Evaluation of Low‐Intensity Physical Activity by Triaxial Accelerometry

Abstract

Research Methods and Procedures:Twenty-one Japanese adults were fitted with a triaxial accelerometer while also in a whole-body human calorimeter for 22.5 hours. The protocol time was composed of sleep (8 hours), four structured activity periods totaling 4 hours (sitting, standing, housework, and walking on a treadmill at speeds of 71 and 95 m/min, 2 ϫ 30 minutes for each activity), and residual time (10.5 hours). Acceleration data (milligausse) from the different periods and their relationship to physical activity ratio obtained from the human calorimeter allowed for the development of EE equations for each activity. The EE equations were validated on the residual times, and the percentage difference for the prediction errors was calculated as (predicted value Ϫ measured value)/measured value ϫ 100. Results: Using data from triaxial accelerations and the ratio of horizontal to vertical accelerations, there was relatively high accuracy in identifying the four different periods of activity. The predicted EE (882 Ϯ 150 kcal/10.5 hours) was strongly correlated with the actual EE measured by human calorimetry (846 Ϯ 146 kcal/10.5 hours, r ϭ 0.94 p Ͻ 0.01), although the predicted EE was slightly higher than the measured EE. Discussion: Triaxial accelerometry, when total, vertical, and horizontal accelerations are utilized, can effectively evaluate different types of activities and estimate EE for low-intensity physical activities associated with modern lifestyles.

Longer Time Spent in Light Physical Activity Is Associated With Reduced Arterial Stiffness in Older Adults

“…Therefore, we determined the relationships between the daily times spent in inactivity and light, moderate, and vigorous PA and arterial stiffness. The strength of the present study was that daily PA levels of subjects were evaluated by triaxial accelerometry, because self-reported PA may be subject to bias and misclassification, 10 and this method allows for better determination of light PA. 16 Similar to previous findings, the present study also showed that arterial stiffness was significantly related to the daily time spent in moderate PA in middle-aged and older groups. More importantly, the present study first demonstrated that the daily time spent in light PA was inversely related with arterial stiffness in the older group, independent of the daily time spent in moderate and vigorous PA.…”

“…15,16 Objective evidence has been reported indicating that light PA has a relatively high energy cost during daily living 13,17 and is beneficially associated with traditional risk factors. 18 Therefore, we hypothesized that the longer time spent in light PA assessed by triaxial accelerometry may be associated with reduced arterial stiffening.…”

Assessment of physical activity: a critical appraisal

“…Ainsworth et al (2000) categorized dynamic activities such as walking and cycling into light, moderate or vigorous intensity depending on movement speed for the estimation of energy expenditure. There is a linear relationship between accelerometer and energy expenditure, however, this linearity is valid only within one single activity type (Hendelman et al 2000;Midorikawa et al 2007). Trunk mounted accelerometer systems can be used to assess speed of movement (Schutz et al 2002).…”

Preliminary study for the assessment of physical activity using a triaxial accelerometer with a gyro sensor on the upper limbs of subjects with paraplegia driving a wheelchair on a treadmill

“…Therefore, the development and validation of wearable monitors such as pedometers, load transducers/foot-contact monitors, accelerometers, heart rate monitors, combined accelerometer and heart rate monitors and multiple sensor systems that enable the evaluation of physical activity in healthy individuals are in progress. 4 In Japan, Tanaka et al [5][6][7] investigated the relationships between each axes in a wearable lumbar triaxial accelerometer and EE in abled-bodied person, linear/non-linear relationship, adoption of a synthesized value and development of a gravity-removal classification algorithm; this has led to commercialization of the latter. The validation of such diverse products contributes enormously to the research and development of practical activities for promoting the health of all people from children to the elderly.…”