelling elderly in JapanGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 2 2007Wei Sun Deteriorated bone strength, which approaches osteoporosis, increases the likelihood that an elderly person will not able to live independently. However, few data are available pertaining to bone health and various physical objective indicators. The aim of the present study was to objectively assess bone health by quantitative ultrasound (QUS) and identify related physical measurement indicators among the elderly to aid the health promotion strategies in Japan. A cross-sectional study was performed at five welfare centers for the aged in the suburban area of Takatsuki city, Japan. Subjects comprised community-dwelling persons (134 men, 240 women) aged ,60 years and registered at welfare centers. QUS of the right-heel was conducted and recorded as stiffness index (SI). Physical factors including body components (fat and muscle mass), handgrip strength, daily physical activity, daily walking steps, maximum and usual walking speed and maximum bite force were examined objectively during the period May,June 2005. SI in women was lower than that in men (P < 0.01) and decreased significantly with age (P < 0.01). The SI correlated with six physical items in men and with all items in women. Multiple linear regression analysis showed that muscle mass, usual walking speed and maximum bite force were the strongest physical indicators of male SI; and muscle mass, maximum walking speed and maximum bite force were the strongest indicators of female SI. Muscle training, daily walking exercise and oral health care should be included in health promotion programs for the bone health of elderly women and men in Japan. [source] Depression status as a reliable predictor of functional decline among Japanese community-dwelling older adults: a 12-year population-based prospective cohort studyINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 11 2009Hajime Iwasa Abstract Objective This study aimed to examine a longitudinal relationship between depression status and functional decline among Japanese community-dwelling older adults, using a 12-year population-based, prospective cohort study design. Method A total of 710 men and women, aged 65 years and over, participated in the study. Katz's Index and the Tokyo Metropolitan Institute of Gerontology Index of Competence were used to measure the functional capacities of basic activities of daily living (BADL) and higher-level competence, respectively. For the purpose of analysis, a decline in each subscale of functional capacity during the follow-up period were used as outcome variables; depression status assessed by the Japanese version of the 30-item Geriatric Depression Scale (GDS), with a cut-off of 11, was used as an independent variable; and age, gender, education level, history of chronic disease, hospitalization, smoking, physical activity, living alone, hearing problems, physical pain, dietary habits, and usual walking speed at baseline were used as covariates. Results Use of the multivariate Cox proportional hazards model adjusted for potential confounders showed that depression status was significantly and independently associated with BADL decline (risk ratio (RR),=,1.46, 95% confidence interval (CI): 1.13,1.89) and with higher-level competence decline (RR,=,1.56, 95% CI: 1.18,2.04). Conclusion Our study found an independent relationship between depression status and longitudinal change in functional capacity among community-dwelling older individuals, suggesting that depression status is a reliable predictor of functional decline (both of BADL decline and higher-level competence decline) in older adults. Copyright © 2009 John Wiley & Sons, Ltd. [source] Physical Performance and Subsequent Disability and Survival in Older Adults with Malignancy: Results from the Health, Aging and Body Composition StudyJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 1 2010Heidi D. Klepin MD OBJECTIVES: To evaluate objective physical performance measures as predictors of survival and subsequent disability in older patients with cancer. DESIGN: Longitudinal cohort study. SETTING: Health, Aging and Body Composition (Health ABC) Study. PARTICIPANTS: Four hundred twenty-nine individuals diagnosed with cancer during the first 6 years of follow-up of the Health ABC Study. MEASUREMENTS: The associations between precancer measures of physical performance (20-m usual gait speed, 400-m long-distance corridor walk (LDCW), and grip strength) and overall survival and a short-term outcome of 2-year progression to disability or death were evaluated. Cox proportional hazards and logistic regression models, stratified for metastatic disease, respectively, were used for outcomes. RESULTS: Mean age was 77.2, 36.1% were women, and 45.7% were black. Faster 20-m usual walking speed was associated with a lower risk of death in the metastatic group (hazard ratio=0.89, 95% confidence interval (CI)=0.79,0.99) and lower 2-year progression to disability or death in the nonmetastatic group (odds ratio (OR)=0.77, 95% CI=0.64,0.94). Ability to complete the 400-m LDCW was associated with lower 2-year progression to disability or death in the nonmetastatic group (OR=0.24, 95% CI=0.10,0.62). There were no associations between grip strength and disability or death. CONCLUSION: Lower extremity physical performance tests (usual gait speed and 400-m LDCW) were associated with survival and 2-year progression to disability or death. Objective physical performance measures may help inform pretreatment evaluations in older adults with cancer. [source] High Oxidative Stress Is Correlated with Frailty in Elderly ChineseJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2009I-Chien Wu MD OBJECTIVES: To evaluate the relationship between oxidative stress and frailty in elderly people. DESIGN: Cross-sectional study. SETTING: Community and hospital-based outpatient clinic. PARTICIPANTS: Ninety participants aged 65 and older. MEASUREMENTS: Frailty status was determined according to the presence of weak handgrip strength, weight loss, slow walking speed, exhaustion, and low activity level and was classified as frail (,3 criteria), prefrail (1 or 2 criteria), or robust (0 criteria). An oxidative stress marker (serum 8-hydroxy-2,-deoxyguanosine, 8-OHdG), metabolic markers (body mass index, waist,hip ratio, serum lipids, glucose, and albumin), an inflammatory marker (serum high-sensitivity C-reactive protein, hs-CRP), demographic information, and comorbidities (diabetes mellitus, hypertension, congestive heart failure, osteoarthritis, overweight or obesity, impaired fasting plasma glucose, renal insufficiency, and depression) were assessed. RESULTS: Of the 90 participants, 21 (23.3%) were frail, 56 (62.2%) were prefrail, and 13 (14.4%) were robust. Frail subjects had higher median (range) serum 8-OHdG (2.5 ng/mL (1.5,6.2 ng/mL) vs 2.3 ng/mL (0.5,8.1 ng/mL) and 1.0 ng/mL (0.5,5.3 ng/mL)) and serum hs-CRP (2.5 mg/L (0.3,32.1 mg/L) vs 1.8 mg/L (0.3,50.5 mg/L) and 1.7 mg/L (0.3,4.0 mg/L)) levels, lower mean±standard deviation serum albumin levels (4.1±0.4 g/dL vs 4.4±0.4 g/dL and 4.6±0.2 g/dL) and higher mean waist,hip ratios (0.96±0.11 vs 0.91±0.07 and 0.89±0.05)) than prefrail and robust subjects, respectively (P<.05 for all). In multivariable regression analysis, high serum 8-OHdG level was still significantly associated with frailty after adjusting for age, smoking status, comorbidities, waist,hip ratio, serum albumin level, and hs-CRP level. CONCLUSION: High oxidative stress, characterized by high serum 8-OHdG level, was independently associated with frailty in the selected sample of elderly Chinese. [source] Predictors of Interleukin-6 Elevation in Older AdultsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2009Shuhan Zhu BS OBJECTIVES: To investigate the characteristics of older adults who develop high interleukin-6 (IL-6) levels at 3-year follow-up. DESIGN: Population-based study of adults living in Tuscany, Italy. SETTING: Community. PARTICIPANTS: Adults aged 65 and older and were selected for this study. Of 1,155 baseline participants aged 65 and older, 741 had IL-6 measurements at baseline and 3-year follow-up. MEASUREMENTS: The uppermost quartile of IL-6 was used as the threshold for defining high IL-6 (,4.18 pg/mL). Serum IL-6 levels were assessed using enzyme immunoassay. RESULTS: Of the 581 participants with IL-6 levels less than 4.18 pg/mL at baseline, 106 (18.2%) had developed high IL-6 at follow-up. Although women had lower IL-6 levels at baseline than men, the risk of developing high IL-6 did not differ according to sex. High adiposity, defined as a body mass index of 30.0 kg/m2 or higher (odds ratio (OR)=2.63, 95% confidence interval (CI)=1.40,4.96), and large waist circumference, defined as 102 cm or greater for men and 88 cm or greater for women (OR=2.05, 95% CI=1.24,3.40), were significant predictors of developing high IL-6 at follow-up. Other significant predictors were presence of three or more chronic diseases (OR=3.66, 95% CI=1.54,8.70), higher baseline IL-6 (OR=1.82, 95% CI=1.39,2.38) and higher white blood cell count (OR=1.24, 95% CI=1.06,1.45). Faster walking speed associated with decreased risk of progressing to elevated IL-6 (OR=0.83, 95% CI=0.74,0.92). CONCLUSION: Older age, greater adiposity, slower walking speed, higher disease burden, and higher white blood cell count were associated with greater risk of IL-6 elevation over a 3-year period. Future research should target older adults with these characteristics to prevent progression to a proinflammatory state. [source] Changes in Muscle Mass, Muscle Strength, and Power but Not Physical Function Are Related to Testosterone Dose in Healthy Older MenJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 11 2008Thomas W. Storer PhD OBJECTIVES: To examine the effect of graded doses of testosterone on physical function and muscle performance in healthy, older men. DESIGN: Randomized, double-blind, placebo-controlled clinical trial. SETTING: General clinical research center. PARTICIPANTS: Community-dwelling healthy men aged 60 to 75 (N=44). INTERVENTION: Monthly treatment with a gonadotropin-releasing hormone agonist plus 25, 50, 125, or 300 mg/wk of intramuscular injections of testosterone enanthate for 20 weeks. MEASUREMENTS: Skeletal muscle mass (SMM) was estimated using dual-energy X-ray absorptiometry. Leg press strength was measured by one repetition maximum, leg power by Nottingham Leg Rig, and muscle fatigability by repetitions to failure in the leg press exercise. Stair climbing, 6-meter and 400-meter walking speed, and a timed-up-and-go (TUG) test were used to assess physical function. RESULTS: Significant testosterone dose- and concentration-dependent increases were observed in SMM (P<.001) and maximal strength (P=.001) but not muscle fatigability. Leg power also increased dose-dependently (P=.048). In contrast, changes in self-selected normal and fast walking speed over 6 or 400 meters, stair climbing power, and time for the TUG were not significantly related to testosterone dose, testosterone concentrations, or changes in muscle strength or power, or SMM. CONCLUSION: Testosterone administration was associated with dose-dependent increases in SMM, leg strength, and power but did not improve muscle fatigability or physical function. The observation that physical function scores did not improve linearly with strength suggests that these high-functioning older men were already in the asymptotic region of the curve describing the relationship between physical function and strength. [source] Relationship Between Frailty and Cognitive Decline in Older Mexican AmericansJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 10 2008Rafael Samper-Ternent MD OBJECTIVES: To examine the association between frailty status and change in cognitive function over time in older Mexican Americans. DESIGN: Data used were from the Hispanic Established Population for the Epidemiological Study of the Elderly. SETTING: Five southwestern states: Texas, New Mexico, Colorado, Arizona, and California. PARTICIPANTS: One thousand three hundred seventy noninstitutionalized Mexican-American men and women aged 65 and older with a Mini-Mental State Examination (MMSE) score of 21 or higher at baseline (1995/96). MEASUREMENTS: Frailty, defined as three or more of the following components: unintentional weight loss of more than 10 pounds, weakness (lowest 20% in grip strength), self-reported exhaustion, slow walking speed (lowest 20% in 16-foot walk time in seconds), and low physical activity level (lowest 20% on Physical Activity Scale for the Elderly score). Information about sociodemographic factors, MMSE score, medical conditions (stroke, heart attack, diabetes mellitus, arthritis, cancer, and hypertension), depressive symptoms, and visual impairment was obtained. RESULTS: Of the 1,370 subjects, 684 (49.9%) were not frail, 626 (45.7%) were prefrail (1,2 components), and 60 (4.4%) were frail (,3 components) in 1995/96. Using general linear mixed models, it was found that frail subjects had greater cognitive decline over 10 years than not frail subjects (estimate=,0.67, standard error=0.13; P<.001). This association remained statistically significant after controlling for potential confounding factors. CONCLUSION: Frail status in older Mexican Americans with MMSE scores of 21 or higher at baseline is an independent predictor of MMSE score decline over a 10-year period. Future research is needed to establish pathophysiological components that can clarify the relationship between frailty and cognitive decline. [source] Association Between Sleep and Physical Function in Older Men: The Osteoporotic Fractures in Men Sleep StudyJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2008Thuy-Tien L. Dam MD OBJECTIVES: To determine whether sleep quality is associated with physical function in older men. DESIGN: Cross-sectional. SETTING: Six U.S. centers. PARTICIPANTS: Two thousand eight hundred sixty-two community-dwelling men. MEASUREMENTS: Total hours of nighttime sleep (TST), wake after sleep onset (WASO), sleep latency (SL), and sleep efficiency (SE) measured using actigraphy; sleep stage distribution, respiratory disturbance index (RDI), and hypoxia measured using polysomnography; measures of physical function: grip strength, walking speed, chair stand, and narrow walk. RESULTS: In age-adjusted models, <6 or >8 hours TST, SE less than 80%, WASO of 90 minutes or longer, RDI of 30 or greater, and hypoxia were associated with poorer physical function. (Mean grip strength was 2.9% lower and mean walking speed was 4.3% lower in men with WASO ,90 minutes than men with WASO <90 minutes.) After adjusting for potential covariates, differences in grip strength and walking speed remained significantly associated with WASO of 90 minutes or longer, SE less than 80%, and hypoxia but not with TST or RDI of 30 or greater. CONCLUSION: Greater sleep fragmentation and hypoxia are associated with poorer physical function in older men. [source] Frailty in Older Mexican AmericansJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2005Kenneth J. Ottenbacher PhD Objectives: To identify sociodemographic characteristics and health performance variables associated with frailty in older Mexican Americans. Design: A prospective population-based survey. Setting: Homes of older adults living in the southwest. Participants: Six hundred twenty-one noninstitutionalized Mexican-American men and women aged 70 and older included in the Hispanic Established Populations for Epidemiologic Study of the Elderly participated in a home-based interview. Measurements: Interviews included information on sociodemographics, self-reports of medical conditions (arthritis, diabetes mellitus, heart attack, hip fracture, cancer, and stroke) and functional status. Weight and measures of lower and upper extremity muscle strength were obtained along with information on activities of daily living and instrumental activities of daily living. A summary measure of frailty was created based on weight loss, exhaustion, grip strength, and walking speed. Multivariable linear regression identified variables associated with frailty at baseline. Logistic regression examined variables predicting frailty at 1-year follow-up. Results: Sex was associated with frailty at baseline (F=4.28, P=.03). Predictors of frailty in men included upper extremity strength, disability (activities of daily living), comorbidities, and mental status scores (Nagelkerke coefficient of determination (R2)=0.37). Predictors for women included lower extremity strength, disability (activities of daily living), and body mass index (Nagelkerke R2=0.29). At 1-year follow-up, 83% of men and 79% of women were correctly classified as frail. Conclusion: Different variables were identified as statistically significant predictors of frailty in Mexican-American men and women aged 70 and older. The prevention, development, and treatment of frailty in older Mexican Americans may require consideration of the unique characteristics of this population. [source] Chronic Cytomegalovirus Infection and Inflammation Are Associated with Prevalent Frailty in Community-Dwelling Older WomenJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 5 2005Heidi N. Schmaltz MDCM Objectives: To evaluate the association between asymptomatic chronic cytomegalovirus (CMV) infection and the frailty syndrome and to assess whether inflammation modifies this association. Design: Cross-sectional analysis. Setting: Women's Health and Aging Study I & II, Baltimore, Maryland. Participants: Seven hundred twenty-four community-dwelling women aged 70 to 79 with baseline measures of CMV, interleukin-6 (IL-6), and frailty status. Measurements: CMV serology and IL-6 concentrations were measured using enzyme-linked immunosorbent assay. Frailty status was based on previously validated criteria: unintentional weight loss, weak grip strength, exhaustion, slow walking speed, and low level of activity. Frail women had three or more of the five components, prefrail women had one or two components, and women who were not frail had none of the components. Multinomial logistic regression adjusted for potential confounders. Results: Eighty-seven percent of women were CMV seropositive, an indication of chronic infection. CMV was associated with prevalent frailty, adjusting for age, smoking history, elevated body mass index, diabetes mellitus, and congestive heart failure (CMV frail adjusted odds ratio (AOR)=3.2, P=.03; CMV prefrail AOR=1.5, P=.18). IL-6 interacted with CMV, significantly increasing the magnitude of this association (CMV positive and low IL-6 frail AOR=1.5, P=.53; CMV positive and high IL-6 frail AOR=20.3, P=.007; CMV positive and low IL-6 prefrail AOR=0.9, P=.73; CMV positive and high IL-6 prefrail AOR=5.5, P=.001). Conclusion: Chronic CMV infection is associated with prevalent frailty, a state with increased morbidity and mortality in older adults; inflammation enhances this effect. Further prospective studies are needed to establish a causal relationship between CMV, inflammation, and frailty. [source] Low Serum Vitamin D Does Not Predict New Disability or Loss of Muscle Strength in Older WomenJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 5 2002René Verreault MD OBJECTIVES: To determine whether serum levels of 25-hydroxyvitamin D (25(OH)D) and parathyroid hormone (PTH) predict accelerated decline in muscular strength or onset of new disability in mobility and upper extremity functioning over a 3-year follow-up. DESIGN: A community-based prospective cohort study. PARTICIPANTS: Six hundred twenty-eight moderately to severely disabled women aged 65 and older living in the community. MEASUREMENTS: Subjects were divided into three groups of baseline 25(OH)D serum levels (deficiency: <25 nmol/L; low normal: 25,52 nmol/L; high normal: ,53 nmol/L) and into tertiles of PTH levels. Objective performance measures (hip flexor, knee extensor, and grip strengths; walking speed; and time for repeated chair stands) and disability in activities involving mobility and upper extremity function were assessed at baseline and every 6 months for 3 years. Decline in performance measures and onset of new disability were compared between 25(OH)D and PTH groups using random effects models and proportional hazards models, respectively, while adjusting for age, race, education, body mass index, baseline performance, and chronic conditions. RESULTS: The annual rate of decline over 3 years in muscular strength, walking speed, and time to perform repeated chair stands was similar across 25(OH)D groups. We observed a nonsignificantly faster decline in proximal muscle strength and walking speed with increasing PTH levels. There was no association for either measure between serum levels and the risk of incident disability in activities relating to mobility and upper extremity function. CONCLUSION: This study does not support the hypothesis that vitamin D deficiency is associated with loss in muscular strength and decline in mobility and upper extremity functioning over time in older women who were moderately to severely disabled at baseline. [source] Gait Variability in Community-Dwelling Older AdultsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 12 2001Jennifer S. Brach PhD OBJECTIVES: To describe gait variability at usual and fast walking speeds in community-dwelling older adults and to describe the effects of increasing gait speed on gait variability. DESIGN: Cross-sectional, descriptive study. SETTING: The Cardiovascular Health Study at the University of Pittsburgh. PARTICIPANTS: Ninety-five community-living older adults, 54 women and 41 men, age 65 and older (mean age ± standard deviation 79.4 ± 3.37). MEASUREMENTS: Gait measured at participant's usual and fast walking speed collected using an instrumented walkway. Step-length and step-width variability were determined using the coefficient of variation. CONCLUSIONS: Step-length and step-width variability have opposite associations with gait speed in older adults. Improvement in step-length and step-width variability with attempted acceleration might be a key factor to examine in future studies of disability risk and therapeutic interventions. [source] The role of plant trichomes and caterpillar group size on growth and defence of the pipevine swallowtail Battus philenorJOURNAL OF ANIMAL ECOLOGY, Issue 6 2001James A. Fordyce Summary 1The California population of the pipevine swallowtail Battus philenor is a specialist on the Dutchman's pipe Aristolochia californica, an endemic vine that is densely covered with trichomes. Populations of B. philenor outside California use other Aristolochia species that are largely glabrous. The average clutch size of the pipevine swallowtail is larger in California compared with populations elsewhere and larvae feed gregariously until late in the third instar. 2In the field, caterpillars consumed more leaf material and showed preference for portions of leaves with trichomes removed. However, large groups of caterpillars were consistently observed feeding on the apical portion of the plant, where trichome density was highest. Smaller groups of caterpillars were observed feeding more often on mature leaves on the lower portions of the plant, where trichome density was lower. 3Laboratory experiments showed that the walking speed of a commonly observed predator, larvae of the green lacewing Chrysopa carnea, was reduced as trichome density increased. Furthermore, lacewing search efficiency and capture rate of a model prey item were compromised by high trichome density. 4In an additional field experiment, no difference was found in the percentage mortality of groups of four and 12 caterpillars. However, growth rate of the larger group was accelerated by 25% compared with smaller groups. In an experiment using a ladybird beetle larva Hippodamia convergens as the predator, no difference was observed in absolute mortality of caterpillars, suggesting that group size does not function directly as a defence against predators. 5First instar caterpillars are most vulnerable to predators, thus feeding in larger groups may benefit caterpillars by accelerating growth. Feeding in large groups may also be an effective strategy for B. philenor to overcome plant trichomes and feed on portions of the plant conducive to faster development. However, feeding on areas with dense trichomes does not appear to provide larvae with a refuge from predators. [source] Temperature influences walking speed and walking activity of Trichogramma brassicae (Hym., Trichogrammatidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 6 2001B. P. Suverkropp Walking speeds and walking activities (walking time divided by total time) of Trichogramma brassicae were determined at 12, 16, 20 and 25°C. Walking speed was measured during a 5-min period, and walking activity over a 4-day period. Both walking speed and walking activity were strongly influenced by temperature. Walking speed increased linearly with the temperature and was twice as high at 20 as at 12°C. At 25°C, walking activity was high during the whole day, at 20 and 16°C it decreased during the afternoon, whereas at 12°C the wasps became most active only at noon or later. At low temperatures, there was a strong individual variation in walking activity. At 25°C, T. brassicae was active most of the time, so the area searched per time unit can only increase at temperatures above 25°C if walking speed increases. At temperatures below 20°C, searching was more restricted by low walking activity than by low walking speed. Even disregarding other effects of temperature, the reduction in walking speed and walking activity at suboptimal temperatures means that T. brassicae can only search half of the area at 20°C, and only one-seventh at 15°C that it can search at 25°C. [source] Non-target habitat exploitation by Trichogramma brassicae (Hym. Trichogrammatidae): what are the risks for endemic butterflies?AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2003D. Babendreier Abstract 1,Trichogramma brassicae Bezdenko is inundatively released against the European corn borer in Switzerland. Because parasitoids dispersing from the release fields might pose a threat to native butterflies, the searching efficiency of T. brassicae was investigated in nontarget habitats. 2,In field studies, T. brassicae was released at rates of 120 000 females/ha. Parasitism of sentinel Ephestia kuehniella egg clusters was 1.6,3.6% in meadows and 2.0,4.0% in flower strips. The respective figures were 57.6,66.7% and 19.2,46.9% in maize, significantly higher than the parasitism rates in the nontarget habitats. Experiments carried out in small field cages confirmed these results: Again, significantly higher parasitism rates were found in maize compared to meadows and flower strips, and also compared to hedgerows (in sleeve cages). 3,To elucidate potential factors underlying the low searching efficiency in nontarget habitats, the behaviour of individual T. brassicae females was investigated on four meadow plants comparatively to maize and a filter paper control. Mean (±SE) walking speed on maize was 2.2 ± 0.2 mm/s, similar to three of the plants tested and filter paper but significantly higher than on Trifolium pratense (0.85 mm/s). A higher turning rate was found on T. pratense, Viola wittrockiana and Plantago lanceolata, in contrast to the longer leaved maize and Alopecurus pratensis. The number of wasps leaving the plant within the observation period differed significantly between plant species, and was twice as high for T. pratense (and the filter paper control) compared to the other plant species. 4,In a choice experiment carried out in a climate cabinet with all five host plant species in cages, we obtained the highest parasitism rates on maize and the lowest parasitism on T. pratense, thus confirming the behavioural observations. 5,In conclusion, there is evidence for a decreased searching efficiency on plants in nontarget habitats compared to maize. However, the data explain only part of the differences found between parasitism in maize compared to nontarget habitats. Other factors, such as the structural complexity of a habitat, may also play a role. We conclude that the risk for butterfly populations in the tested nontarget habitat due to mass released T. brassicae is low. [source] Pes planovalgus in RA: a descriptive and analytical study of foot function determined by gait analysisMUSCULOSKELETAL CARE, Issue 1 2003Deborah E. Turner BSc SRCh Abstract Objective: To compare gait and foot function between rheumatoid arthritis (RA) patients with painful pes planovalgus deformity and healthy age- and sex-matched adults. Methods: Gait analysis was undertaken in 23 RA patients (14 female and 9 male, mean age 52.3 years, mean disease duration 6.6 years) and 23 healthy adults (14 female and 9 male, mean age 49.5 years). Gait measurements included temporal and spatial parameters, plantar pressures and three-dimensional (3D) kinematics at the ankle joint complex (AJC). The mean differences between the groups and associated confidence intervals were calculated using the t distribution. Results: RA patients showed longer gait cycle (mean difference 0.15 sec and 0.14 sec for right and left limbs, respectively) and double-limb support times (mean difference 8.3% and 7.9% for right and left limbs, respectively), shorter stride length (mean difference ,0.31 m for right and left limbs), slower walking speed (mean difference ,0.39 m/sec) and lower cadence (mean difference ,16.6 steps/min). In comparison with the normal group, RA patients had greater AJC dorsi/plantarflexion range of motion (ROM) (mean difference 5.7 °) and inversion/eversion ROM (mean difference 2.9 °). The frontal plane position of the AJC was more everted at specific stance periods (mean difference at heel strike ,2.4 ° and at midstance ,4.0°). Furthermore, both the peak eversion (mean difference ,4.1 °) and summated eversion motion as a function of time (mean difference ,313.9 °) were greater in the RA group. The pes planovalgus foot in RA was characterized by increases in peak pressure (mean difference 34.3 kPa), pressure,time integral (mean difference 18.2 kPa.sec), peak force (mean difference 1.7 N), force,time integral (mean difference 0.7 N.sec), contact time (mean difference 9.8% roll over process) and contact area (mean group difference 3.4 cm,2) in the medial midfoot. Further changes in the load pattern in the forefoot were observed in the RA patients, namely increases in the peak pressure (mean difference 96.4 kPa), pressure,time integral (mean difference 58.4 kPa.sec), and contact area (mean difference 1.7 cm,2) in the medial forefoot region and reduction in contact area (mean difference ,3.9 cm,2), peak force (mean difference ,7.2 N) and force,time integral (mean difference ,1.6 N.sec) in the lateral forefoot. Conclusions: Painful pes planovalgus deformity in RA is associated with global changes in gait, and localized structural and functional changes in the foot which can be accurately measured using clinical gait analysis. Copyright © 2003 Whurr Publishers Ltd. [source] Clinical Application of Peroneal Nerve Stimulator System Using Percutaneous Intramuscular Electrodes for Correction of Foot Drop in Hemiplegic PatientsNEUROMODULATION, Issue 4 2006Yoichi Shimada MD Abstract Objective., To assess the orthotic effect of a functional electrical stimulation device (Akita Heel Sensor System; AHSS) in the treatment of hemiplegic gait with foot drop. Materials and Methods., In the AHSS, a heel sensor is attached to a small plastic heel brace, and the peroneal nerve is stimulated via percutaneous intramuscular electrodes. During the swing phase of the hemiplegic gait, the common peroneal nerve is stimulated by the AHSS. Eight patients in chronic stages of hemiplegia participated in this study. Walking speeds and step cadences on a 10-m course were compared between walking with stimulation and walking without stimulation. Results., Mean walking speed (± SD) was 0.50 ± 0.26 m/sec without stimulation and 0.64 ± 0.31 m/sec with stimulation. The mean percentage increase in walking speed with stimulation was 30.1%. Mean step cadence was 31 ± 7 steps/10 m without stimulation and 27 ± 7 steps/10 m with stimulation. By correcting foot drop, the AHSS significantly increased walking speed and decreased cadence (p < 0.05). Conclusion., The AHSS can significantly improve walking in hemiplegic patients with foot drop. [source] The Effects of Pain and Depression on Physical Functioning in Elderly Residents of a Continuing Care Retirement CommunityPAIN MEDICINE, Issue 4 2000Jana M. Mossey PhD Objective., Explore the relationships between pain, depression, and functional disability in elderly persons. Design.,A cross-sectional, observational study of 228 independently living retirement community residents. Methods., Self-report measures of pain (adaptation of McGill Pain Questionnaire), depression (Geriatric Depression Scale [GDS]) and physical functioning (Physical performance difficulties, activities of daily living [ADL], independent activities of daily living [IADL], and 3-meter walking speed) were employed. Outcome Measures.,Physical functioning variables were dichotomized. Individuals in the lowest quartiles of functional performance and of walking speed were contrasted to all others; for ADL and IADL, those needing some help were compared with those independent in activities. Results., Pain and depression levels were strongly related to physical performance; depression levels were related to ADL and walking speed. In multivariate analyses, an interaction effect was observed where the effects of pain were a function of level of depression. Individuals reporting activity-limiting pain and slightly elevated depressive symptom levels, sub-threshold depression, or major depression were significantly more likely (AOR 7.8; 95% CI, 3.07,20.03) than non-depressed persons to be in the lowest quartile of self-reported physical performance. Conclusions., While both pain and depression level affect physical performance, depressive symptoms rather than pain appear the more influential factor. When seeing elderly patients, identifying, evaluating, and treating both pain complaints and depressive symptoms and disorders may reduce functional impairment. [source] Mechanical and neural stretch responses of the human soleus muscle at different walking speedsTHE JOURNAL OF PHYSIOLOGY, Issue 13 2009Neil J. Cronin During human walking, a sudden trip may elicit a Ia afferent fibre mediated short latency stretch reflex. The aim of this study was to investigate soleus (SOL) muscle mechanical behaviour in response to dorsiflexion perturbations, and to relate this behaviour to short latency stretch reflex responses. Twelve healthy subjects walked on a treadmill with the left leg attached to an actuator capable of rapidly dorsiflexing the ankle joint. Ultrasound was used to measure fascicle lengths in SOL during walking, and surface electromyography (EMG) was used to record muscle activation. Dorsiflexion perturbations of 6 deg were applied during mid-stance at walking speeds of 3, 4 and 5 km h,1. At each walking speed, perturbations were delivered at three different velocities (slow: ,170 deg s,1, mid: ,230 deg s,1, fast: ,280 deg s,1). At 5 km h,1, fascicle stretch amplitude was 34,40% smaller and fascicle stretch velocity 22,28% slower than at 3 km h,1 in response to a constant amplitude perturbation, whilst stretch reflex amplitudes were unchanged. Changes in fascicle stretch parameters can be attributed to an increase in muscle stiffness at faster walking speeds. As stretch velocity is a potent stimulus to muscle spindles, a decrease in the velocity of fascicle stretch at faster walking speeds would be expected to decrease spindle afferent feedback and thus stretch reflex amplitudes, which did not occur. It is therefore postulated that other mechanisms, such as altered fusimotor drive, reduced pre-synaptic inhibition and/or increased descending excitatory input, acted to maintain motoneurone output as walking speed increased, preventing a decrease in short latency reflex amplitudes. [source] Temperament assessments of lactating cows in three contexts and their applicability as management traitsANIMAL SCIENCE JOURNAL, Issue 6 2004Katsuji UETAKE ABSTRACT The applicability of three behavioral assessments of lactating cows as management traits was verified. Flight responses to an approaching human (flight starting and walking distances, and flight walking speed) at pasture, entrance order into the milking parlour and step-kick behavior to cup attachment were observed for 713 subject cows in six Australasian dairy farms. On all farms, cows were kept at pasture without any barn housing. Flight responses were measured once, and other assessments were recorded repeatedly for each subject cow. A principal component analysis was performed to verify whether these assessments appear to measure the same trait. A two-way anova and correlation analyses were then used to test whether obtained principal components were affected by farm, age and milking stage of cows. Australian and some Japanese herd management systems were compared for flight distance using a one-way anova and a multiple comparison test. Three behavioral assessments clustered in different principal components, indicating that these assessments did not appear to measure the same trait. Factor scores of four principal components were affected by farm (all, P < 0.01), and the scores of principal component 1, interpreted as fear of humans (r = ,0.16, P < 0.01), and component 2, interpreted as aversion to cup attachment (r = ,0.28, P < 0.01), were moderately correlated with age. These results emphasize the necessity of data standardization to reduce the non-genetic variation resulting from these two affectors. The flight distance at pasture of herds in Australia (6.06 ± 2.85 m) was significantly (P < 0.05) different from the flight distances measured in paddocks (1.50 ± 0.82 m) and free-stall barns (1.22 ± 1.09 m) in Japan. However, mean distances were not different between the Australian herds at pasture and the Japanese herds at pasture in tie-stall barns (3.96 ± 2.16 m) or in a free-stall barn (4.03 ± 1.79 m). This difference could be a result of the fact that only a single measurement was made, so that repeated measurement might improve the usefulness of flight distance as a management trait. In conclusion, it was verified that step-kick behavior to cup attachment and flight responses to human approach were, although they have some affectors, applicable as objective management traits in lactating cows. [source] White matter lesions volume and motor performances in the elderly,ANNALS OF NEUROLOGY, Issue 6 2009Aïcha Soumaré MSc Objectives To investigate the cross-sectional and longitudinal associations between performance-based measures of motor function and volume of white matter lesions (WMLs), and to examine the influence of the localization of these lesions. Methods At baseline, motor performances (maximum walking speed, Tinetti gait and balance subscales) were assessed in 1,702 subjects aged 80 years or younger from the Dijon (France), France center of the Three-City study. Volumes of WMLs lesions (total, periventricular, deep) were measured using an automated method of tissue segmentation and quantification of lesion size. At 8-year follow-up, walking speed was evaluated in 1,086 subjects. Results At baseline, mean and 95% confidence interval (CI) walking speed was lower in subjects with total volumes of WMLs ,90th percentile (1.50 [1.45,1.55] m/s) than in subjects with lower volumes (1.56 [1.55,1.58] m/s; p = 0.004). Baseline total volumes of WMLs above the 90th percentile predicted walking speed decline during follow-up (odds ratio [95% CI] for having the greatest walking speed decline = 2.3 [1.3,4.1], p = 0.006). Moreover, high volumes of periventricular but not deep WMLs were associated with slower walking speed at baseline (p = 0.005) and over time (p = 0.001), and with lower Tinetti gait subscore (p = 0.02). Interpretation Our study shows a cross-sectional and longitudinal association between high total volumes of WMLs, in particular volumes above the 90th percentile, and impaired mobility. These associations were independent of several confounders, including cognition, and were mainly accounted for by volumes of periventricular WMLs. These findings support the hypothesis of a vascular contribution to motor decline in the elderly. Ann Neurol 2009;65:706,715 [source] | |||||||||||||||||||||||||||||||