scholarly journals Concurrent Validity of Inertially Sensed Measures during Voluntary Body Sway in Silence and while Exposed to a Rhythmic Acoustic Stimulus: A Pilot Study

2021 ◽  
pp. 65-73
Author(s):  
Analina Emmanouil ◽  
Elissavet Rousanoglou ◽  
Anastasia Georgaki ◽  
Konstantinos Boudolos

<b><i>Introduction:</i></b> The effect of rhythmic acoustic stimuli on body sway is of increasing interest due to their positive contribution when training or restoring the control of movement. Inertial sensors show promise as a portable, easier, and more affordable method compared to the force plate “gold standard” concerning the evaluation of postural sway. This study examined the concurrent validity of inertially sensed measures of voluntary body sway against those obtained with a force plate, in silence and while exposed to a rhythmic acoustic stimulus. <b><i>Methods:</i></b> Temporal (sway duration and variability) and spatial (trajectory length, variability, range, velocity, and area) body sway variables were extracted using an inertial sensor (at L5) in synchronization with a force plate, during anteroposterior body sway in silence and while exposed to a rhythmic acoustic stimulus (<i>n</i> = 18 young women; two 70-s trials in each condition). Statistics included bivariate correlations between the inertially sensed and the force plate measures, separately, in silence and with a rhythmic acoustic stimulus, as well as for the effect of the rhythmic acoustic stimulus (percentage difference from silence) (<i>p</i> ≤ 0.05, SPSS v25.0). <b><i>Results:</i></b> The inertially sensed measures demonstrated good-to-excellent concurrent validity for all temporal and almost all spatial variables, both in silence and with rhythmic acoustic stimulus (<i>r</i> &#x3e; 0.75, <i>p</i> = 0.000), as well as for the rhythmic acoustic-stimulus effect (<i>r</i> &#x3e; 0.75, <i>p</i> ≤ 0.05). <b><i>Conclusion:</i></b> The inertially sensed measures of the voluntary anteroposterior body sway demonstrated an overall good-to-excellent concurrent validity against those obtained with the force plate “gold standard,” both in the silence and the rhythmic acoustic stimulus conditions, as well as for the rhythmic acoustic-stimulus effect. The findings of this pilot study allow the recommendation of inertial sensing for the evaluation of postural control alterations when exposed to rhythmic acoustic stimuli, a condition of increasing interest due to the positive contribution of such stimuli when training or restoring the control of movement.

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5272
Author(s):  
Nicole Zahradka ◽  
Khushboo Verma ◽  
Ahad Behboodi ◽  
Barry Bodt ◽  
Henry Wright ◽  
...  

Video- and sensor-based gait analysis systems are rapidly emerging for use in ‘real world’ scenarios outside of typical instrumented motion analysis laboratories. Unlike laboratory systems, such systems do not use kinetic data from force plates, rather, gait events such as initial contact (IC) and terminal contact (TC) are estimated from video and sensor signals. There are, however, detection errors inherent in kinematic gait event detection methods (GEDM) and comparative study between classic laboratory and video/sensor-based systems is warranted. For this study, three kinematic methods: coordinate based treadmill algorithm (CBTA), shank angular velocity (SK), and foot velocity algorithm (FVA) were compared to ‘gold standard’ force plate methods (GS) for determining IC and TC in adults (n = 6), typically developing children (n = 5) and children with cerebral palsy (n = 6). The root mean square error (RMSE) values for CBTA, SK, and FVA were 27.22, 47.33, and 78.41 ms, respectively. On average, GED was detected earlier in CBTA and SK (CBTA: −9.54 ± 0.66 ms, SK: −33.41 ± 0.86 ms) and delayed in FVA (21.00 ± 1.96 ms). The statistical model demonstrated insensitivity to variations in group, side, and individuals. Out of three kinematic GEDMs, SK GEDM can best be used for sensor-based gait event detection.


2018 ◽  
Vol 8 (11) ◽  
pp. 191 ◽  
Author(s):  
Osamu Aoki ◽  
Yoshitaka Otani ◽  
Shinichiro Morishita

Gazing at objects at a near distance (small eye-object distance) can reduce body sway. However, whether body sway is regulated by movement in the mediolateral or anteroposterior direction remains unclear. Galvanic vestibular stimulation (GVS) can induce body tilting in the mediolateral or anteroposterior direction. This study examined the directionality of the eye-object distance effect, using body-tilting GVS manipulations. Ten healthy subjects (aged 21.1 ± 0.3 years) stood on a force plate covered with a piece of foamed rubber and either closed their eyes or gazed at a marker located 0.5 m, 1.0 m, or 1.5 m in front of them. The GVS polarities were set to evoke rightward, forward, and backward body tilts. To compare the effects of eye-object distance in the mediolateral and anteroposterior directions, the root mean square (RMS) of the center of pressure (COP) without GVS was subtracted from the COP RMS during GVS. For swaying in the mediolateral direction, significant visual condition-related differences were found during rightward and forward GVS (p < 0.05). Thus, reductions in mediolateral body sway are more evident for smaller eye-object distances during rightward GVS. It would be appropriate to use body-tilting GVS to detect the directionality of the eye-object distance effect.


2017 ◽  
Vol 7 (4) ◽  
Author(s):  
Vivek Velayudhan Nair ◽  
Sunila Thomas ◽  
Jincy Thomas ◽  
Cucoo Mariam Mathew

Osteoporosis characterized by low bone mass/osteopenia can be identified using radiomorphometric indices in routine panoramic radiographs. This study estimates the prevalence of osteopenia in 50-80 years age group, using panoramic mandibular index (PMI), mental index (MI) and mandibular cortical index (MCI). PMI, MI and MCI were applied on 36 panoramic radiographs; MI and MCI were compared with PMI. The prevalence of osteopenia was 11.1% with PMI and 44.4% with MCI. Using MI, the prevalence was 2.8% and 33.3% with 3mm and 4.77mm threshold respectively. The prevalence of osteopenia detected was highest using MCI (44.4%). Considering PMI as gold standard, MI with 4.77 mm threshold showed better agreement with PMI.


Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7497
Author(s):  
Roy T. Shahar ◽  
Maayan Agmon

Spatio-temporal parameters of human gait, currently measured using different methods, provide valuable information on health. Inertial Measurement Units (IMUs) are one such method of gait analysis, with smartphone IMUs serving as a good substitute for current gold-standard techniques. Here we investigate the concurrent validity of a smartphone placed in a front-facing pocket to perform gait analysis. Sixty community-dwelling healthy adults equipped with a smartphone and an application for gait analysis completed a 2-min walk on a marked path. Concurrent validity was assessed against an APDM mobility lab (APDM Inc.; Portland, OR, USA). Bland–Altman plots and intraclass correlation coefficients (agreement and consistency) for gait speed, cadence, and step length indicate good to excellent agreement (ICC2,1 > 0.8). For right leg stance and swing % of gait cycle and double support % of gait cycle, results were moderate (0.52 < ICC2,1 < 0.62). For left leg stance and swing % of gait cycle left results show poor agreement (ICC2,1 < 0.5). Consistency of results was good to excellent for all tested parameters (ICC3,1 > 0.8). Thus we have a valid and reliable instrument for measuring healthy adults’ spatio-temporal gait parameters in a controlled walking environment.


2019 ◽  
Author(s):  
Renaud Hage ◽  
Christine Detrembleur ◽  
Frédéric Dierick ◽  
Laurent Pitance ◽  
Laurent Jojczyk ◽  
...  

Various noninvasive measurement devices can be used to assess cervical motion. Size, complexity and cost of gold-standard systems make them not suited in clinical practice, and actually difficult to use outside dedicated laboratory. Nowadays, ultra-low-cost inertial measurement units are available but without any packaging nor user-friendly interface. DYSKIMOT is a home- designed, small-sized, motion sensor based on the latter technology, aiming at being used by clinicians in “real-life situations”. In the present study. DYSKIMOT was compared with a gold- standard optoelectronic system (Elite). Our goal was to evaluate the accuracy of DYSKIMOT in assessing the kinematics in fast head rotations. Kinematics was simultaneously recorded by the DYSKIMOT and Elite systems during the execution of the DidRen Laser test and performed by 15 participants and 9 patients. Kinematic variables were computed from the position, speed and acceleration time series. Two-way ANOVA, Passing-Bablok regressions and Dynamic Time Warping analysis showed good to excellent agreement between Elite and DYSKIMOT, both at the qualitative level of the time series shape and at the quantitative level of peculiar kinematical events’ measured values. In conclusion, DYSKIMOT sensor is as relevant as a gold-standard system to assess kinematical features during fast head rotations in participants and patients, demonstrating its usefulness in clinical practice or research in ecological environment.


2019 ◽  
Vol 109 (6) ◽  
pp. 416-425 ◽  
Author(s):  
Daniel E. Lidstone ◽  
Louise M. Porcher ◽  
Jessica DeBerardinis ◽  
Janet S. Dufek ◽  
Mohamed B. Trabia

Background: Monitoring footprints during walking can lead to better identification of foot structure and abnormalities. Current techniques for footprint measurements are either static or dynamic, with low resolution. This work presents an approach to monitor the plantar contact area when walking using high-speed videography. Methods: Footprint images were collected by asking the participants to walk across a custom-built acrylic walkway with a high-resolution digital camera placed directly underneath the walkway. This study proposes an automated footprint identification algorithm (Automatic Identification Algorithm) to measure the footprint throughout the stance phase of walking. This algorithm used coloration of the plantar tissue that was in contact with the acrylic walkway to distinguish the plantar contact area from other regions of the foot that were not in contact. Results: The intraclass correlation coefficient (ICC) demonstrated strong agreement between the proposed automated approach and the gold standard manual method (ICC = 0.939). Strong agreement between the two methods also was found for each phase of stance (ICC &gt; 0.78). Conclusions: The proposed automated footprint detection technique identified the plantar contact area during walking with strong agreement with a manual gold standard method. This is the first study to demonstrate the concurrent validity of an automated identification algorithm to measure the plantar contact area during walking.


Author(s):  
Maria Antonieta Tinôco ◽  
Élvio Rúbio Gouveia ◽  
Andreas Ihle ◽  
Adilson Marques ◽  
Bruna R. Gouveia ◽  
...  

Abstract Objectives: To study the reliability/stability of the Cognitive Telephone Screening Instrument (COGTEL) for the assessment of cognitive functions, and to investigate the concurrent validity (that is, the relationship between the COGTEL scores and external variables, such as level of education and MMSE results) in a pilot study of elderly persons residing in the community in the municipal regions of Apuí, Fonte Boa and Manaus (Amazonas, Brazil). Method: This pilot study included 90 elderly persons (29 men and 61 women) aged 60-85 years of age [68.2 (± 6.7)]. The COGTEL, the MMSE and socio-economic survey were applied in the form of two interviews, a week apart and under the same conditions. Results: The test-retest intraclass correlation coefficient of the COGTEL total score (and respective six subtests), MMSE and educational level ranged from acceptable to high (0.708 < R <0.946). There was a strong positive correlation between the total score of the COGTEL with the MMSE (r =0.682; p <0.001), as well as with educational level (r =0.604; p <0.001). Conclusion: This study presents preliminary evidence of the reliability/stability and concurrent validity of the COGTEL in the evaluation of cognitive functions in elderly persons residing in the community. The results of this study support the use of COGTEL as a short, reliable and valid instrument for analyzing differences in cognitive functioning in inter-individual studies with elderly persons.


2011 ◽  
Vol 33 (1) ◽  
pp. 55-82 ◽  
Author(s):  
MICHAEL GROSVALD ◽  
DAVID CORINA

ABSTRACTIn this study we explore listeners' sensitivity to vowel to vowel (VV) coarticulation, using both event-related potential (ERP) and behavioral methodologies. The stimuli used were vowels “colored” by the coarticulatory influence of other vowels across one, three or five intervening segments. The paradigm used in the ERP portion of the study was intended to elicit the mismatch-negativity (MMN) component, a negative deflection typically seen at central midline scalp sites about 200 ms after the presentation of a “deviant” acoustic stimulus occurring among a train of “standard” acoustic stimuli. VV coarticulation at near and medium distances was associated with significant MMN-like effects, which however were not observed in response to the longest distance coarticulatory contrasts. Subjects' ERP results did not predict their performance on the behavioral task, which found evidence of listener sensitivity to even the furthest distance coarticulatory effects. Although the MMN has previously been shown to be sensitive to phonemic contrasts, this is the first study using ERP methodology to investigate the subphonemic processing associated with the perception of coarticulation.


2018 ◽  
Vol 34 (5) ◽  
pp. 410-413 ◽  
Author(s):  
Jason Lake ◽  
Peter Mundy ◽  
Paul Comfort ◽  
John J. McMahon ◽  
Timothy J. Suchomel ◽  
...  

This study examined concurrent validity of countermovement vertical jump reactive strength index modified and force–time characteristics recorded using a 1-dimensional portable and laboratory force plate system. Twenty-eight men performed bilateral countermovement vertical jumps on 2 portable force plates placed on top of 2 in-ground force plates, both recording vertical ground reaction force at 1000 Hz. Time to takeoff; jump height; reactive strength index modified; and braking and propulsion impulse, mean net force, and duration were calculated from the vertical force from both force plate systems. Results from both systems were highly correlated (r ≥ .99). There were small (d < 0.12) but significant differences between their respective braking impulse, braking mean net force, propulsion impulse, and propulsion mean net force (P < .001). However, limits of agreement yielded a mean value of 1.7% relative to the laboratory force plate system (95% confidence limits, 0.9%–2.5%), indicating very good agreement across all of the dependent variables. The largest limits of agreement were for jump height (2.1%), time to takeoff (3.4%), and reactive strength index modified (3.8%). The portable force plate system provides a valid method of obtaining reactive strength measures, and several underpinning force–time variables, from unloaded countermovement vertical jump. Thus, practitioners can use both force plates interchangeably.


2008 ◽  
Vol 32 (4) ◽  
pp. 422-433 ◽  
Author(s):  
Nerrolyn Ramstrand ◽  
Christina Björk Andersson ◽  
David Rusaw

This study aimed to investigate if prolonged use of shoes incorporating an unstable sole construction could facilitate improvements of balance in a sample of developmentally disabled children. Ten children (six male and four female) aged between 10 and 17 years participated in the study. Children were fitted with shoes incorporating an unstable sole (Masai Barefoot Technology®) and instructed to wear them for a minimum of two hours per day for eight weeks. A within subjects repeated measures design was used. Children were tested prior to receiving the shoes, four weeks after receiving the shoes and eight weeks after receiving the shoes. A force plate capable of rotating about a single axis (NeuroCom International Inc, Oregon) was used to test static balance, reactive balance and directional control. Static balance was not found to be influenced by prolonged use of the footwear; however, significant improvements were noted in children's reactive balance both with the shoes and barefoot. Results suggest that reactive balance can be improved by prolonged and regular use of shoes incorporating an unstable sole construction.


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