Classifying smartphone-based accelerometer data to obtain validated measures of subject activity status, step count, and gait speed

AbstractBackgroundThe ubiquitous spread of smartphone technology throughout global societies offers an unprecedented opportunity to ethically obtain long-term, highly accurate measurements of individual physical activity. For example, the smartphone intrinsic 3-D accelerometer can be queried during normal phone operation to save time series of acceleration magnitudes (in each of the component directions) for near-real time or post processing.ObjectiveWe describe simple, straightforward algorithms (based on windowed Fourier analysis) for accelerometer data quality control and behavioral classification.MethodsTo maximize the clinical utility of our classifications, we focused on differentiating the following conditions: forgotten phone, subject resting, low physical activity, high physical activity. We further differentiated high physical activity into epochs of walking and climbing stairs, and further quantified walking to infer step count and gait speed.ResultsWe validated these algorithms in 75 individuals, in both laboratory (treadmill) and naturalistic settings. Our algorithm performance was quite satisfactory, with accuracies of 92-99% for all behavioral categories, and 87-90% for gait metrics in naturalistic settings.ConclusionsWe conclude that smartphones are valid and accurate platforms for measuring day-to-day physical activity in ambulatory, community dwelling individuals.

Download Full-text

Novel Analytic Approaches to Investigate Minute-Level Actigraphy and Associations With Physical Function

Innovation in Aging ◽

10.1093/geroni/igaa057.630 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

pp. 194-195

Author(s):

Kaiyuan Hua ◽

Sheng Luo ◽

Katherine Hall ◽

Miriam Morey ◽

Harvey Cohen

Keyword(s):

Physical Activity ◽

Data Analysis ◽

Physical Function ◽

Functional Data Analysis ◽

Functional Data ◽

Gait Speed ◽

Community Dwelling ◽

Accelerometer Data ◽

Single Leg Stance ◽

Minute Walk

Abstract Background. Functional decline in conjunction with low levels of physical activity has implications for health risks in older adults. Previous studies have examined the associations between accelerometry-derived activity and physical function, but most of these studies reduced these data into average means of total daily physical activity (e.g., daily step counts). A new method of analysis “functional data analysis” provides more in-depth capability using minute-level accelerometer data. Methods. A secondary analysis of community-dwelling adults ages 30 to 90+ residing in southwest region of North Carolina from the Physical Performance across the Lifespan (PALS) study. PALS assessments were completed in-person at baseline and one-week of accelerometry. Final analysis includes 669 observations at baseline with minute-level accelerometer data from 7:00 to 23:00, after removing non-wear time. A novel scalar-on-function regression analysis was used to explore the associations between baseline physical activity features (minute-by-minute vector magnitude generated from accelerometer) and baseline physical function (gait speed, single leg stance, chair stands, and 6-minute walk test) with control for baseline age, sex, race and body mass index. Results. The functional regressions were significant for specific times of day indicating increased physical activity associated with increased physical function around 8:00, 9:30 and 15:30-17:00 for rapid gait speed; 9:00-10:30 and 15:00-16:30 for normal gait speed; 9:00-10:30 for single leg stance; 9:30-11:30 and 15:00-18:00 for chair stands; 9:00-11:30 and 15:00-18:30 for 6-minute walk. Conclusion. This method of functional data analysis provides news insights into the relationship between minute-by-minute daily activity and health.

Download Full-text

A Semi-Quantitative Method to Denote Generic Physical Activity Phenotypes from Long-Term Accelerometer Data – The ATLAS Index

PLoS ONE ◽

10.1371/journal.pone.0063522 ◽

2013 ◽

Vol 8 (5) ◽

pp. e63522 ◽

Cited By ~ 13

Author(s):

Michael Marschollek

Keyword(s):

Physical Activity ◽

Quantitative Method ◽

Accelerometer Data

Download Full-text

Strength, Static Balance, Physical Activity, and Age Predict Maximal Gait Speed in Healthy Older Adults From a Rural Community: A Cross-Sectional Study

Journal of Aging and Physical Activity ◽

10.1123/japa.2014-0081 ◽

2015 ◽

Vol 23 (4) ◽

pp. 580-587 ◽

Cited By ~ 3

Author(s):

Silvia Aranda-García ◽

Albert Busquets ◽

Antoni Planas ◽

Joan A. Prat-Subirana ◽

Rosa M. Angulo-Barroso

Keyword(s):

Physical Activity ◽

Older Adults ◽

Rural Community ◽

Gait Speed ◽

Cross Sectional Study ◽

Community Dwelling ◽

Knee Extensors ◽

Sectional Study ◽

Cross Sectional ◽

Physical Abilities

Purpose:Gait speed is related to physical function in older adults. This cross-sectional study examined the best predictors of maximal gait speed (MGS) among physical abilities, and general factors in healthy, rural community-dwelling older adults.Methods:MGS, muscle strength, and postural sway were measured in 55 community-dwelling participants (age, 72.1 ± 6.8, range 61–87 years; 72.7% women). Two stepwise regressions were used to find MGS predictors in two models: physical abilities and global.Results:Strength of knee extensors with 60° of knee flexion (KStrength60°) and maximal distance in the anterior-posterior direction with eyes closed explained 50.2% of MGS variance (p < .05) in the physical abilities model. KStrength60°, age, and level of physical activity explained 63.9% of MGS variance (p < .05) in the global model.Conclusions:Regardless of the model, KStrength60° was the best predictor of MGS in rural female older adults. Future research should examine the generalization of these findings to rural male older adults.

Download Full-text

Exercise on Prescription: A Cross-sectional Study With Self-reported Outcome

Journal of Physical Activity and Health ◽

10.1123/jpah.2015-0015 ◽

2016 ◽

Vol 13 (4) ◽

pp. 377-384 ◽

Cited By ~ 1

Author(s):

Helene Buch Pedersen ◽

Morten Helmer-Nielsen ◽

Karin Brochstedt Dieperink ◽

Birte Østergaard

Keyword(s):

Physical Activity ◽

Chronic Diseases ◽

Leisure Time ◽

Cross Sectional Study ◽

Community Dwelling ◽

Cross Sectional Survey ◽

Cross Sectional ◽

Physically Active ◽

Lifestyle Diseases

Background:Exercise on prescription (EOP) is an attempt to increase physical activity among sedentary adults with signs of lifestyle diseases. Until now, no studies have focused on patients with chronic diseases and how they assess the long-term effect of participating in EOP consisting of supervised interventions of different intensities. This study aimed to describe and compare self-reported physical activity in the long term among participants in 3 EOP modules of different intensities.Methods:A cross-sectional survey was conducted among 1152 former participants in EOP between July 2005 and May 2007 in 2 Danish counties. Physical activity was measured as number of days with a minimum 30 minutes of moderate/vigorous activity.Results:Seventy-five percent (n = 854) returned the questionnaire. Of these, 36% reported being physically active ≥ 5 days/week. Comparing leisure-time activities before EOP 29% was sedentary vs. 15% (P < 0 .01) after, moderate + hard leisure-time activities was 7% before vs. 19% after EOP (P < 0 .01). Time postintervention did not influence the numbers reporting to be physical active negatively.Conclusions:This study in community-dwelling adults with chronic diseases participating in EOP finds that approximately one-third reported being physically active in the long term postintervention, but no differences between the modalities were found.

Download Full-text

The Prediction of ADL and IADL Disability Using Six Physical Indicators of Frailty: A Longitudinal Study in the Netherlands

Current Gerontology and Geriatrics Research ◽

10.1155/2014/358137 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 33

Author(s):

Robbert J. J. Gobbens ◽

Marcel A. L. M. van Assen

Keyword(s):

Physical Activity ◽

Grip Strength ◽

Gait Speed ◽

Response Rate ◽

Hand Grip Strength ◽

Community Dwelling ◽

Physical Frailty ◽

Activity Restriction ◽

Hand Grip ◽

Iadl Disability

Frailty is a predictor of disability. A proper understanding of the contribution of individual indicators of frailty in the prediction of disability is a requisite for preventive interventions. The aim of this study was to determine the predictive power of the individual physical frailty indicators: gait speed, physical activity, hand grip strength, Body Mass Index (BMI), fatigue, and balance, for ADL and IADL disability. The sample consisted of 505 community-dwelling persons (≥75 years, response rate 35.1%). Respondents first participated between November 2007 and June 2008, and a subset of all respondents participated again one year later (N=264, 52.3% response rate). ADL and IADL disability were assessed by the Groningen Activity Restriction Scale. BMI was assessed by self-report, and the other physical frailty indicators were assessed with the TUG test (gait speed), the LAPAQ (physical activity), a hand grip strength test, the SFQ (fatigue), and the Four-test balance scale. All six physical frailty indicators were associated with ADL and IADL disability. After controlling for previous disability, sociodemographic characteristics, self-perceived lifestyle, and chronic diseases, only gait speed was predictive of both ADL and IADL disability, whereas there was a small effect of fatigue on IADL disability. Hence, these physical frailty indicators should be included in frailty assessment when predicting future disability.

Download Full-text

Instrumented Assessment of Physical Activity Is Associated With Muscle Function but Not With Muscle Mass in a General Population

Journal of Aging and Health ◽

10.1177/0898264317721554 ◽

2017 ◽

Vol 30 (9) ◽

pp. 1462-1481 ◽

Cited By ~ 8

Author(s):

Anna G. M. Rojer ◽

Esmee M. Reijnierse ◽

Marijke C. Trappenburg ◽

Rob C. van Lummel ◽

Martijn Niessen ◽

...

Keyword(s):

Physical Activity ◽

General Population ◽

Muscle Mass ◽

Gait Speed ◽

Muscle Function ◽

Handgrip Strength ◽

Group Discussion ◽

Community Dwelling ◽

Self Report ◽

Middle Aged

Objectives: Self-reported physical activity has shown to affect muscle-related parameters. As self-report is likely biased, this study aimed to assess the association between instrumented assessment of physical activity (I-PA) and muscle-related parameters in a general population. Method: Included were 156 young-to-middle-aged and 80 older community-dwelling adults. Seven days of trunk accelerometry (DynaPort MoveMonitor, McRoberts B.V.) quantified daily physical activity (i.e., active/inactive duration, number and mean duration of active/inactive periods, and number of steps per day). Muscle-related parameters included muscle mass, handgrip strength, and gait speed. Results: I-PA was associated with handgrip strength in young-to-middle-aged adults and with gait speed in older adults. I-PA was not associated with muscle mass in either age group. Discussion: The association between I-PA and muscle-related parameters was age dependent. The lack of an association between I-PA and muscle mass indicates the relevance of muscle function rather than muscle mass.

Download Full-text

Associations of frailty, physical activity, and physical fitness with incident long-term care and support needs in community-dwelling older Japanese adults

Japanese Journal of Physical Fitness and Sports Medicine ◽

10.7600/jspfsm.68.303 ◽

2019 ◽

Vol 68 (5) ◽

pp. 303-312

Author(s):

Kenji Narazaki ◽

Shuzo Kumagai

Keyword(s):

Physical Activity ◽

Physical Fitness ◽

Long Term Care ◽

Community Dwelling ◽

Support Needs ◽

Term Care ◽

Care And Support ◽

Japanese Adults

Download Full-text

Long-term high physical activity modulates event-related potential indices of inhibitory control in postmenopausal women

PeerJ ◽

10.7717/peerj.6523 ◽

2019 ◽

Vol 7 ◽

pp. e6523

Author(s):

Chang Xu ◽

Yingzhi Lu ◽

Biye Wang ◽

Chenglin Zhou

Keyword(s):

Physical Activity ◽

Alzheimer Disease ◽

Postmenopausal Women ◽

Inhibitory Control ◽

High Intensity ◽

Control Group ◽

High Physical Activity ◽

Activity Group ◽

Physical Activity Group

Background Inhibition processing is sensitive to aging, and an age-related decline in inhibition processing has been associated with an accelerated rate of progression to Alzheimer disease. Elderly women are two to three times more likely than age-matched men to have Alzheimer disease. Therefore, this study examined whether long-term high physical activity affects inhibitory processing, specifically among postmenopausal women. Methods In total, 251 candidates were screened using the Montreal Cognitive Assessment and the Raven’s Standard Progressive Matrices to assess their cognitive abilities and the International Physical Activity Questionnaire (Chinese version) to assess their physical activity levels. The participants were then grouped into either a long-term high physical activity group (defined as more than 3 days of high intensity activity per week and gross metabolic equivalent minutes (MET-minutes) higher than 1,500 MET-minutes/week or a gross MET higher than 3,000 MET-minutes/week obtained through walking or other moderate or high intensity activity) or a control group and matched for demographic and health characteristics as well as cognitive scores. Event-related potentials (ERPs) were recorded as participants performed a Go/No-go task to assess inhibition processing. Results The long-term high physical activity group (n = 30) had faster Go reaction times than the control group (n = 30), whereas no significant difference between the two groups was found in their performance accuracy on the No-go task. For the ERP results, the latency of N2 component was significantly shorter in the long-term high physical activity group than that in the control group. Discussion The results of this study suggested that long-term high physical activity may increase the efficiency of the inhibitory control system by increasing the activity of response monitoring processes.

Download Full-text

Association Between Brain Volumes and Patterns of Physical Activity in Community-Dwelling Older Adults

The Journals of Gerontology Series A ◽

10.1093/gerona/glaa294 ◽

2020 ◽

Author(s):

Amal A Wanigatunga ◽

Hang Wang ◽

Yang An ◽

Eleanor M Simonsick ◽

Qu Tian ◽

...

Keyword(s):

Physical Activity ◽

Older Adults ◽

White Matter ◽

Brain Structure ◽

Community Dwelling ◽

Sensitivity Analyses ◽

Intracranial Volume ◽

Accelerometer Data ◽

Brain Volumes ◽

Cognitively Normal

Abstract Background Larger brain volumes are often associated with more free-living physical activity (PA) in cognitively normal older adults. Yet, whether greater brain volumes are associated with more favorable (less fragmented) PA patterns, and whether this association is stronger than with total PA, remains unknown. Methods Brain magnetic resonance imaging and wrist-worn accelerometer data were collected in 301 participants (mean age = 77 [SD = 7] years, 59% women) enrolled in the Baltimore Longitudinal Study of Aging. Linear regression models were fit to examine whether brain volumes (cc) were cross-sectionally associated with: (a) total daily PA minutes and (b) activity fragmentation (mean number of PA bouts / total PA minutes × 100). Sensitivity analyses were conducted by adjusting for counterpart PA variables (eg, fragmentation covariate included in the PA minutes model). Results Greater white matter volumes in the parietal and temporal lobes were associated with higher daily PA minutes (2.6 [SE = 1.0] and 3.8 [0.9] min/day, respectively; p < .009 for both) after adjusting for demographics, behavioral factors, medical conditions, gait speed, apolipoprotein E e4 status, and intracranial volume. Greater temporal white matter volume was associated with lower fragmentation (−0.16% [0.05], p = .003). In sensitivity analyses, observed associations between brain volumes and daily PA minutes remained significant while associations with fragmentation no longer remained significant. Conclusions Our results suggest white matter brain structure in cognitively normal older adults is associated with the total amount of PA and, to a lesser extent, the PA accumulation patterns. More work is needed to elucidate the longitudinal relationship between brain structure and function and PA patterns with aging.

Download Full-text