scholarly journals Validation of gyroscope sensors for snow sports performance monitoring

2020 ◽  
Vol 19 (1) ◽  
pp. 51-59
Author(s):  
Cameron Ross ◽  
Peter Lambs ◽  
Paul McAlpine ◽  
Gavin Kennedy ◽  
Chris Button
Keyword(s):  
Angular Velocity ◽  
Human Performance ◽  
Angular Displacement ◽  
Science Research ◽  
Performance Outcomes ◽  
Test Reliability ◽  
Validity And Reliability ◽  
Angular Velocity Vector ◽  
Rms Error ◽  
Snow Sports

AbstractWearable sensors that can be used to measure human performance outcomes are becoming increasingly popular within sport science research. Validation of these sensors is vital to ensure accuracy of extracted data. The aim of this study was to establish the validity and reliability of gyroscope sensors contained within three different inertial measurement units (IMU). Three IMUs (OptimEye, I Measure U and Logger A) were fixed to a mechanical calibration device that rotates through known angular velocities and positions. RMS scores for angular displacement, which were calculated from the integrated angular velocity vectors, were 3.85° ± 2.21° and 4.34° ± 2.57° for the OptimEye and IMesU devices, respectively. The RMS error score for the Logger A was 22.76° ± 23.22°, which was attributed to a large baseline shift of the angular velocity vector. After a baseline correction of all three devices, RMS error scores were all below 3.90°. Test re-test reliability of the three gyroscope sensors were high with coefficient of variation (CV%) scores below 2.5%. Overall, the three tested IMUs are suitable for measuring angular displacement of snow sports manoeuvres after baseline corrections have been made. Future studies should investigate the accuracy and reliability of accelerometer and magnetometer sensors contained in each of the IMUs to be used to identify take-off and landing events and the orientation of the athlete at those events.

The social value of Participatory Ergonomics from a practitioner’s perspective

2020 ◽  
Vol 64 (1) ◽  
pp. 919-923
Author(s):  
Kátia M. Costa-Black ◽  
Chris Arteberry
Keyword(s):  
Human Performance ◽  
Well Being ◽  
Participatory Approach ◽  
Performance Outcomes ◽  
Participatory Ergonomics ◽  
Worker Health ◽  
Healthy Working ◽  
The Social ◽  
Health And Well Being ◽  
Total Worker Health

Ergonomics applies a set of ambitious frameworks and robust body of evidence for integrating different practices to optimize worker health and well-being. One recognized framework is the participatory approach, which delves into sociotechnical workplace actions – developed from the ground up – to achieve improved human performance outcomes and acceptability across the organization. Much of what is known about the value of participatory ergonomics centers on return-on-investment analyses related to injury prevention. Outside this spectrum, little has been discussed. This paper imparts how a participatory approach can lead to various positive impacts beyond financial gains, mainly by focusing on continuous improvements at the management systems level and on proactively motivating people and organizations to embrace healthy working conditions and behaviors. Issues such as the social-ethical value of involving workers in work design and return-to-work solutions are discussed to illustrate the holistic value of participatory ergonomics in the context of Total Worker Health.

scholarly journals Are the Assioma Favero Power Meter Pedals a Reliable Tool for Monitoring Cycling Power Output?

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2789
Author(s):  
Víctor Rodríguez-Rielves ◽  
José Ramón Lillo-Beviá ◽  
Ángel Buendía-Romero ◽  
Alejandro Martínez-Cava ◽  
Alejandro Hernández-Belmonte ◽  
...  
Keyword(s):  
Power Output ◽  
Gold Standard ◽  
Cycle Ergometer ◽  
Test Reliability ◽  
Direct Drive ◽  
Validity And Reliability ◽  
Power Meter ◽  
High Workload ◽  
Vibration Stress ◽  
40 Hz

This study aimed to examine the validity and reliability of the recently developed Assioma Favero pedals under laboratory cycling conditions. In total, 12 well-trained male cyclists and triathletes (VO2max = 65.7 ± 8.7 mL·kg−1·min−1) completed five cycling tests including graded exercises tests (GXT) at different cadences (70–100 revolutions per minute, rpm), workloads (100–650 Watts, W), pedaling positions (seated and standing), vibration stress (20–40 Hz), and an 8-s maximal sprint. Tests were completed using a calibrated direct drive indoor trainer for the standing, seated, and vibration GXTs, and a friction belt cycle ergometer for the high-workload step protocol. Power output (PO) and cadence were collected from three different brand, new pedal units against the gold-standard SRM crankset. The three units of the Assioma Favero exhibited very high within-test reliability and an extremely high agreement between 100 and 250 W, compared to the gold standard (Standard Error of Measurement, SEM from 2.3–6.4 W). Greater PO produced a significant underestimating trend (p < 0.05, Effect size, ES ≥ 0.22), with pedals showing systematically lower PO than SRM (1–3%) but producing low bias for all GXT tests and conditions (1.5–7.4 W). Furthermore, vibrations ≥ 30 Hz significantly increased the differences up to 4% (p < 0.05, ES ≥ 0.24), whereas peak and mean PO differed importantly between devices during the sprints (p < 0.03, ES ≥ 0.39). These results demonstrate that the Assioma Favero power meter pedals provide trustworthy PO readings from 100 to 650 W, in either seated or standing positions, with vibrations between 20 and 40 Hz at cadences of 70, 85, and 100 rpm, or even at a free chosen cadence.

Urdu Translation and Validation of Activities-Specific Balance Confidence (ABC) Scale

2021 ◽  
Vol 15 (12) ◽  
pp. 3505-3508
Author(s):  
Noor Ul Ain Fatima ◽  
Qurat-Ul- Ain ◽  
Fareeha Kausar ◽  
Mian Ali Raza ◽  
Misbah Waris ◽  
...  
Keyword(s):  
Older Adults ◽  
Construct Validity ◽  
Correlation Coefficient ◽  
Content Validity ◽  
Assessment Tool ◽  
Test Reliability ◽  
Validity And Reliability ◽  
A Value ◽  
Abc Scale ◽  
Translation And Validation

Objective: To translate and validate the ABC-Scale in Urdu language to predict risk of fall in older population. Study design: Cross-cultural Translation and validation Place and Duration: Study was conducted in older adult community of Sialkot from March 2020 to December 2020. Methodology: Translation of ABC in Urdu was conducted by using Beaton et al guidelines. Two bilingual translators translated the original version into Urdu language step wise, correction process was followed. Then two backward translations were done by language expert. After all this process, the translated version was reviewed by the professionals and the final version was applied on 15 individuals. Its reliability and validity was tested on 60 older adults. Results: For test re test reliability, intra class correlation coefficient ICC was measured with a value of 0.984 Which shows good test re-test reliability. The internal consistency and reliability of ABC was calculated by Cronbach’s alpha for total score with a value of 0.985. Content validity was good with values of CVI ranging from 0.767 to 0.955. To test the discriminative validity, independent t test was used to show the difference between the healthy and unhealthy adults. Factor analysis of UABC showed total variance 81.277 and cumulative variance was also 81.277. To calculate construct validity of U-ABC Pearson’s correlation coefficient was used and measured as 0.558. Conclusion: It was concluded that Urdu version of UABC is a valid assessment tool for older adults with fear of fall. It has good content validity, construct validity and reliability. Keywords: activities specific balance scale, validation, Urdu translation, reliability, tool translation

scholarly journals Stakeholder-Driven Design Evolution of the Leveraged Freedom Chair Developing World Wheelchair

2012 ◽  
Author(s):  
Amos G. Winter ◽  
Mario A. Bollini ◽  
Benjamin M. Judge ◽  
Natasha K. Scolnik ◽  
Harrison F. O’Hanley ◽  
...  
Keyword(s):  
Developing Countries ◽  
Angular Velocity ◽  
East Africa ◽  
Survey Data ◽  
Angular Displacement ◽  
Low Cost ◽  
Center Of Gravity ◽  
Mechanical Advantage ◽  
Design Evolution ◽  
Propulsion Force

The Leveraged Freedom Chair (LFC) is a low-cost, all-terrain, variable mechanical advantage, lever-propelled wheelchair designed for use in developing countries. The user effectively changes gear by shifting his hands along the levers; grasping near the ends increases torque delivered to the drive-train, while grasping near the pivots enables a larger angular displacement with every stroke, which increases angular velocity in the drivetrain and makes the chair go faster. This paper chronicles the design evolution of the LFC through three user trials in East Africa, Guatemala, and India. Feedback from test subjects was used to refine the chair between trials, resulting in a device 9.1 kg (20 lbs) lighter, 8.9 cm (3.5 in) narrower, and with a center of gravity 12.7 cm (5 in) lower than the first iteration. Survey data substantiated increases in performance after successive iterations. Quantitative biomechanical performance data were also measured during the Guatemala and India trials, which showed the LFC to be 76 percent faster and 41 percent more efficient during a common daily commute and able to produce 51 percent higher peak propulsion force compared to conventional, pushrim-propelled wheelchairs.

scholarly journals Validity and Reliability of the Sport Readiness Questionnaire Focused on Musculoskeletal Injuries

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Gianfranco Sganzerla ◽  
Christianne de Faria Coelho Ravagnani ◽  
Silvio Assis de Oliveira-Junior ◽  
Fabricio Cesar de Paula Ravagnani
Keyword(s):  
Internal Consistency ◽  
Affirmative Answer ◽  
Musculoskeletal Injuries ◽  
Test Reliability ◽  
Positive Finding ◽  
Validity And Reliability ◽  
Kappa Index ◽  
Medical Settings ◽  
Future Studies ◽  
Sensitivity Specificity

Background: The pre-participation physical evaluation (PPE), which includes a musculoskeletal system evaluation, identifies factors that may be a risk for athletes while practicing sport. Thus, the Sport Readiness Questionnaire, focused on musculoskeletal injuries (MIR-Q) was developed to screen athletes at risk of future injuries or worsening pre-existing injuries during training or competition. However, the criterion-related validity and reliability of the MIR-Q have not yet been analyzed. Objectives: To test the criterion-related validity and reliability (internal consistency and test-retest) of the MIR-Q. Methods: One hundred and twenty adult athletes from different sports (17 women) completed the MIR-Q and underwent a physical orthopedic examination (POE) performed by an orthopedic physician. At least one affirmative answer on the MIR-Q, as well as one positive finding on the POE, was considered “a risk factor for sport injury”. The validity was assessed from sensitivity, specificity, and accuracy measurements. Internal consistency was obtained through the KR-20 test. Reliability was measured using the test-retest method in a 7-14-day interval with a sub-sample (n = 41) and verified by the Kappa index. Results: Eighty-one (67.5%) questionnaires contained positive responses. The sensitivity of the MIR-Q against POE was high (84.4%), while specificity and accuracy were considered moderate, with values of 42.7% and 58.0%, respectively. Internal consistency was moderate (KR-20 = 0.57), and test-retest was reduced (K = 0.30; P = 0.02). Conclusions: The MIR-Q was associated with high values of validity and low values of reliability. The questionnaire may be an alternative tool for musculoskeletal screening during PPE in limited medical settings (sports OR orthopedic physician) conditions. Future studies should investigate the predictive validity of the MIR-Q, and psychometric properties of the questionnaire with younger athletes.

Effect of Preview on Digital Pursuit Control Performance

1978 ◽  
Vol 20 (3) ◽  
pp. 371-377 ◽  
Author(s):  
Tarald O. Kvålseth
Keyword(s):  
Human Performance ◽  
Autoregressive Process ◽  
Control Task ◽  
Error Performance ◽  
First Order ◽  
Pursuit Control ◽  
Significant Performance ◽  
Rms Error ◽  
Different Characteristics ◽  
Reference Input

The effect of preview on human performance during a digital pursuit control task was analyzed for different preview spans and different characteristics of the reference input. The data from eight subjects revealed that the RMS error performance improved substantially from the case of no preview to that of one preview point, while the use of additional preview points did not result in any further significant performance improvement. The benefit of preview was most clearly established when the reference input was generated by a purely random process as opposed to a first-order autoregressive process (with the parameter α = 0.95). The RMS error increased when the variance of the reference input increased. The error appeared to be normally distributed with a tendency towards a negative bias.

Sensor Placement for Angular Velocity Determination

2005 ◽  
Vol 128 (3) ◽  
pp. 543-547 ◽  
Author(s):  
Guy M. Genin ◽  
Joseph Genin
Keyword(s):  
Angular Velocity ◽  
Rigid Body ◽  
Velocity Vector ◽  
Constraint Equation ◽  
Complete Characterization ◽  
Angular Velocity Vector ◽  
Algebraic Constraint ◽  
Transducer Placement

Velocity transducer placement to uniquely determine the angular velocity of a rigid body is investigated. The angular velocity of a rigid body can be determined with no fewer than five properly placed velocity transducers, if no other types of sensors are present and no algebraic constraint equation involving the angular velocity vector can be written. Complete characterization of the velocity of a rigid body requires six transducers. Choice of transducer placement and orientation requires care, as suboptimal transducer placement can result in data from which the determination of a unique angular velocity vector is impossible. Conditions for successful transducer placement are established, and two examples of adequate transducer placement are presented: an Earth-penetrating projectile, and a bioengineering device for the measurement of head motion.

The Dynamics of a Gyroscope Supported by a Flexible Circular Plate

1982 ◽  
Vol 49 (3) ◽  
pp. 601-605 ◽  
Author(s):  
J. S. Burdess
Keyword(s):  
Angular Velocity ◽  
Circular Plate ◽  
Angular Displacement ◽  
Performance Characteristics ◽  
Free Motion ◽  
Rigid Rotor ◽  
Modes Of Operation ◽  
Constant Rate ◽  
Flexible Circular Plate

The dynamics of a rigid rotor supported on a flexible circular plate is investigated and it is shown that the arrangement is capable of operating as a tuned free rotor gyroscope. The performance characteristics of the gyroscope are evaluated and the analysis shows that the steady displacment of the rotor may be used to measure either the angular velocity or angular displacement of the supporting casing. For both modes of operation the free motion and the response to a constant rate and a vibratory input is determined.

An inertial piezoelectric hybrid actuator with large angular velocity and high resolution

2019 ◽  
Vol 30 (14) ◽  
pp. 2099-2111 ◽  
Author(s):  
Huilu Bao ◽  
Jianming Wen ◽  
Kang Chen ◽  
Jijie Ma ◽  
Dan Lei ◽  
...  
Keyword(s):  
High Resolution ◽  
Angular Velocity ◽  
Natural Frequencies ◽  
Angular Displacement ◽  
High Accuracy ◽  
Laser Vibrometer ◽  
Type B ◽  
First Order ◽  
Offset Distance ◽  
Hybrid Actuator

This article proposes an inertial piezoelectric actuator with hybrid design of asymmetrically clamping structures and a bias unit for the achievement of large angular velocity and high resolution. To investigate the influence of asymmetrical clamp and bias unit on the driving performance, two types of actuators were fabricated and tested. Combined effects from asymmetrical clamp and bias unit contribute to type A, while their subtractive effect is applied to type B. Using a scanning laser vibrometer, experiments were conducted to analyze the characteristics of the angular displacement and corresponding velocity. It is indicated that the measured first-order natural frequencies for above two types are 13.828 and 14.141 Hz, which agrees well with the simulation results of 16.666 and 17.379 Hz, respectively. Besides, compared with the actuators with simple asymmetrical clamping structure or bias unit, this hybrid actuator can obtain an angular velocity 6.87 rad/s at 80 V and 16 Hz and a resolution of 2.80 μrad under a square signal of 20 V and 1 Hz and an offset distance of −22 mm. As a result, the proposed actuators can achieve large angular velocity and high resolution, which is potentially applicable to quick positioning with high accuracy.

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