Sit-To-Stand Movement Evaluated Using an Inertial Measurement Unit Embedded in Smart Glasses—A Validation Study
TL;DR: Observations indicate that the IMU embedded in smart glasses is accurate to measure vertical acceleration during STS movements to assess the STS movement in unstandardized settings and to report vertical acceleration values in an elderly population of fallers and non-fallers.
Abstract: Wearable sensors have recently been used to evaluate biomechanical parameters of everyday movements, but few have been located at the head level. This study investigated the relative and absolute reliability (intra- and inter-session) and concurrent validity of an inertial measurement unit (IMU) embedded in smart eyeglasses during sit-to-stand (STS) movements for the measurement of maximal acceleration of the head. Reliability and concurrent validity were investigated in nineteen young and healthy participants by comparing the acceleration values of the glasses’ IMU to an optoelectronic system. Sit-to-stand movements were performed in laboratory conditions using standardized tests. Participants wore the smart glasses and completed two testing sessions with STS movements performed at two speeds (slow and comfortable) under two different conditions (with and without a cervical collar). Both the vertical and anteroposterior acceleration values were collected and analyzed. The use of the cervical collar did not significantly influence the results obtained. The relative reliability intra- and inter-session was good to excellent (i.e., intraclass correlation coefficients were between 0.78 and 0.91) and excellent absolute reliability (i.e., standard error of the measurement lower than 10% of the average test or retest value) was observed for the glasses, especially for the vertical axis. Whatever the testing sessions in all conditions, significant correlations (p < 0.001) were found for the acceleration values recorded either in the vertical axis and in the anteroposterior axis between the glasses and the optoelectronic system. Concurrent validity between the glasses and the optoelectronic system was observed. Our observations indicate that the IMU embedded in smart glasses is accurate to measure vertical acceleration during STS movements. Further studies should investigate the use of these smart glasses to assess the STS movement in unstandardized settings (i.e., clinical and/or home) and to report vertical acceleration values in an elderly population of fallers and non-fallers.
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01 Jan 2013
TL;DR: In this article, the authors measured the variability of the accelerations, angular velocity, and displacement of the trunk during the Sit-to-Sit and Stand-To-Sit transitions in two groups of frail and physically active elderly persons, through instrumentation with the iPhone 4 smartphone.
Abstract: Background - Clinical frailty syndrome is a common geriatric syndrome, which is characterized by physiological reserve decreases and increased vulnerability. The changes associated to ageing and frailties are associated to changes in gait characteristics and the basic functional capacities. Traditional clinical evaluation of Sit-to-Stand (Si-St) and Stand-to-Sit (St-Si) transition is based on visual observation of joint angle motion to describe alterations in coordination and movement pattern. The latest generation smartphones often include inertial sensors with subunits such as accelerometers and gyroscopes, which can detect acceleration.
Objective - Firstly, to describe the variability of the accelerations, angular velocity, and displacement of the trunk during the Sit-to-Stand and Stand-to-Sit transitions in two groups of frail and physically active elderly persons, through instrumentation with the iPhone 4 smartphone. Secondly, we want to analyze the differences between the two study groups.
Methods - A cross-sectional study that involved 30 subjects over 65 years, 14 frail and 16 fit subjects. The participants were classified with frail syndrome by the Fried criteria. Linear acceleration was measured along three orthogonal axes using the iPhone 4 accelerometer. Each subject performed up to three successive Si-St and St-Si postural transitions using a standard chair with armrest.
Results - Significant differences were found between the two groups of frail and fit elderly persons in the accelerometry and angular displacement variables obtained in the kinematic readings of the trunk during both transitions.
Conclusions - The inertial sensor fitted in the iPhone 4 is able to study and analyze the kinematics of the Si-St and St-Si transitions in frail and physically active elderly persons. The accelerometry values for the frail elderly are lower than for the physically active elderly, while variability in the readings for the frail elderly is also lower than for the control group.
6 citations
TL;DR: Investigation of a wireless earbud-type inertial measurement unit sensor used to estimate head angle indicated that the validity of the Ear-IMU sensor was very strong or moderate in the sagittal and frontal planes and can be used to directly estimate head motion and indirectly estimate trunk motion.
Abstract: The present study was performed to investigate the validity of a wireless earbud-type inertial measurement unit (Ear-IMU) sensor used to estimate head angle during four workouts. In addition, relationships between head angle obtained from the Ear-IMU sensor and the angles of other joints determined with a 3D motion analysis system were investigated. The study population consisted of 20 active volunteers. The Ear-IMU sensor measured the head angle, while a 3D motion analysis system simultaneously measured the angles of the head, trunk, pelvis, hips, and knees during workouts. Comparison with the head angle measured using the 3D motion analysis system indicated that the validity of the Ear-IMU sensor was very strong or moderate in the sagittal and frontal planes. In addition, the trunk angle in the frontal plane showed a fair correlation with the head angle determined with the Ear-IMU sensor during a single-leg squat, reverse lunge, and standing hip abduction; the correlation was poor in the sagittal plane. Our results indicated that the Ear-IMU sensor can be used to directly estimate head motion and indirectly estimate trunk motion.
4 citations
TL;DR: In this paper , the validity and reproducibility of step duration and step length parameters measured during walking in healthy participants using an accelerometer embedded in smart eyeglasses was determined using two identical sessions comprising a 30 s gait assessment performed at three different treadmill speeds.
Abstract: The study aims to determine the validity and reproducibility of step duration and step length parameters measured during walking in healthy participants using an accelerometer embedded in smart eyeglasses. Twenty young volunteers participated in two identical sessions comprising a 30 s gait assessment performed at three different treadmill speeds under two conditions (i.e., with and without a cervical collar). Spatiotemporal parameters (i.e., step duration and step length normalized by the lower limb length) were obtained with both the accelerometer embedded in smart eyeglasses and an optoelectronic system. The relative intra- and inter-session reliability of step duration and step length computed from the vertical acceleration data were excellent for all experimental conditions. An excellent absolute reliability was observed for the eyeglasses for all conditions and concurrent validity between systems was observed. An accelerometer incorporated in smart eyeglasses is accurate to measure step duration and step length during gait.
3 citations
TL;DR: In this article, a sit-to-stand test (STS) was developed to measure force velocity (F-v) and power velocity (P-v), and the concurrent validity of STS was tested using Spearman's rank correlation coefficient and Passing Bablok.
2 citations
Proceedings Article•
01 Jun 2022
TL;DR: In this paper , a low-complex decision tree algorithm was used to detect sit-to-stand and stand-to sit postural transitions in addition to other human physical activities such as walk and no-walk.
Abstract: Monitoring and analyzing basic human daily life activities will help in enhancing the quality of life for both healthy and physically handicapped people. The recognition of sit-to-stand and stand-to-sit transitions in activities of daily living (ADL) is complex task. This is due to the intricate body’s movements during such postural transition. This work proposes a novel method for detecting sit-to-stand and stand-to-sit postural transitions in addition to other human physical activities such as walk and no-walk. In contrast to previous methods for such transitions determination, our solution does not require complex time- or frequency-domain based algorithms. Our solution relies on fusing motion data collected from an inertial measurement unit device with light data generated from visible light sensing technology utilizing an RGB photodiode. By utilizing a low-complex decision tree algorithm, the activity can be precisely recognized in resource-efficient way. The applicability of our approach was tested through two scenarios representing various ADL in smart environment.
2 citations
References
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TL;DR: An alternative approach, based on graphical techniques and simple calculations, is described, together with the relation between this analysis and the assessment of repeatability.
43,884 citations
"Sit-To-Stand Movement Evaluated Usi..." refers methods in this paper
...Then, Bland–Altman graphs with 95% limits of agreement were plotted to compare the maximal acceleration values of both systems [41]....
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TL;DR: A practical guideline for clinical researchers to choose the correct form of ICC is provided and the best practice of reporting ICC parameters in scientific publications is suggested.
12,717 citations
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TL;DR: In this article, an alternative approach, based on graphical techniques and simple calculations, is described, together with the relation between this analysis and the assessment of repeatability, which is often used in clinical comparison of a new measurement technique with an established one.
9,160 citations
TL;DR: Evidence is presented that performance measures can validly characterize older persons across a broad spectrum of lower extremity function and that performance and self-report measures may complement each other in providing useful information about functional status.
Abstract: Background A short battery of physical performance tests was used to assess lower extremity function in more than 5,000 persons age 71 years and older in three communities. Methods Balance, gait, strength, and endurance were evaluated by examining ability to stand with the feet together in the side-by-side, semi-tandem, and tandem positions, time to walk 8 feet, and time to rise from a chair and return to the seated position 5 times. Results A wide distribution of performance was observed for each test. Each test and a summary performance scale, created by summing categorical rankings of performance on each test, were strongly associated with self-report of disability. Both self-report items and performance tests were independent predictors of short-term mortality and nursing home admission in multivariate analyses. However, evidence is presented that the performance tests provide information not available from self-report items. Of particular importance is the finding that in those at the high end of the functional spectrum, who reported almost no disability, the performance test scores distinguished a gradient of risk for mortality and nursing home admission. Additionally, within subgroups with identical self-report profiles, there were systematic differences in physical performance related to age and sex. Conclusion This study provides evidence that performance measures can validly characterize older persons across a broad spectrum of lower extremity function. Performance and self-report measures may complement each other in providing useful information about functional status.
7,417 citations
"Sit-To-Stand Movement Evaluated Usi..." refers methods in this paper
..., the duration to perform five [4] or ten [5] consecutive STS movements or the maximum number of STS movements performed in thirty seconds [6] or one minute [7]) is widely used to assess functional capacities of different populations in clinical settings [8,9]....
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TL;DR: In this review, the basics of classic reliability theory are addressed in the context of choosing and interpreting an ICC and how the SEM and its variants can be used to construct confidence intervals for individual scores and to determine the minimal difference needed to be exhibited for one to be confident that a true change in performance of an individual has occurred.
Abstract: Reliability, the consistency of a test or measurement, is frequently quantified in the movement sciences literature. A common metric is the intraclass correlation coefficient (ICC). In addition, the SEM, which can be calculated from the ICC, is also frequently reported in reliability studies. However, there are several versions of the ICC, and confusion exists in the movement sciences regarding which ICC to use. Further, the utility of the SEM is not fully appreciated. In this review, the basics of classic reliability theory are addressed in the context of choosing and interpreting an ICC. The primary distinction between ICC equations is argued to be one concerning the inclusion (equations 2,1 and 2,k) or exclusion (equations 3,1 and 3,k) of systematic error in the denominator of the ICC equation. Inferential tests of mean differences, which are performed in the process of deriving the necessary variance components for the calculation of ICC values, are useful to determine if systematic error is present. If so, the measurement schedule should be modified (removing trials where learning and/or fatigue effects are present) to remove systematic error, and ICC equations that only consider random error may be safely used. The use of ICC values is discussed in the context of estimating the effects of measurement error on sample size, statistical power, and correlation attenuation. Finally, calculation and application of the SEM are discussed. It is shown how the SEM and its variants can be used to construct confidence intervals for individual scores and to determine the minimal difference needed to be exhibited for one to be confident that a true change in performance of an individual has occurred.
3,992 citations
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...Moreover, we also observed that the SEM for all testing conditions and sessions was smaller than 10%, indicating excellent absolute reliability [37]....
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