The Validity of Gait Variability and Fractal Dynamics Obtained From a Single, Body-Fixed Triaxial Accelerometer

A single triaxial accelerometer has the ability to collect a large amount of continuous gait data to quantitatively assess the control of gait. Unfortunately, there is limited information on the validity of gait variability and fractal dynamics obtained from this device. The purpose of this study was to test the concurrent validity of the variability and fractal dynamic measures of gait provided by a triaxial accelerometer during a continuous 10 minute walk in older adults. Forty-one healthy older adults were fitted with a single triaxial accelerometer at the waist, as well as a criterion footswitch device before completing a ten minute overground walk. The concurrent validity of six outcome measures was examined using intraclass correlation coefficients (ICC) and 95% limits of agreement. All six dependent variables measured by the accelerometer displayed excellent agreement with the footswitch device. Mean parameters displayed the highest validity, followed by measures of variability and fractal dynamics in stride times and measures of variability and fractal dynamics in step times. These findings suggest that an accelerometer is a valid and unique device that has the potential to provide clinicians with valid quantitative data for assessing their clients’ gait.

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Concurrent Validity of the Garmin Vivofit®4 to Accurately Record Step Count in Older Adults in Challenging Environments

Journal of Aging and Physical Activity ◽

10.1123/japa.2021-0231 ◽

2021 ◽

pp. 1-9

Author(s):

Jacinta I. Foster ◽

Katrina L. Williams ◽

Barbra H.B. Timmer ◽

Sandra G. Brauer

Keyword(s):

Older Adults ◽

Concurrent Validity ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Error Rates ◽

Percentage Error ◽

Battery Life ◽

Intraclass Correlation Coefficients ◽

Outdoor Walking ◽

Walking Speeds

There is little evidence of the concurrent validity of commercially available wrist-worn long battery life activity monitors to measure steps in older adults at slow speeds and with real-world challenges. Forty adults aged over 60 years performed a treadmill protocol at four speeds, a 50-m indoor circuit, and a 200-m outdoor circuit with environmental challenges while wearing a Garmin Vivofit®4, the activPAL3™, and a chest-worn camera angled at the feet. The Garmin Vivofit®4 showed high intraclass correlation coefficients2,1 (.98–.99) and low absolute percentage error rates (<2%) at the fastest treadmill speeds and the outdoor circuit. Step counts were underestimated at the slowest treadmill speed and the indoor circuit. The Garmin Vivofit®4 is accurate for older adults at higher walking speeds and during outdoor walking. However, it underestimates steps at slow speeds and when walking indoors with postural transitions.

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Validity of Inertial Sensors for Assessing Balance Kinematics and Mobility during Treadmill-Based Perturbation and Dance Training

Sensors ◽

10.3390/s21093065 ◽

2021 ◽

Vol 21 (9) ◽

pp. 3065

Author(s):

Ernest Kwesi Ofori ◽

Shuaijie Wang ◽

Tanvi Bhatt

Keyword(s):

Concurrent Validity ◽

Inertial Sensors ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Human Motion ◽

Intraclass Correlation Coefficients ◽

Dance Training ◽

Silver Standard ◽

Mean Square Errors ◽

Reactive Balance

Inertial sensors (IS) enable the kinematic analysis of human motion with fewer logistical limitations than the silver standard optoelectronic motion capture (MOCAP) system. However, there are no data on the validity of IS for perturbation training and during the performance of dance. The aim of this present study was to determine the concurrent validity of IS in the analysis of kinematic data during slip and trip-like perturbations and during the performance of dance. Seven IS and the MOCAP system were simultaneously used to capture the reactive response and dance movements of fifteen healthy young participants (Age: 18–35 years). Bland Altman (BA) plots, root mean square errors (RMSE), Pearson’s correlation coefficients (R), and intraclass correlation coefficients (ICC) were used to compare kinematic variables of interest between the two systems for absolute equivalency and accuracy. Limits of agreements (LOA) of the BA plots ranged from −0.23 to 0.56 and −0.21 to 0.43 for slip and trip stability variables, respectively. The RMSE for slip and trip stabilities were from 0.11 to 0.20 and 0.11 to 0.16, respectively. For the joint mobility in dance, LOA varied from −6.98–18.54, while RMSE ranged from 1.90 to 13.06. Comparison of IS and optoelectronic MOCAP system for reactive balance and body segmental kinematics revealed that R varied from 0.59 to 0.81 and from 0.47 to 0.85 while ICC was from 0.50 to 0.72 and 0.45 to 0.84 respectively for slip–trip perturbations and dance. Results of moderate to high concurrent validity of IS and MOCAP systems. These results were consistent with results from similar studies. This suggests that IS are valid tools to quantitatively analyze reactive balance and mobility kinematics during slip–trip perturbation and the performance of dance at any location outside, including the laboratory, clinical and home settings.

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Using Pedometers to Estimate Ambulatory Physical Activity in Vietnam

Journal of Physical Activity and Health ◽

10.1123/jpah.8.1.52 ◽

2011 ◽

Vol 8 (1) ◽

pp. 52-61 ◽

Cited By ~ 2

Author(s):

Au Bich Thuy ◽

Leigh Blizzard ◽

Michael Schmidt ◽

Costan Magnussen ◽

Emily Hansen ◽

...

Keyword(s):

Physical Activity ◽

Concurrent Validity ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Population Based ◽

Work Activities ◽

Intraclass Correlation Coefficients ◽

Significant Difference ◽

Day Of The Week ◽

Population Based Survey

Background:Pedometer measurement of physical activity (PA) has been shown to be reliable and valid in industrialized populations, but its applicability in economically developing Vietnam remains untested. This study assessed the feasibility, stability and validity of pedometer estimates of PA in Vietnam.Methods:250 adults from a population-based survey were randomly selected to wear Yamax pedometers and record activities for 7 consecutive days. Stability and concurrent validity were assessed using intraclass correlation coefficients (ICC) and Spearman correlation coefficients.Results:Overall, 97.6% of participants provided at least 1 day of usable recordings, and 76.2% wore pedometers for all 7 days. Only 5.2% of the sample participants were involved in work activities not measurable by pedometer. The number of steps increased with hours of wear. There was no significant difference between weekday and weekend in number of steps, and at least 3 days of recordings were required (ICC of the 3 days of recordings: men 0.96, women 0.97). Steps per hour were moderately correlated (men r = .42, women r = .26) with record estimates of total PA.Conclusions:It is feasible to use pedometers to estimate PA in Vietnam. The measure should involve at least 3 days of recording irrespective of day of the week.

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Reliability, Internal Consistency, and Validity of Data Obtained With the Functional Gait Assessment

Physical Therapy ◽

10.1093/ptj/84.10.906 ◽

2004 ◽

Vol 84 (10) ◽

pp. 906-918 ◽

Cited By ~ 267

Author(s):

Diane M Wrisley ◽

Gregory F Marchetti ◽

Diane K Kuharsky ◽

Susan L Whitney

Keyword(s):

Internal Consistency ◽

Concurrent Validity ◽

Physical Therapist ◽

Rank Order ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Vestibular Disorders ◽

Intraclass Correlation Coefficients ◽

Gait Assessment ◽

Functional Gait

Background and Purpose. The Functional Gait Assessment (FGA) is a 10-item gait assessment based on the Dynamic Gait Index. The purpose of this study was to evaluate the reliability, internal consistency, and validity of data obtained with the FGA when used with people with vestibular disorders. Subjects. Seven physical therapists from various practice settings, 3 physical therapist students, and 6 patients with vestibular disorders volunteered to participate. Methods. All raters were given 10 minutes to review the instructions, the test items, and the grading criteria for the FGA. The 10 raters concurrently rated the performance of the 6 patients on the FGA. Patients completed the FGA twice, with an hour's rest between sessions. Reliability of total FGA scores was assessed using intraclass correlation coefficients (2,1). Internal consistency of the FGA was assessed using the Cronbach alpha and confirmatory factor analysis. Concurrent validity was assessed using the correlation of the FGA scores with balance and gait measurements. Results. Intraclass correlation coefficients of .86 and .74 were found for interrater and intrarater reliability of the total FGA scores. Internal consistency of the FGA scores was .79. Spearman rank order correlation coefficients of the FGA scores with balance measurements ranged from .11 to .67. Discussion and Conclusion. The FGA demonstrates what we believe is acceptable reliability, internal consistency, and concurrent validity with other balance measures used for patients with vestibular disorders.

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Gait Variability Using Waist- and Ankle-Worn Inertial Measurement Units in Healthy Older Adults

Sensors ◽

10.3390/s20102858 ◽

2020 ◽

Vol 20 (10) ◽

pp. 2858 ◽

Cited By ~ 1

Author(s):

Timo Rantalainen ◽

Laura Karavirta ◽

Henrikki Pirkola ◽

Taina Rantanen ◽

Vesa Linnamo

Keyword(s):

Older Adults ◽

Correlation Coefficient ◽

Concurrent Validity ◽

Force Plate ◽

Gait Variability ◽

Inertial Measurement Units ◽

Healthy Older Adults ◽

Inertial Measurement ◽

Measurement Units ◽

Stride Duration

Gait variability observed in step duration is predictive of impending adverse health outcomes among apparently healthy older adults and could potentially be evaluated using wearable sensors (inertial measurement units, IMU). The purpose of the present study was to establish the reliability and concurrent validity of gait variability and complexity evaluated with a waist and an ankle-worn IMU. Seventeen women (age 74.8 (SD 44) years) and 10 men (73.7 (4.1) years) attended two laboratory measurement sessions a week apart. Their stride duration variability was concurrently evaluated based on a continuous 3 min walk using a force plate and a waist- and an ankle-worn IMU. Their gait complexity (multiscale sample entropy) was evaluated from the waist-worn IMU. The force plate indicated excellent stride duration variability reliability (intra-class correlation coefficient, ICC = 0.90), whereas fair to good reliability (ICC = 0.47 to 0.66) was observed from the IMUs. The IMUs exhibited poor to excellent concurrent validity in stride duration variability compared to the force plate (ICC = 0.22 to 0.93). A good to excellent reliability was observed for gait complexity in most coarseness scales (ICC = 0.60 to 0.82). A reasonable congruence with the force plate-measured stride duration variability was observed on many coarseness scales (correlation coefficient = 0.38 to 0.83). In conclusion, waist-worn IMU entropy estimates may provide a feasible indicator of gait variability among community-dwelling ambulatory older adults.

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A Digital Photographic Measurement Method for Quantifying Foot Posture: Validity, Reliability, and Descriptive Data

Journal of Athletic Training ◽

10.4085/1062-6050-46.1.20 ◽

2011 ◽

Vol 46 (1) ◽

pp. 20-30 ◽

Cited By ~ 17

Author(s):

Stephen C. Cobb ◽

C. Roger James ◽

Matthew Hjertstedt ◽

James Kruk

Keyword(s):

Concurrent Validity ◽

Measurement Method ◽

Injury Risk ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Validity And Reliability ◽

Descriptive Data ◽

Data Set ◽

Intraclass Correlation Coefficients ◽

Foot Posture

Abstract Context: Although abnormal foot posture long has been associated with lower extremity injury risk, the evidence is equivocal. Poor intertester reliability of traditional foot measures might contribute to the inconsistency. Objectives: To investigate the validity and reliability of a digital photographic measurement method (DPMM) technology, the reliability of DPMM-quantified foot measures, and the concurrent validity of the DPMM with clinical-measurement methods (CMMs) and to report descriptive data for DPMM measures with moderate to high intratester and intertester reliability. Design: Descriptive laboratory study. Setting: Biomechanics research laboratory. Patients or Other Participants: A total of 159 people participated in 3 groups. Twenty-eight people (11 men, 17 women; age = 25 ± 5 years, height = 1.71 ± 0.10 m, mass = 77.6 ± 17.3 kg) were recruited for investigation of intratester and intertester reliability of the DPMM technology; 20 (10 men, 10 women; age = 24 ± 2 years, height = 1.71 ± 0.09 m, mass = 76 ± 16 kg) for investigation of DPMM and CMM reliability and concurrent validity; and 111 (42 men, 69 women; age = 22.8 ± 4.7 years, height = 168.5 ± 10.4 cm, mass = 69.8 ± 13.3 kg) for development of a descriptive data set of the DPMM foot measurements with moderate to high intratester and intertester reliabilities. Intervention(s): The dimensions of 10 model rectangles and the 28 participants' feet were measured, and DPMM foot posture was measured in the 111 participants. Two clinicians assessed the DPMM and CMM foot measures of the 20 participants. Main Outcome Measure(s): Validity and reliability were evaluated using mean absolute and percentage errors and intraclass correlation coefficients. Descriptive data were computed from the DPMM foot posture measures. Results: The DPMM technology intratester and intertester reliability intraclass correlation coefficients were 1.0 for each tester and variable. Mean absolute errors were equal to or less than 0.2 mm for the bottom and right-side variables and 0.1° for the calculated angle variable. Mean percentage errors between the DPMM and criterion reference values were equal to or less than 0.4%. Intratester and intertester reliabilities of DPMM-computed structural measures of arch and navicular indices were moderate to high (>0.78), and concurrent validity was moderate to strong. Conclusions: The DPMM is a valid and reliable clinical and research tool for quantifying foot structure. The DPMM and the descriptive data might be used to define groups in future studies in which the relationship between foot posture and function or injury risk is investigated.

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Psychometrics of the Wrist Stability and Hand Mobility Subscales of the Fugl-Meyer Assessment in Moderately Impaired Stroke

Physical Therapy ◽

10.2522/ptj.20130235 ◽

2015 ◽

Vol 95 (1) ◽

pp. 103-108 ◽

Cited By ~ 19

Author(s):

Stephen J. Page ◽

Erinn Hade ◽

Andrew Persch

Keyword(s):

Upper Extremity ◽

Internal Consistency ◽

Concurrent Validity ◽

Intraclass Correlation ◽

Rank Correlation ◽

Correlation Coefficients ◽

Outpatient Rehabilitation ◽

Finger Movement ◽

Intraclass Correlation Coefficients ◽

Upper Extremity Movement

Background There remains a need for a quickly administered, stroke-specific, bedside measure of active wrist and finger movement for the expanding stroke population. The wrist stability and hand mobility scales of the upper extremity Fugl-Meyer Assessment (w/h UE FM) constitute a valid, reliable measure of paretic UE impairment in patients with active wrist and finger movement. Objective The aim of this study was to determine performance on the w/h UE FM in a stable cohort of survivors of stroke with only palpable movement in their paretic wrist flexors. Design A single-center cohort study was conducted. Method Thirty-two individuals exhibiting stable, moderate upper extremity hemiparesis (15 male, 17 female; mean age=56.6 years, SD=10.1; mean time since stroke=4.6 years, SD=5.8) participated in the study, which was conducted at an outpatient rehabilitation clinic in the midwestern United States. The w/h UE FM and Action Research Arm Test (ARAT) were administered twice. Intraclass correlation coefficients (ICCs), Cronbach alpha, and ordinal alpha were computed to determine reliability, and Spearman rank correlation coefficients and Bland-Altman plots were computed to establish validity. Results Intraclass correlation coefficients for the w/h UE FM and ARAT were .95 and .99, respectively. The w/h UE FM intrarater reliability and internal consistency were greater than .80, and concurrent validity was greater than .70. This also was the first stroke rehabilitative study to apply ordinal alpha to examine internal consistency values, revealing w/h UE FM levels greater than .85. Concurrent validity findings were corroborated by Bland-Altman plots. Conclusions It appears that the w/h UE FM is a promising tool to measure distal upper extremity movement in patients with little active paretic wrist and finger movement. This finding widens the segment of patients on whom the w/h UE FM can be effectively used and addresses a gap, as commonly used measures necessitate active distal upper extremity movement.

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Agreement between an online dietary assessment tool (myfood24) and an interviewer-administered 24-h dietary recall in British adolescents aged 11–18 years

British Journal Of Nutrition ◽

10.1017/s0007114516000593 ◽

2016 ◽

Vol 115 (9) ◽

pp. 1678-1686 ◽

Cited By ~ 28

Author(s):

Salwa A. Albar ◽

Nisreen A. Alwan ◽

Charlotte E. L. Evans ◽

Darren C. Greenwood ◽

Janet E. Cade

Keyword(s):

Assessment Tool ◽

New Technology ◽

Dietary Assessment ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Limited Information ◽

Dietary Recall ◽

Face To Face ◽

Intraclass Correlation Coefficients ◽

Adolescents And Adults

Abstractmyfood24 Is an online 24-h dietary assessment tool developed for use among British adolescents and adults. Limited information is available regarding the validity of using new technology in assessing nutritional intake among adolescents. Thus, a relative validation of myfood24 against a face-to-face interviewer-administered 24-h multiple-pass recall (MPR) was conducted among seventy-five British adolescents aged 11–18 years. Participants were asked to complete myfood24 and an interviewer-administered MPR on the same day for 2 non-consecutive days at school. Total energy intake (EI) and nutrients recorded by the two methods were compared using intraclass correlation coefficients (ICC), Bland–Altman plots (using between and within-individual information) and weighted κ to assess the agreement. Energy, macronutrients and other reported nutrients from myfood24 demonstrated strong agreement with the interview MPR data, and ICC ranged from 0·46 for Na to 0·88 for EI. There was no significant bias between the two methods for EI, macronutrients and most reported nutrients. The mean difference between myfood24 and the interviewer-administered MPR for EI was −230 kJ (−55 kcal) (95 % CI −490, 30 kJ (−117, 7 kcal); P=0·4) with limits of agreement ranging between 39 % (3336 kJ (−797 kcal)) lower and 34 % (2874 kJ (687 kcal)) higher than the interviewer-administered MPR. There was good agreement in terms of classifying adolescents into tertiles of EI (κw=0·64). The agreement between day 1 and day 2 was as good for myfood24 as for the interviewer-administered MPR, reflecting the reliability of myfood24. myfood24 Has the potential to collect dietary data of comparable quality with that of an interviewer-administered MPR.

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Map-based assessment of older adults’ life space: validity and reliability

European Review of Aging and Physical Activity ◽

10.1186/s11556-020-00253-7 ◽

2020 ◽

Vol 17 (1) ◽

Author(s):

Timo Hinrichs ◽

Adriana Zanda ◽

Michelle P. Fillekes ◽

Pia Bereuter ◽

Erja Portegijs ◽

...

Keyword(s):

Older Adults ◽

Confidence Interval ◽

Convex Hull ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Maximum Distance ◽

Validity And Reliability ◽

Life Space ◽

Intraclass Correlation Coefficients ◽

Test Retest Reliability

Abstract Background Map-based tools have recently found their way into health-related research. They can potentially be used to quantify older adults’ life-space. This study aimed to evaluate the validity (vs. GPS) and the test-retest reliability of a map-based life-space assessment (MBA). Methods Life-space of one full week was assessed by GPS and by MBA. MBA was repeated after approximately 3 weeks. Distance-related (mean and maximum distance from home) and area-related (convex hull, standard deviational ellipse) life-space indicators were calculated. Intraclass correlations (MBA vs. GPS and test-retest) were calculated in addition to Bland-Altman analyses (MBA vs. GPS). Results Fifty-eight older adults (mean age 74, standard deviation 5.5 years; 39.7% women) participated in the study. Bland-Altman analyses showed the highest agreement between methods for the maximum distance from home. Intraclass correlation coefficients ranged between 0.19 (95% confidence interval 0 to 0.47) for convex hull and 0.72 (95% confidence interval 0.52 to 0.84) for maximum distance from home. Intraclass correlation coefficients for test-retest reliability ranged between 0.04 (95% confidence interval 0 to 0.30) for convex hull and 0.43 (95% confidence interval 0.19 to 0.62) for mean distance from home. Conclusions While acceptable validity and reliability were found for the distance-related life-space parameters, MBA cannot be recommended for the assessment of area-related life-space parameters.

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Acceptability and Feasibility of ActivPAL Activity Tracker for Pre-Frail African American Older Adults

Innovation in Aging ◽

10.1093/geroni/igaa057.622 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

pp. 192-192

Author(s):

Yi-Ling Hu ◽

Camila Rodriguez Valenzuela ◽

Ryan Jones ◽

Natalie Gamalski ◽

Heather Fritz

Keyword(s):

Older Adults ◽

African American ◽

Skin Irritation ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Health Issues ◽

Intraclass Correlation Coefficients ◽

Activity Tracker ◽

Activity Trackers ◽

Data Tracking

Abstract Frailty is more prevalent among African American (AA) older adults compared to their White counterparts. Physical activity (PA) interventions are effective to attenuate frailty progression. The Activpal is adhered to the thigh and allows unobtrusive PA measurement for up to 14 days. However, few studies have tested the acceptability and feasibility of activity trackers among older pre-frail AA. In this study, pre-frail AA older adults were asked to wear the ActivPAL tracker on their thigh for 7 consecutive days. Acceptability was measured by compliance. Feasibility was evaluated by the valid number of days and programing errors. Intraclass correlation coefficients were used to assess the agreement of light to vigorous PA level between ActivPAL and the Community Healthy Activities Model Program for Seniors (CHAMPS). In a sample of 28 pre-frail AA older adults (mean age= 73.21,SD= 9.37, 100% female), 24 completed the 7-day data tracking. Reasons for non-compliance included skin irritation (n=1), and fear of causing other health issues (n=3). The number of valid days was= 6.9 0.33 with 1 incident of programming error. The agreement between ActivPAL and CHAMPS was fair (ICC =0.57, [95%CI]= -.08 -.85) with most participants (61.6%) over-reporting PA on CHAMPS. The ActivPAL accelerometer was acceptable and feasible to use among pre-frail AA older adults. Communication prior to applying the accelerometer is crucial to prevent non-compliance. The results confirm prior studies, which suggest that older adults may over-report PA levels. ActivPAL offers a feasible and accurate approach to assess PA among older AA.

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