Monitoring Community Mobility With Global Positioning System Technology After a Stroke: A Case Study

Fusing GPS, Activity Monitors, and Self-Report to Improve Assessment of Walking Activity and Community Participation After Stroke

BACKGROUND AND PURPOSE

Walking and participation in the community are important goals for people post-stroke (PPS). These constructs are challenging to measure given limitations in current data collection methodologies. The purpose of this study was to (1) develop a data fusion approach that combined data from global positioning system (GPS), activity monitor (AM), and daily trip log to identify walking activity and participation in the community, and (2) to examine the construct validity of the data fusion method.

METHODS

At 60 days post-stroke, PPS wore a GPS and AM and completed a daily trip log for 7 days. Using a combination of a density-based spatial clustering algorithm and geocoding GPS, AM, and daily trip log data were time synched and fused to identify total trips taken outside the home; locations visited per trip; number of steps taken in the home, in the community, at each location visited, and in total. Associations between stroke outcomes and the data fusion metrics were determined to support the construct validity of the data fusion method.

RESULTS

Forty-four PPS took a mean of 2,541 steps/day, of which 56% were in the community, and took a mean of 0.39 trips/day outside the home and visited a mean of 0.42 locations. A social visit was the most common reason for going into the community. There were fair associations between number of trips outside the home and gait speed (GS), r = 0.49, Berg Balance Scale (BBS), r = 0.48, modified Rankin Scale (mRS), r = -0.47, and Stroke Impact Scale participation subscale (SIS-P) (0.45). There were moderate associations between steps taken in the community and GS, r = 0.63, BBS, r = 0.51, mRS, r = -0.61, and SIS-P, r = 0.43.

DISCUSSION AND CONCLUSIONS

Participants did not often access their community. Fusing GPS, AM, and trip log data may provide a comprehensive method to identify walking activity and community participation in PPS.

VIDEO ABSTRACT AVAILABLE

for more insights from the authors (see the Video, Supplemental Digital Content, available at: http://links.lww.com/JNPT/A529).

Sensor-Based Gait and Balance Assessment in Healthy Adults: Analysis of Short-Term Training and Sensor Placement Effects

While the analysis of gait and balance can be an important indicator of age- or disease-related changes, it remains unclear if repeated performance of gait and balance tests in healthy adults leads to habituation effects, if short-term gait and balance training can improve gait and balance performance, and whether the placement of wearable sensors influences the measurement accuracy. Healthy adults were assessed before and after performing weekly gait and balance tests over three weeks by using a force plate, motion capturing system and smartphone. The intervention group (n = 25) additionally received a home-based gait and balance training plan. Another sample of healthy adults (n = 32) was assessed once to analyze the impact of sensor placement (lower back vs. lower abdomen) on gait and balance analysis. Both the control and intervention group exhibited improvements in gait/stance. However, the trends over time were similar for both groups, suggesting that targeted training and repeated task performance equally contributed to the improvement of the measured variables. Since no significant differences were found in sensor placement, we suggest that a smartphone used as a wearable sensor could be worn both on the lower abdomen and the lower back in gait and balance analyses.

Effectiveness of pedometer-based walking programmes in improving some modifiable risk factors of stroke among community-dwelling older adults: a systematic review, theoretical synthesis and meta-analysis

BACKGROUND

Pedometer-based walking programs hold promise as a health promotion strategy for stroke prevention in community-dwelling older adults, particularly when targeted at physical activity-related modifiable risk factors. The question arises: What is the effectiveness of pedometer-based walking program interventions in improving modifiable stroke risk factors among community-dwelling older adults?

METHOD

Eight databases were searched up to December 2nd, 2023, following the Preferred Reporting Items for Systematic Review and Meta-Analysis protocol. Inclusion criteria focused on randomized controlled trials (RCTS) involving community-dwelling older adults and reported in English. Two independent reviewers utilized Physiotherapy Evidence Database (PEDro) tool to extract data, assess eligibility, evaluate study quality, and identify potential bias. Standardized mean difference (SMD) was employed as summary statistics for primary -physical activity level -and secondary outcomes related to cardiovascular function (blood pressure) and metabolic syndrome, including obesity (measured by body mass index and waist circumference), fasting blood sugar, glycated hemoglobin, high-density lipoprotein cholesterol (HDL-C), and triglycerides. A random-effects model was used to generate summary estimates of effects.

RESULTS

The review analyzed eight studies involving 1546 participants aged 60-85 years, with 1348 successfully completing the studies. Across these studies, pedometer-based walking programs were implemented 2-3 times per week, with sessions lasting 40-60 minutes, over a duration of 4-26 weeks. The risk of bias varied from high to moderate. Our narrative synthesis revealed positive trends in HDL-C levels, fasting blood sugar, and glycated hemoglobin, suggesting improved glycemic control and long-term blood sugar management. However, the impact on triglycerides was only marginal. Primary meta-analysis demonstrated significantly improved physical activity behavior (SMD=0.44,95%CI:0.26, 0.61,p=<0.00001;I2=0%;4 studies; 532 participants) and systolic blood pressure (SMD=-0.34,95%CI:-0.59,-0.09;p=<0.008;I2=65%,2 studies;249 participants), unlike diastolic blood pressure (SMD=0.13,95%CI:-0.13,-0.38,p=0.33; I2=91%; 2 studies; 237 participants). Interventions based on social cognitive, self-efficacy, and self-efficiency theory(ies), and social cognitive theory applied in an ecological framework, were linked to successful physical activity behavior outcomes.

CONCLUSION

Pedometer-based walking programs, utilizing interpersonal health behavior theory/ecological framework, enhance physical activity behavior and have antihypertensive effects in community-dwelling older adults. While they do not significantly affect diastolic blood pressure, these programs potentially serve as a primary stroke prevention strategy aligning with global health goals.

TRIAL REGISTRATION

Registration Number: INPLASY202230118.

Systematic review of best practices for GPS data usage, processing, and linkage in health, exposure science and environmental context research

Global Positioning System (GPS) technology is increasingly used in health research to capture individual mobility and contextual and environmental exposures. However, the tools, techniques and decisions for using GPS data vary from study to study, making comparisons and reproducibility challenging.

OBJECTIVES

The objectives of this systematic review were to (1) identify best practices for GPS data collection and processing; (2) quantify reporting of best practices in published studies; and (3) discuss examples found in reviewed manuscripts that future researchers may employ for reporting GPS data usage, processing and linkage of GPS data in health studies.

DESIGN

A systematic review.

DATA SOURCES

Electronic databases searched (24 October 2023) were PubMed, Scopus and Web of Science (PROSPERO ID: CRD42022322166).

ELIGIBILITY CRITERIA

Included peer-reviewed studies published in English met at least one of the criteria: (1) protocols involving GPS for exposure/context and human health research purposes and containing empirical data; (2) linkage of GPS data to other data intended for research on contextual influences on health; (3) associations between GPS-measured mobility or exposures and health; (4) derived variable methods using GPS data in health research; or (5) comparison of GPS tracking with other methods (eg, travel diary).

DATA EXTRACTION AND SYNTHESIS

We examined 157 manuscripts for reporting of best practices including wear time, sampling frequency, data validity, noise/signal loss and data linkage to assess risk of bias.

RESULTS

We found that 6% of the studies did not disclose the GPS device model used, only 12.1% reported the per cent of GPS data lost by signal loss, only 15.7% reported the per cent of GPS data considered to be noise and only 68.2% reported the inclusion criteria for their data.

CONCLUSIONS

Our recommendations for reporting on GPS usage, processing and linkage may be transferrable to other geospatial devices, with the hope of promoting transparency and reproducibility in this research.

PROSPERO REGISTRATION NUMBER

CRD42022322166.

Geographic intelligence to investigate community participation: a scoping review

PURPOSE

To understand the applicability and unique contributions of global positioning system (GPS) and geographic information system (GIS) technologies to investigate individuals' participation in the community.

METHODS

A scoping review was conducted to summarize studies that employed GPS and/or GIS to assess community participation. Systematic literature searches were performed using nine electronic databases, up to April 2022. Two independent reviewers screened studies for eligibility and extracted data from the selected studies.

RESULTS

The searches retrieved 628 articles, of which 36 met the inclusion criteria. In 31 studies, a GPS unit or GPS-enabled device monitored the community mobility of individuals with different health conditions. Tracking periods varied from five hours to 30 consecutive days. The spatiotemporal parameters obtained from satellite-based data provided information about individuals' presence in the community. Most studies combined GPS with other measuring tools (self-report diaries/questionnaires, qualitative interviews) to capture a broader description of community participation.

CONCLUSIONS

GPS and GIS are viable approaches for advancing research as they provide unique information about community participation not easily captured by other methods. The combination of available methods comprehensively address the physical and social dimensions of this construct.IMPLICATIONS FOR REHABILITATIONGlobal positioning system (GPS) and geographic information system (GIS) technology allows direct and real-time quantification of patterns of individuals' community mobility.The geographic area where individuals participate in daily living activities complements information from self-report diaries/questionnaires.Combining GPS technology with self-report diaries/questionnaires allows a broader description of individuals' community participation, addressing respectively both its physical and social dimensions.Knowledge of individuals' access to and involvement in community locations/situations may help therapists design interventions to improve community participation.

A scoping review on recent trends in wearable sensors to analyze gait in people with stroke: From sensor placement to validation against gold-standard equipment

The purpose of the review is to evaluate wearable sensor placement, their impact and validation of wearable sensors on analyzing gait, primarily the postural instability in people with stroke. Databases, namely PubMed, Cochrane, SpringerLink, and IEEE Xplore were searched to identify related articles published since January 2005. The authors have selected the articles by considering patient characteristics, intervention details, and outcome measurements by following the priorly set inclusion and exclusion criteria. From a total of 1077 articles, 142 were included in this study and classified into functional fields, namely postural stability (PS) assessments, physical activity monitoring (PA), gait pattern classification (GPC), and foot drop correction (FDC). The review covers the types of wearable sensors, their placement, and their performance in terms of reliability and validity. When employing a single wearable sensor, the pelvis and foot were the most used locations for detecting gait asymmetry and kinetic parameters, respectively. Multiple Inertial Measurement Units placed at different body parts were effectively used to estimate postural stability and gait pattern. This review article has compared results of placement of sensors at different locations helping researchers and clinicians to identify the best possible placement for sensors to measure specific kinematic and kinetic parameters in persons with stroke.

Comparison of GPS imputation methods in environmental health research

Assessment of personal exposure in the external environment commonly relies on global positioning system (GPS) measurements. However, it has been challenging to determine exposures accurately due to missing data in GPS trajectories. In environmental health research using GPS, missing data are often discarded or are typically imputed based on the last known location or linear interpolation. Imputation is said to mitigate bias in exposure measures, but methods used are hardly evaluated against ground truth. Widely used imputation methods assume that a person is either stationary or constantly moving during the missing interval. Relaxing this assumption, we propose a method for imputing locations as a function of a person's likely movement state (stop, move) during the missing interval. We then evaluate the proposed method in terms of the accuracy of imputed location, movement state, and daily mobility measures such as the number of trips and time spent on places visited. Experiments based on real data collected by participants (n=59) show that the proposed approach outperforms existing methods. Imputation to the last known location can lead to large deviation from the actual location when gap distance is large. Linear interpolation is shown to result in large errors in mobility measures. Researchers should be aware that the different treatment of missing data can affect the spatiotemporal accuracy of GPS-based exposure assessments.

Location monitoring of physical activity and participation in community dwelling older people: a scoping review

Background: Community participation and physical activity are important for the health of older adults. This review aimed to identify studies which have measured physical activity and community participation in older adults using Global positioning systems.Materials and methods: This scoping review searched key databases using predetermined subject headings and keywords. Two independent reviewers selected studies based on a systematic procedure following current guidelines. Inclusion criteria for studies were: participants aged over 50 years living independently in the community that reported on physical activity and/or participation inclusive of physical and social activity, and including a quantitative measure of location. All searches were limited to English. The primary review question was; "What studies have monitored the location of physical activity in an older population?" with secondary enquiries investigating the types of global positioning system devices, barriers and facilitators for activity and community participation.Results: The search returned 3723 articles (following duplicate removal) and 45 met the inclusion criteria. Studies from 12 countries published over a 12-year period were included. Participants were mainly healthy (n = 23) followed by having a cognitive impairment (n = 10). There were 14 different global positioning system devices used, assessing a variety of outcomes (n = 24). Seventeen studies identified facilitators and barriers to participation and physical activity in an older population. The most common facilitators were safety, weather and access to multi-purpose facilities. The most common barriers were weather, safety, low income/high deprivation areas and use of motor vehicles.Conclusion: This scoping review identified a variety of locational monitoring of older people using global positioning devices. Global positioning systems are a valuable tool to obtain accurate activity locations of older people. There is a need for clear guidelines regarding the use of global positioning system devices and specified outcomes in primary research to enable comparison across studies.Implications for rehabilitationPhysical activity and community participation are vital for healthy ageing.The environment can act as a facilitator or barrier to physical activity and community participation for older adults.Interventions need to target facilitators (weather, safety, facility access and social components) to maximize physical activity and community participation in older people.Interventions should be designed to reduce the barriers (weather, safety, low income and motor vehicle dependency) that prevent older adults from actively participating in their community.

Outdoor Walking Test With a Global Positioning System Device as an Additional Tool for Functional Assessment of Older Women

The primary aim was to assess the test-retest reliability of an outdoor walking test with a global positioning system device in older women in a community setting. In addition, correlations between the suggested test and various tests recommended to evaluate muscle strength, walking speed, and self-perceived health status in older adults were studied. The study included 40 women aged 68 (SD = 5) years. The primary outcomes were total walked distance and mean walking speed. The secondary outcomes were lower-body strength, heart rate, speed in a 4-m walk test, and self-perceived health status. The intraclass correlation coefficients calculated for the total walked distance, mean walking speed, and mean heart rate were .94, .92, and .37, respectively. Thus, the suggested outdoor walking test with the application of a global positioning system device may be considered a reliable test tool, which can be recommended for the evaluation of walking ability among older women in a community setting.

Using global positioning system technology and Google My Maps in follow-up studies-An experience from influenza surveillance study, Chennai, India

A multi-centric influenza surveillance conducted among 1500 elderly participants in Chennai, India, required weekly visits to the participants regularly for three years. Difficulties were faced in locating and navigating to households of the participants due to vast study area, adverse weather conditions and staff attrition, which affected data quality. To overcome these difficulties, we devised a new way of using the 'Global Position System' (GPS) and 'Google My Maps'. GPS coordinates of all participants' households were collected and merged with their demographic data using 'Microsoft excel'. Dataset was uploaded to 'Google My Maps' in appropriate layers. This map was used to locate and navigate to households of the participants and the average working hours in the field reduced by18% even in difficult circumstances. The average number of supervisory visits increased by 150%. This method will greatly facilitate the data collection in cohort based research studies.

Towards meaningful mobility: a research agenda for movement within and between places in later life

Mobility or physical movement contributes to health and wellbeing in later life. Most studies have focused on the contribution of outdoor mobility to active ageing, but physical and cognitive impairments restrict the mobility of many older adults. This article aims to explore the gaps in the current literature on mobility in later life, and identify required innovations in the field through laying out key areas for future research. It discusses two, largely separate, areas of research, namely on mobility patterns and mobility experiences. The first focuses on quantitative and spatial research on outdoor mobility patterns in terms of routes, timing and transport modes. The second mainly concerns qualitative research on how older adults perceive mobility in their everyday lives. This article identifies three areas for future research on mobility in later life: (a) beyond outdoor movement; (b) diversity in mobility; and (c) the role of time in mobility. To conclude, addressing these areas jointly will contribute to further unpacking the concept of mobility as meaningful practice and to integrating quantitative and qualitative methods when studying mobility in later life. This will result in policy inputs on the mobility and wellbeing of our ageing population.

Measuring Community Mobility in Survivors of Stroke Using Global Positioning System Technology: A Prospective Observational Study

BACKGROUND AND PURPOSE

Returning to community mobility is important for people recovering from a stroke, yet few studies have directly measured this construct following inpatient rehabilitation. Using global positioning system (GPS) technology, we examined community mobility of survivors of stroke (SS) over the first year after discharge and compared them to an age-matched comparison group without neurological impairment.

METHODS

We conducted a prospective observational study that included SS (n = 14) and age- and location-matched comparison subjects (CS; n = 6). All participants identified target locations important to their community mobility goals and wore a GPS unit during the first, fifth and ninth weeks after discharge, or from baseline for CS, and at 26 and 52 weeks' follow up. The 6-minute walk test (SMWT), Berg balance test (BBT), Reintegration to Normal Living (RNLI), and Short Form-36 Quality of Life Survey Physical Functioning domain (SF-36-PF) were collected. Number of trips and percentage of targets visited were extracted from GPS data.

RESULTS

Twelve of 14 SS completed 9 weeks, 7 completed the full year, and no CS withdrew. The SS took fewer trips and attained fewer targets compared with CS at weeks 1 and 9, but not at weeks 5, 26, and 52. All 4 clinical outcome measures were significantly correlated to trips (Spearman r for SMWT = 0.5067, BBT = 0.3841, RNLI = 0.4119, and SF-36-PF = 0.4192).

DISCUSSION AND CONCLUSIONS

Directly measured community mobility in SS was decreased through 9 weeks following discharge from inpatient rehabilitation. The limited strength of bivariate correlations between clinical measures and number of trips supported the uniqueness of the community mobility construct.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A277).

Scoping Review: The Trajectory of Recovery of Participation Outcomes following Stroke

Participation is a central concept in health and well-being and healthcare, yet operationalizing this concept has been difficult. Its definition, uses in healthcare, and impacts on recovery require ongoing research. Our review question goes like this: from the longitudinal evidence investigating participation among stroke survivors, what are the patterns of participation recovery in stroke survivors over time, and what interventions are used to improve participation? To fully understand these questions, we also ask, how is participation defined in the stroke literature, and what are the measures of participation used in the stroke literature? A systematic scoping review was undertaken using the search terms "stroke," "longitudinal," "participation," and "outcome" in seven databases. Articles included were published until April 2017, written in English, and had at least two longitudinal assessments of participation. Fifty-nine articles met the inclusion criteria. The International Classification of Functioning, Disability and Health was the most frequent definition of participation used (34%). There were 22 different measures of participation. Eight of ten studies demonstrated significant improvements in participation up to 12 months poststroke. Efficacy of interventions and their impact on participation varied. The various definitions, measures, and intervention efficacies of participation highlight the need for further research worldwide into achieving meaningful participation and quality of life among stroke survivors. Future practice should include participation as a main outcome measure.

Community mobility after stroke: a systematic review

Background Stroke is the leading cause of severe disability and many survivors report long-term physical or cognitive impairments that may impact their ability to achieve community mobility (CM).

PURPOSE

To determine the extent to which people with chronic stroke achieve CM compared to age-matched norms or non-neurologically impaired controls. Methods The StrokEDGE outcome measures were searched to identify validated tools that included >25% of items addressing CM. MEDLINE, CINAHL, Google Scholar, PubMed, PEDro and the Cochrane databases were searched from 2001 to 2015 with the identified outcome measures cross-referenced against search terms related to stroke and CM.

INCLUSION CRITERIA

utilized a validated CM outcome measure, chronic (>3 months post) stroke survivors, and randomized controlled trial, observational or cohort study design. One reviewer screened the studies and performed data extraction and three performed quality appraisal. Fourteen studies met all inclusion criteria. Results Stroke survivors have impaired CM as demonstrated by 30-83% of normative or non-stroke subject CM scores. As time post-stroke increased, CM improved only slightly. Factors found to correlate with the CM were age, education, general well-being, emotional state, motor function and coordination, independence in activities of daily living, balance, endurance and driving status. Limitations of this review include a relatively high functioning cohort, no meta-analysis and reliance on outcome measures not specifically designed to measure CM. Conclusion Survivors of stroke may experience a significant decrease in CM compared to people without neurological injury. Rehabilitation addressing motor function, coordination, independence in activities of daily living, balance and endurance may be important for achieving higher levels of CM. Outcome measures directly addressing CM are needed.

How Physically Active Are People Following Stroke? Systematic Review and Quantitative Synthesis

BACKGROUND

Mobility limitations are common following stroke and frequently lead to poor participation in physical activity (PA).

PURPOSE

The purpose of this study was to describe PA across the various stages following stroke (acute, subacute, and chronic).

DATA SOURCES

Searches were conducted in 5 databases.

STUDY SELECTION

Eligible studies included participants with stroke whose PA was quantitatively measured for at least 4 hours in a single session. Two reviewers independently reviewed titles and abstracts.

DATA EXTRACTION

One reviewer extracted data and assessed quality using the Downs and Black checklist. Weighted means were calculated for PA outcomes.

DATA SYNTHESIS

Searches yielded 103 eligible papers including 5306 participants aged 21 to 96 years. Devices (eg, activity monitors) were used in 73 papers, and behavioral mapping (observational monitoring) in 30. Devices show that people with stroke took on average 5535 steps per day (n = 406, 10 studies) in the subacute phase and 4078 steps (n = 1280, 32 studies) in the chronic phase. Average daily walking duration (% measured time) was higher in the chronic phase (9.0%, n = 100) than subacute (1.8%, n = 172), and sedentary time was >78% regardless of time post stroke. Acute data were lacking for these variables. Matched healthy individuals took an average of 8338 steps per day (n = 129). Behavioral mapping showed time in bed was higher in the acute than subacute phase (mean 45.1% versus 23.8%), with similar time spent sitting (mean 37.6% versus 32.6%).

LIMITATIONS

Limitations of this review include not pooling data reported as medians.

CONCLUSIONS

Physical activity levels do not meet guidelines following stroke. Time spent inactive and sedentary is high at all times. Increasing PA and developing standardized activity targets may be important across all stages of stroke recovery.

Activity Recognition for Persons With Stroke Using Mobile Phone Technology: Toward Improved Performance in a Home Setting

BACKGROUND

Smartphones contain sensors that measure movement-related data, making them promising tools for monitoring physical activity after a stroke. Activity recognition (AR) systems are typically trained on movement data from healthy individuals collected in a laboratory setting. However, movement patterns change after a stroke (eg, gait impairment), and activities may be performed differently at home than in a lab. Thus, it is important to validate AR for gait-impaired stroke patients in a home setting for accurate clinical predictions.

OBJECTIVE

In this study, we sought to evaluate AR performance in a home setting for individuals who had suffered a stroke, by using different sets of training activities. Specifically, we compared AR performance for persons with stroke while varying the origin of training data, based on either population (healthy persons or persons with stoke) or environment (laboratory or home setting).

METHODS

Thirty individuals with stroke and fifteen healthy subjects performed a series of mobility-related activities, either in a laboratory or at home, while wearing a smartphone. A custom-built app collected signals from the phone's accelerometer, gyroscope, and barometer sensors, and subjects self-labeled the mobility activities. We trained a random forest AR model using either healthy or stroke activity data. Primary measures of AR performance were (1) the mean recall of activities and (2) the misclassification of stationary and ambulatory activities.

RESULTS

A classifier trained on stroke activity data performed better than one trained on healthy activity data, improving average recall from 53% to 75%. The healthy-trained classifier performance declined with gait impairment severity, more often misclassifying ambulatory activities as stationary ones. The classifier trained on in-lab activities had a lower average recall for at-home activities (56%) than for in-lab activities collected on a different day (77%).

CONCLUSIONS

Stroke-based training data is needed for high quality AR among gait-impaired individuals with stroke. Additionally, AR systems for home and community monitoring would likely benefit from including at-home activities in the training data.

Are Accelerometers and GPS Devices Valid, Reliable and Feasible Tools for Measurement of Community Ambulation After Stroke?

Purpose: To determine validity, reliability and feasibility of accelerometers (ActivPAL™, Sensewear Pro2Armband) and portable global positioning systems (GPS) (Garmin Forerunner 405CX) for community ambulation measurement after stroke.

Methods: Fifteen community-dwelling stroke survivors attended two sessions; completing a 6-minute walk, treadmill walking, and 200-m outdoor circuit. Feasibility was determined by wearing devices over four days. Measures collected included step count, time spent walking, distance, energy expenditure and location. Intra-class correlation coefficients (ICC), Bland–Altman plots and absolute percentage of error (APE) were used to determine validity and reliability.

Results: ActivPAL™had excellent validity and reliability for most measures (ICC: 0.821–0.999, APE: 0%–11.1%), except for good-excellent findings at speeds < 0.42 m/s (ICC: 0.659–0.894, APE: 1.6%–11.1%). Sensewear had missing values for 23% of recordings and high error for all measures. GPS demonstrated excellent validity and reliability for time spent walking and step count (ICC: 0.805–0.999, APE: 0.9%–10%), and 100% accuracy for location. However, it was not valid or reliable for distance (ICC = −0.139, APE = 23.8%). All devices appeared feasible for community ambulation measurement with assistance for setup and data analysis.

Conclusions: ActivPAL™and Garmin GPS appear valid, reliable and feasible tools for community ambulation measurement after stroke, except for distance. Sensewear demonstrated poor validity and reliability when worn on the paretic arm.

Physical activity measured using global positioning system tracking in non-small cell lung cancer: an observational study

INTRODUCTION

Increasingly physical activity (PA) is being recognized as an important outcome in non-small cell lung cancer (NSCLC). We investigated PA using novel global positioning system (GPS) tracking individuals with NSCLC and a group of similar-aged healthy individuals.

METHODS

A prospective cross-sectional multicenter study. Fifty individuals with NSCLC from 3 Australian tertiary hospitals and 35 similar-aged healthy individuals without cancer were included. Individuals with NSCLC were assessed pretreatment. Primary measures were triaxial accelerometery (steps/day) and GPS tracking (outdoor PA behavior). Secondary measures were questionnaires assessing depression, motivation to exercise, and environmental barriers to PA. Between-group comparisons were analyzed using analysis of covariance.

RESULTS

Individuals with NSCLC engaged in significantly less PA than similar-aged healthy individuals (mean difference 2363 steps/day, P = .007) and had higher levels of depression (P = .027) and lower motivation to exercise (P = .001). Daily outdoor walking time (P = .874) and distance travelled away from home (P = .883) were not different between groups. Individuals with NSCLC spent less time outdoors in their local neighborhood area (P < .001). A greater number of steps per day was seen in patients who were less depressed (r = .39) or had better access to nonresidential destinations such as shopping centers (r = .25).

CONCLUSION

Global positioning system tracking appears to be a feasible methodology for adult cancer patients and holds promise for use in future studies investigating PA and or lifestyle behaviors.

Applicability of global positioning system for the assessment of walking ability in patients with arterial claudication

OBJECTIVE

This study determined for the first time the clinical applicability of a global positioning system (GPS)-monitored community-based walking ability assessment in a large cohort of patients with peripheral artery disease (PAD).

METHODS

A multicenter study was conducted among PAD patients who complained of intermittent claudication. Patients equipped with a GPS device performed a community-based outdoor walk. We determined the number of technically satisfactory GPS recordings (attempt No. 1). Patients with unsatisfactory GPS recordings were asked to perform a second attempt (attempt No. 2). From the satisfactory recordings obtained after attempts No. 1 and No. 2, we analyzed several GPS parameters to provide clinical information on the patients' walking ability. Results are reported as median (interquartile range).

RESULTS

A total of 218 patients performed an outdoor walk. GPS recordings were technically satisfactory in 185 patients (85%) and in 203 (93%) after attempts No. 1 and No. 2, respectively. The highest measured distance between two stops during community walking was 678 m (IQR, 381-1333 m), whereas self-reported maximal walking distance was 250 m (IQR, 150-400 m; P < .001). Walking speed was 3.6 km/h (IQR, 3.1-3.9 km/h), with few variations during the walk. Among the patients who had to stop during the walk, the stop durations were <10 minutes in all but one individual.

CONCLUSIONS

GPS is applicable for the nonsupervised multicenter recording of walking ability in the community. In the future, it may facilitate objective community-based assessment of walking ability, allow for the adequate monitoring of home-based walking programs, and for the study of new dimensions of walking in PAD patients with intermittent claudication.

Global position sensing and step activity as outcome measures of community mobility and social interaction for an individual with a transfemoral amputation due to dysvascular disease

BACKGROUND AND PURPOSE

Community mobility of individuals following lower limb amputation is highly variable and has a great impact on their quality of life. Currently, clinical assessments of ambulatory ability and motivation influence prosthetic prescription. However, these outcome measures do not effectively quantify community mobility (ie, mobility outside of the clinic) of individuals with an amputation. Advances in global positioning systems (GPSs) and other wearable step-monitoring devices allow for objective, quantifiable measurement of community mobility. This case report will examine the combined use of a GPS unit and a step activity monitor to quantify community mobility and social interaction of an individual with transfemoral amputation due to dysvascular disease.

CASE DESCRIPTION

A 76-year-old woman with a unilateral transfemoral amputation due to vascular disease carried a commercial GPS unit and step activity monitor to quantify her community mobility and social interaction every day over a period of 1 month. The step activity monitor was affixed to her prosthesis. The patient used a wheelchair as well as her prosthesis for everyday mobility.

OUTCOME

Information from the GPS unit and step activity monitor provided quantitative details on the patient's steps taken in and out of the home, wheelchair use, prosthesis use, driving trips, and time spent on social and community trips.

DISCUSSION

This case report describes a potential clinical measurement procedure for quantifying community mobility and social interaction of an individual with lower limb amputation. Future efforts are needed to validate this measurement tool on large sample sizes and in individuals with different mobility levels. Additionally, automatization of data analysis and technological approaches to reduce compromised GPS signals may eventually lead to a practical, clinically useful tool.