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PubMed2006

The validation of a novel activity monitor in the measurement of posture and motion during everyday activities.

BACKGROUND: Accurate measurement of physical activity patterns can be used to identify sedentary behaviour and may facilitate interventions aimed at reducing inactivity. OBJECTIVE: To evaluate the activPAL physical activity monitor as a measure of posture and motion in everyday activities using observational analysis as the criterion standard. METHODS: Wearing three activPAL monitors, 10 healthy participants performed a range of randomly assigned everyday tasks incorporating walking, standing and sitting. Each trial was captured on a digital camera and the recordings were synchronised with the activPAL. The time spent in different postures was visually classified and this was compared with the activPAL output. RESULTS: Intraclass correlation coefficients (ICC 2,1) for interdevice reliability ranged from 0.79 to 0.99. Using the Bland and Altman method, the mean percentage difference between the activPAL monitor and observation for total time spent sitting was 0.19% (limits of agreement -0.68% to 1.06%) and for total time spent upright was -0.27% (limits of agreement -1.38% to 0.84%). The mean difference for total time spent standing was 1.4% (limits of agreement -6.2% to 9.1%) and for total time spent walking was -2.0% (limits of agreement -16.1% to 12.1%). A second-by-second analysis between observer and monitor found an overall agreement of 95.9%. CONCLUSION: The activPAL activity monitor is a valid and reliable measure of posture and motion during everyday physical activities.

Activities of Daily Living↗
PubMed1987

Selected sleep disturbances in school children reported by parents: prevalence, interrelationships, behavioral correlates and parental attributions.

Epidemiological, behavioral and etiological variables related to sleep disturbances were investigated in a survey of 1695 children in Grades 1 to 12 from 11 randomly selected schools. Sleep-walking, nightmares and sleep-talking were strongly associated with each other as well as to a family history of sleep-walking. Enuresis, however, was not related to the other sleep variables. Socioeconomic status of father was weakly related to enuresis and sleep-talking but not to sleep-walking or nightmares. Gender was not related to any of the sleep disturbances. The behavioral variables, physical activity, attention, emotional excitability, and feelings easily hurt showed a small association with the sleep disturbances. Parents most frequently attributed causes of sleep-walking and nightmares to over-tiredness and over-excitement. As well, parents' comments indicated that they tend to associate specific events such as illness or more often, frightening TV content with nightmares, but not sleep-walking.

Adolescent↗
PubMed1996

Serum ferritin and heart disease: the effect of moderate exercise on stored iron levels in postmenopausal women.

OBJECTIVE: To determine the effect of a moderate exercise regimen on stored iron as measured by serum ferritin in previously sedentary postmenopausal women. DESIGN: Randomized assignment to one of three groups: a five day/week walking group (five-day group, n = 27); a three day/week walking group (three-day group, n = 27) or a sedentary group (control group, n = 25). SETTING: Community-based intervention. PARTICIPANTS: Women who were postmenopausal, over 50 years old, sedentary, not on hormone replacement therapy, nonsmokers, physically capable of exercising, without clinical signs of cardiovascular, pulmonary or metabolic disease, and not on medication that would affect iron metabolism. In addition, they had neither donated blood nor been transfused within the previous 12 months. All participants were screened volunteers who had responded to media advertisements. Seventy-nine participants met these criteria. Results are reported for 56 subjects (five-day group, n = 17; three-day group, n = 19; control group, n = 20) who completed the study. Their mean age was 61.3 +/- 5.8 years. INTERVENTION: The five-day group and the three-day group walked an average of 279 +/- 20 and 171 +/- 7 mins/week, respectively. Participants were counselled not to change their dietary intake. MAIN RESULTS: Following 24 weeks of walking, mean serum ferritin decreased significantly in the five-day group (P < 0.03), but not in the three-day group (P < 0.09) compared with controls. CONCLUSIONS: The extent of physical activity required to elicit a decrease in stored iron in postmenopausal women was determined. This may be clinically significant because stored iron increases significantly following menopause and excess stored iron have been cited as risk factors for coronary artery disease.

Exercise↗
PubMed1999

Who walks? Factors associated with walking behavior in disabled older women with and without self-reported walking difficulty.

OBJECTIVES: To determine how severity of walking difficulty and sociodemographic, psychosocial, and health-related factors influence walking behavior in disabled older women. DESIGN: Cross-sectional analyses of baseline data from the Women's Health and Aging Study (WHAS). SETTING: An urban community encompassing 12 contiguous zip code areas in the eastern portion of Baltimore City and part of Baltimore County, Maryland. PARTICIPANTS: A total of 920 moderately to severely disabled community-resident women, aged 65 years and older, identified from an age-stratified random sample of Medicare beneficiaries. MEASUREMENTS: Walking behavior was defined as minutes walked for exercise and total blocks walked per week. Independent variables included self-reported walking difficulty, sociodemographic factors, psychological status (depression, mastery, anxiety, and cognition), and health-related factors (falls and fear of falling, fatigue, vision and balance problems, weight, smoking, and cane use). RESULTS: Walking at least 8 blocks per week was strongly negatively related to severity of walking difficulty. Independent of difficulty level, older age, black race, fatigue, obesity, and cane use were also negatively associated with walking; living alone and high mastery had a positive association with walking. CONCLUSIONS: Even among functionally limited women, sociocultural, psychological, and health-related factors were independently associated with walking behavior. Thus, programs aimed at improving walking ability need to address these factors in addition to walking difficulties to maximize participation and compliance.

Accidental Falls↗
PubMed2006

Aerobic exercise in water versus walking on land: effects on indices of fat reduction and weight loss of obese women.

AIM: It has been suggested, that water exercise is less effective than weight-bearing exercise on land for body fat reduction. METHODS: To test this hypothesis 38 middle-aged obese women (25-47% body fat) participated in a 13 week exercise-diet program to compare the effects of aerobic exercise in water versus walking on land on indices of fat reduction and weight loss changes. Subjects were randomly assigned to 1 of 3 exercise groups: 1) walking on land (WL), 2) swimming (SW) at 27 degrees C water temperature and 3) walking in 29 degrees C water (WW) at the shallow end of a declining pool with the water at navel height. Subjects in the SW group alternated breast-, side-, and backstroke swimming without face immersion. Exercise parameters were kept constant for all three groups. Subjects participated in supervised exercise sessions for 40 min, 4 times a week at 70% of age-predicted maximum heart rate. Subjects were tested before and after the 13-week experimental period. RESULTS: Significant reductions in body weight, (5.9 kg), percent body fat, (3.7%), and skinfold and girth measurements, occurred in all groups. There where no significant differences between groups. CONCLUSIONS: The results of this study indicate that there are no differences in the effect of aerobic activities in the water versus weight-bearing aerobic exercise on land on body composition components as long as similar intensity, duration and frequency are used.

Adult↗
PubMed2001

Metabolic cost of walking with and without a shoe lift on the contralateral foot of an immobilised extended knee.

The purpose of the present study was to determine the metabolic cost of walking with and without a shoe-lift on the contralateral foot of an immobilised extended knee. Eight male subjects were randomly allocated and participated in both the treatment (walking with a 2.5 cm shoe-lift) and control (walking without a shoe-lift) conditions. Cardiac output (Q) and related cardiovascular measurements were analysed to determine the effect of a shoe-lift on central (heart rate (HR); stroke volume (SV)) and peripheral (arteriovenous oxygen difference (a-vO2 diff)) components of oxygen consumption (VO2). A metabolic analyser was used to determine VO2 (ml x kg(-1) x min(-1)), which was converted to oxygen cost (ml x kg(-1) x m(-1)). The shoe-lift had no significant (p > 0.05) effect on VO2 or oxygen cost. There were no significant differences in Q, HR, SV, a-vO2 diff, systemic vascular resistance, carbon dioxide production, respiratory exchange ratio, expired ventilation, tidal volume and respiratory rate between the two walking conditions with and without a shoe-lift. These findings demonstrate that a shoe-lift added to the contralateral foot of an immobilised extended knee does not produce clinically important effects on oxygen cost or efficiency during walking.

Adult↗
PubMed2006

Red blood cell deformability in patients with claudication after pain-free treadmill training.

OBJECTIVES: To assess the effect of pain-free treadmill training on red blood cell deformability and walking distance in patients with claudication. DESIGN: Randomized-controlled trial of exercise training. SETTING: Patients were recruited from the primary care, vascular outpatient clinic. PATIENTS: A total of 60 patients with peripheral arterial occlusive disease (stage II according to Leriche-Fontaine) were randomized into the treadmill program or a control group. Fifty-five patients completed the study (27 in the exercising group and 28 in the control group). INTERVENTIONS: Patients in the exercising group were walking on the treadmill 3 times a week for 3 months. Each session consisted of 1 hour repetitive walking [performed to 85% of the pain-free walking time (PFWT)] was supervised by a qualified physiotherapist. MAIN OUTCOME MEASUREMENTS: Changes in erythrocyte deformability and treadmill walking performance (PFWT, maximal walking time) were assessed in both groups before the study and after 3 months. RESULTS: After 3 months of treadmill training, red blood cell deformability in the exercising group significantly increased (P<0.01). No significant changes were seen in the erythrocyte deformability in the control group. PFWT was prolonged by 102% from 191+/-34 to 386+/-60 seconds (P<0.01), and maximal walking time increased by 49% from 438+/-62 to 656+/-79 seconds (P<0.01) in the exercising group, whereas these changes were insignificant in the control group. CONCLUSIONS: A significant improvement of walking ability over 3 months of pain-free treadmill training is associated with a significant increase in red cell deformability in patients with claudication.

Aged↗
PubMed2002

The short-term effect of a rollator on functional exercise capacity among individuals with severe COPD.

STUDY OBJECTIVES: This study was conducted to examine the short-term effects of using a rollator on functional exercise capacity among individuals with COPD and to characterize which individuals benefit most from its use. DESIGN: Repeated-measures randomized crossover design using the 6-min walk test (6MWT) as the primary outcome measure. SETTING: Respiratory rehabilitation center. PATIENTS: Forty stable subjects who had received a diagnosis of COPD. INTERVENTIONS: Two 6MWTs were performed on each study day. One 6MWT was performed unaided, and the other was performed with a rollator. The order was randomized on the first day and reversed on the second day. RESULTS: Use of the rollator was associated with a significant reduction in dyspnea (p < 0.001) and duration of rest (reduction for the total group, 19 s; and reduction for those who walked < 300 m unaided, 40 s; p = 0.001) during the 6MWT. For subjects who walked < 300 m unaided, there was also a significant improvement in distance walked (p = 0.02). No changes were found for the measures of cardiorespiratory function or gait (p > 0.05). The requirement to rest during an unaided 6MWT was a significant predictor of improved functional exercise capacity with the use of the rollator (p < 0.005). The majority of subjects whose unaided 6MWT distance was < 300 m preferred using the rollator to walking unaided. CONCLUSIONS: Use of a rollator was effective in improving functional exercise capacity by reducing dyspnea and rest duration among stable individuals with severe COPD. Individuals who walked < 300 m and individuals who required a rest during an unaided 6MWT benefited the most from using a rollator in terms of reduced dyspnea, reduced rest time, and improved distance walked.

Aged↗
PubMed2000

Effect of exercise intensity on bone density, strength, and calcium turnover in older women.

PURPOSE: This study examined the effects of 24 wk of high intensity strength training or low intensity walking on lumbar bone mineral density (BMD), muscular strength, and calcium turnover in Australian women either taking hormone replacement therapy (HRT) or not taking HRT. METHODS: A subject pool of 64 women between 45-65 yr and randomly allocated into weights (N = 21), walking (N = 20), weightsHRT (N = 14), and walkingHRT (N = 9) groups completed this study. All subjects trained twice weekly in either a 50-min walking or weight-training program (60-90% IRM). Measurements included maximal isometric knee strength, IRM bench press, IRM squat, isokinetic back strength, lumbar (L2-L4) BMD, serum osteocalcin, and urinary deoxypyridinoline crosslinks (Dpd). RESULTS: No significant group differences in BMD were evident at the completion of training. However, a significant (P < 0.05) within group change was apparent for the walking group since BMD decreased 1.3% below baseline testing. Osteocalcin levels increased significantly (P < 0.05) in the walking (22%) group. Maximal bench press and squat strength improved significantly (P < 0.05) in the weights (25.8% and 37.7%) and weightsHRT (25.4% and 35.7%) groups. The weights group also increased significantly (P < 0.05) in isokinetic back strength (22.2%). CONCLUSION: It was concluded that short-term high intensity resistance training provides an effective means for increasing muscular strength in women between 45 and 65 yr. The training effects on lumbar BMD were not apparent in the present study.

Aged↗
PubMed2001

Comparative effects of cilostazol and other therapies for intermittent claudication.

Many patients with peripheral arterial disease (PAD) have intermittent claudication or problems with ambulation and mobility. Exercise and smoking cessation are primary therapies for claudication, but drug treatment may provide additional benefit. The data supporting use of pentoxifylline for claudication are weak, and pentoxifylline is not generally accepted as efficacious. Cilostazol is a new drug for the treatment of claudication. It appears to modestly benefit walking ability and it has other potentially useful effects, including inhibition of platelet aggregation and beneficial effects on serum lipids. In a randomized, prospective, double-blind trial examining walking ability in patients with PAD with moderate-to-severe claudication, cilostazol was superior to both placebo and pentoxifylline.

Cilostazol↗
PubMed2002

Do baby walkers delay onset of walking in young children?

Baby walkers have been a source of considerable controversy. Some people suggest developmental benefit from their use while others focus on the potential harm that stems from accidents and even suggest developmental delay. This mini-review aimed to determine if use of a baby walker delays affects the onset of walking. The Cochrane library, Embase, CINAHL and Medline were searched for randomized controlled trials (RCTs) and cohort studies, which compared the onset of walking in infants who used baby walkers with a group who did not. Two RCTs and two cohort studies were identified and available for consideration. All of the studies examined the effect of infant walkers on the onset of walking. The results of the two RCTs did not demonstrate a significant effect on the onset of walking. The cohort studies suggest that the use of infant walkers delayed the onset of walking in young children and a pooled analysis of the four studies suggested a delay of between 11 and 26 days. Although the quality of the studies was relatively poor these studies lend no support to the argument that walkers aid the development of walking. The significance of a delay of this magnitude is however unclear. Further work is required to determine whether walkers are an independent causal factor in accidents.

Age Factors↗
PubMed2006

Gluteal taping improves hip extension during stance phase of walking following stroke.

The aim of this study was to determine whether gluteal taping on the affected side improved hip extension during stance phase of walking for persons following stroke. Fifteen subjects who had suffered a stroke months to years previously resulting in mild to moderate gait impairments participated in the study. Their gait was measured under control, sham, and gluteal taping conditions, in random order. For each condition, subjects walked at a self-selected and a fast speed. Hip angle relative to that obtained during quiet standing, step length, stride length and walking velocity were measured. Hip extension increased significantly with gluteal taping (p < 0.05) for both walking speeds at late stance phase of walk compared to sham taping and control. The mean absolute difference between gluteal and control conditions for self-selected velocity was 14.2 degrees (95% CI 8.6 to 19.8) whereas the difference between sham and control conditions was 2.0 degrees (95% CI -2.0 to 6.0). Also, for both speeds, step length on the unaffected side increased significantly with gluteal taping compared with either the control or placebo conditions. The absolute difference between gluteal taping and control conditions at self-selected velocity was 3.3 cm (95% CI 2.2 to 4.3) and between sham and control conditions was 0.6 cm (95% CI -0.8 to 1.9). Affected step length and walking velocity, however, remained unchanged. Lastly, there was no significant difference between the control and sham taping condition for any of the measured variables. Gluteal taping may be a useful adjunct to current rehabilitation gait training strategies.

Case-Control Studies↗
PubMed2003

Vicious walks with a wall, noncolliding meanders, and chiral and Bogoliubov-de Gennes random matrices.

Spatially and temporally inhomogeneous evolution of one-dimensional vicious walkers with wall restriction is studied. We show that its continuum version is equivalent with a noncolliding system of stochastic processes called Brownian meanders. Here the Brownian meander is a temporally inhomogeneous process introduced by Yor as a transform of the Bessel process that is the motion of radial coordinate of the three-dimensional Brownian motion represented in spherical coordinates. It is proved that the spatial distribution of vicious walkers with a wall at the origin can be described by the eigenvalue statistics of Gaussian ensembles of Bogoliubov-de Gennes Hamiltonians of the mean-field theory of superconductivity, which have a particle-hole symmetry. We report that a time evolution of the present stochastic process is fully characterized by the change of symmetry classes from type C to type CI in the nonstandard classes of random matrix theory of Altland and Zirnbauer. The relation between the noncolliding systems of the generalized meanders of Yor, which are associated with the even-dimensional Bessel processes, and the chiral random matrix theory is also clarified.

Journal Article↗
PubMed2004

The effects of 60 minutes of brisk walking per week, accumulated in two different patterns, on cardiovascular risk.

BACKGROUND: Current ACSM guidelines recommend that adults should exercise for 20-60 min on 3-5 days.week(-1) (M.L. Pollock, et al., The recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness, and flexibility in healthy adults. Medicine and Science in Sports and Exercise, 30 (6) (1998) 975-991.). For individuals constrained by a busy lifestyle, an exercise prescription that delivers benefits with the minimum investment of time is attractive. The purpose of the present study, therefore, was to examine the effect of instructing sedentary individuals to undertake 20 min of brisk walking, in two different patterns, 3 days per week, on fitness and other cardiovascular disease (CVD) risk factors. METHODS: Forty-eight subjects (31 women) mean (+/-SD) age 45.7 +/- 9.4 year were randomly assigned to either one 20-min walk (single bout), two 10-min walks (accumulated bouts) 3 days week(-1) for 12-week, or no training (control). Oxygen consumption (VO2), heart rate (HR), and ratings of perceived exertion (RPE) were measured during a 4-stage treadmill test at pre- and post-intervention. Body composition, resting blood pressure and fasting lipoproteins were also assessed. Thirty-two subjects completed the study. RESULTS: There was a significant difference between single-bout and accumulated-bout walkers in the reduction of HR at stages 2 and 3 of the treadmill test from pre- to post-intervention (P < 0.05). There were no differences between groups for changes in VO2 or RPE from pre- to post-intervention. There were also no changes in body mass, adiposity, blood pressure, waist and hip circumferences, or lipid/lipoproteins. CONCLUSION: Brisk walking for 20 min on 3 days of the week fails to alter cardiovascular disease risk factors in previously sedentary adults.

Adult↗
PubMed1982

Infant walkers: developmental tool or inherent danger.

This study investigated the influence of pre-walking practice in an infant walker on the onset time of independent walking. 15 pairs of twins were randomly divided into experimental and control groups. Only the experimental group was exposed to an infant walker. This group spent a minimum of 1 hr. per day in an infant walker from 4 mo. of age until the onset of bipedal locomotion. The infants in the control group were not placed in infant walkers. A one-way analysis of variance indicated there was no significant difference between the mean ages of initial walking for the experimental and control groups. The use of the infant walker did not influence the onset of independent walking.

Child Development↗
PubMed1992

Correlates of change in walking for exercise: an exploratory analysis.

This study was designed to identify correlates of change in walking for exercise. Respondents to a random sample mailed exercise survey were asked to complete a follow-up questionnaire 24 months after the first. Responses were obtained from 1,739 adults, reflecting an 86.6% return rate. Nonrespondents did not differ from respondents for baseline level of walking for exercise. Respondents overrepresented Caucasian and middle to high education (or income) adults. Residualized measures of change in walking for exercise served as the dependent variable, adjusted for baseline walking. Similarly, key independent variables, subject to change over time, were included after residualization. At both baseline and 24 months follow-up, adults walked for exercise an average of just under 1 hour per week, and 23.5% of the initially active adults ceased walking for exercise at 2 years. Multiple regression analyses explained more variance in walking for exercise among women than men. Change in dynamic variables such as friend's support and vigorous physical activity accounted for most of the explained variance. Results suggest that dynamic variables may need to be sustained to maintain walking for exercise. The limited explained variance suggests that more precise measures and additional determinants of walking for exercise need to be identified.

Adult↗
PubMed2003

Moderate physical activity permits acute coupling between serum leptin and appetite-satiety measures in obese women.

OBJECTIVES: To investigate whether moderate physical activity or snack intake influence appetite sensations and subsequent food intake in obese women. Associations between serum leptin and appetite ratings were also investigated. METHODS: In all, 10 obese women (mean age+/-s.d.: 50.0+/-8.5 y; mean body mass index (BMI)+/-s.d.: 37.2+/-6.5 kg m(-2)) were submitted in random order to three trials: Moderate physical activity (20 min brisk walking), Snack (58.5 g chocolate-based) and Control (sitting, TV-watching). Appetite and satiety were assessed by visual analogue scales, and serum leptin, blood glucose and plasma free fatty acids were measured at baseline, pre- and postintervention and 1 h postintervention (ie, before dinner). A buffet-style dinner was provided subsequent to the three trials. RESULTS: The moderate physical activity and snack intake both produced lower appetite and higher satiety and fullness perceptions, compared to control, following the intervention. No significant differences were found in subsequent food intake. Serum leptin concentrations did not differ between trials. Serum leptin was not associated with appetite or satiety sensations at any time during the control or the snack trials, but was correlated following moderate physical activity (prospective food consumption r(s)=-0.83, P=0.003; hunger r(s)=-0.79, P=0.007; desire to eat r(s)=-0.69, P=0.02; satiety r(s)=0.71, P=0.02; fullness r(s)=0.66, P=0.04). These associations were not influenced by BMI or fat mass. CONCLUSIONS: Moderate physical activity and snack intake suppress the appetite of obese women acutely. The associations between circulating leptin and appetite-satiety ratings suggest leptin involvement in short-term appetite regulation in response to physical activity-induced factors.

Adult↗