Self-reported injury and physical activity levels: United States 2000 to 2002.

PURPOSE: The aim of the study is to compare national estimates of the incidence of self-reported all-cause and activity-specific injuries in adults with differing leisure-time physical activity levels. METHODS: Data were analyzed from the 2000 to 2002 National Health Interview Survey. Leisure-time physical activity levels were categorized as active, insufficiently active, and inactive. RESULTS: Age-adjusted incidences of all-cause injury did not differ by leisure-time physical activity level (active, 89.3/1000; 95% confidence interval [CI], 81.8-96.8; insufficiently active, 81.6/1000; 95% CI, 73.1-90.1; and inactive, 86.3/1000; 95% CI, 78.6-93.9). Active respondents (29.4/1000; 95% CI, 25.2-33.6) had a greater incidence of injury related to sport and leisure-time activities than inactive respondents (15.2/1000; 95% CI, 12.1-18.3), whereas inactive respondents (71.1/1000; 95% CI, 63.9-78.2) had a greater incidence of injury related to nonsport and non-leisure-time activities than active respondents (59.9/1000; 95% CI, 53.6-66.2). Results were unchanged after multivariate control for confounding factors. CONCLUSIONS: Although the incidence of sport and leisure-time injuries is associated with participation in leisure-time physical activity, no association was observed between leisure-time physical activity and overall injuries.

Prevalence of physical activity in the United States: Behavioral Risk Factor Surveillance System, 2001.

INTRODUCTION: The health benefits of regular cardiovascular exercise are well-known. Such exercise, however, has traditionally been defined as vigorous physical activity, such as jogging, swimming, or aerobic dance. Exercise of moderate intensity also promotes health, and many U.S. adults may be experiencing the health benefits of exercise through lifestyle activities of moderate intensity, such as yard work, housework, or walking for transportation. Until recently, public health surveillance systems have not included assessments of this type of physical activity, focusing on exercise of vigorous intensity. We used an enhanced surveillance tool to describe the prevalence and amount of both moderate-intensity and vigorous-intensity physical activity among U.S. adults. METHODS: We analyzed data from the 2001 Behavioral Risk Factor Surveillance System, a state-based, random-digit-dialed telephone survey administered to U.S. adults aged 18 years and older (n = 82,834 men and 120,286 women). Physical activity behavior was assessed using questions designed to quantify the frequency of participation in moderate- or vigorous-intensity physical activities performed during leisure time or for household chores and transportation. RESULTS: Overall, 45% of adults (48% of men and 43% of women) were active at recommended levels during nonworking hours (at least 30 minutes five or more days per week in moderate-intensity activities, equivalent to brisk walking, or at least 20 minutes three or more days per week in vigorous activities, equivalent to running, heavy yard work, or aerobic dance). Less than 16% of adults (15% of men and 17% of women) reported no moderate or vigorous activity in a usual week. CONCLUSION: Integrating surveillance of lifestyle activities into national systems is possible, and doing so may provide a more accurate representation of the prevalence of recommended levels of physical activity. These results, however, suggest that the majority of U.S. adults are not active at levels associated with the promotion and maintenance of health.

Descriptive epidemiology of pedometer-determined physical activity.

PURPOSE: The dual purposes of this study were: 1) to provide preliminary descriptive epidemiology data representing pedometer-determined physical activity (PA) and 2) to explore sources of intra-individual variability in steps per day. METHODS: All participants (76 males, age = 48.4 +/- 16.3 yr, body mass index (BMI) = 27.1 +/- 5.1 kg x m(-2); 133 females, age = 47.4 +/- 17.5 yr, BMI = 26.9 +/- 5.7 kg x m(-2)) resided in Sumter County, SC, and were recruited by telephone to receive a mailed kit to self-monitor PA for 1 wk. Statistical analyses compared mean steps per day between sexes, races, age groups, education and income levels, and BMI categories. Mean steps per day were also compared between: 1) weekdays versus weekend days, 2) workdays versus nonworkdays, and 3) days of sport/exercise versus no participation. RESULTS: The entire sample took 5931 +/- 3664 steps x d(-1) (males = 7192 +/- 3596 vs females = 5210 +/- 3518 steps x d(-1), t = 7.88, P < 0.0001). Significant differences were also indicated by race, age, education, income, and BMI. In addition, weekdays were significantly higher than weekend days, workdays were higher than nonworkdays, and sport/exercise days were higher than nonsport/exercise days. CONCLUSIONS: The large standard deviations reflect a wide distribution of ambulatory behavior. Regardless, important differences are still evident by demographic characteristics, BMI categories, day of the week, and reported engagement in work or sport/exercise.

The impact of stretching on sports injury risk: a systematic review of the literature.

PURPOSE: We conducted a systematic review to assess the evidence for the effectiveness of stretching as a tool to prevent injuries in sports and to make recommendations for research and prevention. METHODS: Without language limitations, we searched electronic data bases, including MEDLINE (1966-2002), Current Contents (1997-2002), Biomedical Collection (1993-1999), the Cochrane Library, and SPORTDiscus, and then identified citations from papers retrieved and contacted experts in the field. Meta-analysis was limited to randomized trials or cohort studies for interventions that included stretching. Studies were excluded that lacked controls, in which stretching could not be assessed independently, or where studies did not include subjects in sporting or fitness activities. All articles were screened initially by one author. Six of 361 identified articles compared stretching with other methods to prevent injury. Data were abstracted by one author and then reviewed independently by three others. Data quality was assessed independently by three authors using a previously standardized instrument, and reviewers met to reconcile substantive differences in interpretation. We calculated weighted pooled odds ratios based on an intention-to-treat analysis as well as subgroup analyses by quality score and study design. RESULTS: Stretching was not significantly associated with a reduction in total injuries (OR = 0.93, CI 0.78-1.11) and similar findings were seen in the subgroup analyses. CONCLUSION: There is not sufficient evidence to endorse or discontinue routine stretching before or after exercise to prevent injury among competitive or recreational athletes. Further research, especially well-conducted randomized controlled trials, is urgently needed to determine the proper role of stretching in sports.

Environmental measures of physical activity supports: perception versus reality.

BACKGROUND: Perceptions of the environment and physical activity have been associated using survey methods, yet little is known about the validity of environmental surveys. In this study, perceptions of the environment at neighborhood and community levels were assessed (1) to determine validity by comparing respondent perceptions to objective measures and (2) to determine test-retest reliability of the survey. METHODS: A telephone survey was administered to a stratified sample of Sumter County, South Carolina adults. Respondents' home addresses were mapped using a geographic information system (GIS) (n =1112). As an indicator of validity, kappa statistics were used to measure agreement between perceptions and objective measures identified at neighborhood and community levels using GIS. A second survey in an independent sample (n=408) assessed test-retest reliability. RESULTS: When assessing perceptions of environmental and physical activity in a defined geographic area, validity and reliability for neighborhood survey items were kappa= -0.02 to 0.37 and rho=0.42 to 0.74, and for community survey items were kappa= -0.07 to 0.25 and rho=0.28 to 0.56. CONCLUSIONS: Although causality between perception of access and safety and actual physical activity level cannot be assumed, those meeting national physical activity guidelines or reporting some physical activity demonstrated greatest agreement with access to recreation facilities, while those not meeting the guidelines demonstrated greater agreement with safety of recreation facilities. Factors such as distance and behavior may explain differences in perceptions at neighborhood and community levels. Using local environments with short distances in survey methods improves validity and reliability of results.

The prevention of shin splints in sports: a systematic review of literature.

PURPOSE: To review the published and unpublished evidence regarding risk factors associated with shin splints, assess the effectiveness of prevention strategies, and offer evidence-based recommendations to coaches, athletes, and researchers. METHODS: We searched electronic data bases without language restriction, identified citations from reference sections of research papers retrieved, contacted experts in the field, and searched the Cochrane Collaboration. Of the 199 citations identified, we emphasized results of the four reports that compared methods to prevent shin splints. We assessed the methodologic quality of these reports by using a standardized instrument. RESULTS: The use of shock-absorbent insoles, foam heel pads, heel cord stretching, alternative footwear, as well as graduated running programs among military recruits have undergone assessment in controlled trials. There is no strong support for any of these interventions, and each of the four controlled trials is limited methodologically. Median quality scores in these four studies ranged from 29 to 47, and serious flaws in study design, control of bias, and statistical methods were identified. CONCLUSION: Our review yielded little objective evidence to support widespread use of any existing interventions to prevent shin splints. The most encouraging evidence for effective prevention of shin splints involves the use of shock-absorbing insoles. However, serious flaws in study design and implementation constrain the work in this field thus far. A rigorously implemented research program is critically needed to address this common sports medicine problem.