Background: Accelerometers provide an objective assessment of physical activity and are frequently deployed for at least multiple days. However, it is unclear how to summarize multiple days into one overall physical activity estimate, particularly in the presence of missing data. This study compared summarization method prediction and precision, and the ...
Hip bone mineral density (BMD) is an important biomarker of fracture risk, but as a standalone measure it lacks information on modifiable causal factors. The relationship between hip BMD and physical activity (PA)-based skeletal loading estimates could provide a biomarker for prescribing PA changes in high risk patients. Ten ...
We will present the results of analysis of physical activity data collected with accelerometers on 10000+ subjects in National Health and Nutrition Examination Survey (NHANES), a nationally representative sample of the US population. The data have been analyzed with recently developed multilevel functional data analysis approaches that focus on modeling variability ...
Introduction Recent physical activity (PA) guidelines incorporate recognition of the greater health benefits from higher intensity PA, but still dichotomize intensity into moderate or vigorous categories. New ubiquitous wearable accelerometry enables the estimation of intensity along the continuum from moderate intensity upwards. Purpose To compare two versions of a MET-min ...
Purpose To contrast the associations of objectively measured moderate-to-vigorous physical activity (MVPA) and total accelerometer counts with biomarkers in a representative sample of U.S. adults. Methods Data from the 2003 - 2006 NHANES were used for this analysis. The sample included adults ≥ 20 y, not pregnant or lactating, who had self-reported PA ...
Introduction In classifying actigraphy signals, features are usually extracted from raw data and then fed to some sort of a classifier that determines the type and level of activity. A huge variety of features have been tried by many researchers in this field. Some features are statistical in nature, some ...
Introduction Tri-axial accelerometers record the acceleration of people’s daily activity on three orthogonal directions. One fundamental question is how to decipher and interpret the acceleration signals into meaningful information such as types of human movement. Purpose We provide statistical methods for predicting activity type and answer the following questions: 1) ...
Introduction The field of physical activity monitoring has developed rapidly over the last decade. It is becoming more common to apply accelerometer-based physical activity monitors in large population based samples. The researchers are faced with large variety of choices regarding settings including wear and non-wear criteria. As no consensus has ...
Purpose Understanding fluctuations in lifestyle indicators is important to identify relevant time periods to intervene in order to promote a healthy lifestyle; however, objective assessment of multiple lifestyle indicators has never been done using a repeated-measures design. The primary aim was, therefore, to examine between-season and within-week variation in physical ...
Introduction Given its associations with morbidity and mortality, sedentary behaviour (SB) has emerged as a potentially significant public health issue. Although most studies of relationships between SB and health outcomes acknowledge that some sort of adjustment should be made for physical activity, there is no consensus on the approach for ...