scholarly journals A Novel Accelerometry-Based Metric to Improve Estimation of Whole-Body Mechanical Load

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3398
Author(s):  
Enzo Hollville ◽  
Antoine Couturier ◽  
Gaël Guilhem ◽  
Giuseppe Rabita
Keyword(s):  
Standard Error ◽  
Concurrent Validity ◽  
Mechanical Load ◽  
Whole Body ◽  
Theoretical Issue ◽  
Physical Demand ◽  
Sport Training ◽  
Lower Back ◽  
In Series ◽  
Wearable Accelerometers

While the Player Load is a widely-used parameter for physical demand quantification using wearable accelerometers, its calculation is subjected to potential errors related to rotational changes of the reference frame. The aims of this study were (i) to assess the concurrent validity of accelerometry-based Player Load against force plates; (ii) to validate a novel metric, the Accel’Rate overcoming this theoretical issue. Twenty-one recreational athlete males instrumented with two triaxial accelerometers positioned at the upper and lower back performed running-based locomotor movements at low and high intensity over six in-series force plates. We examined the validity of the Player Load and the Accel’Rate by using force plates. Standard error of the estimate was small to moderate for all tested conditions (Player Load: 0.45 to 0.87; Accel’Rate: 0.25 to 0.95). Accel’Rate displayed trivial to small mean biases (−1.0 to 6.1 a.u.) while the Player Load displayed systematic very large to extremely large mean biases (17.1 to 226.0 a.u.). These findings demonstrate a better concurrent validity of the Accel’Rate compared to the Player Load. This metric could be used to improve the estimation of whole-body mechanical load, easily accessible in sport training and competition settings.

scholarly journals Preventive action with a population of excavator drivers exposed to whole-body vibration

Work ◽  
2021 ◽  
Vol 68 (2) ◽  
pp. 473-481
Author(s):  
P. Bossi ◽  
P. Meert
Keyword(s):  
Back Pain ◽  
Lower Back Pain ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Preventive Action ◽  
Body Vibration ◽  
Lower Back ◽  
Work Tasks ◽  
Determining Factors ◽  
Exposure Levels

BACKGROUND: Whole-body vibration is a major cause of lower back pain among employees, and the medical and preventive care teams of occupational health departments are often confronted with lower back pain problems among machine operators. OBJECTIVES: The objectives of this research are to determine the number of excavator drivers exposed to whole-body vibration levels above 0.5m/s2, identify other exposure factors that may contribute to back pain, and propose corrective measures. METHODS: Vibration measurements were carried out on individual excavator drivers while they were observed carrying out working tasks, after which prevention advice is given. Factors which determine vibration levels are logged on to a database. RESULTS: The multivariate analysis of several determining factors shows vibration exposure levels vary depending on the varied work tasks being carried out. CONCLUSION: This study identifies exposed employees among excavator operators. For each workstation, the determining factors that could explain the high exposures to vibrations are identified. This work shows the important role of tasks on exposure levels. A better adaptation of the tools used to carry out work tasks would allow a decrease in the vibration level of this type of machine.

scholarly journals Effects of a Wearable Carriage Aid on Whole-Body Physiological Measures and Balance

2020 ◽  
Vol 10 (22) ◽  
pp. 8076
Author(s):  
Saad A. Alabdulkarim ◽  
Abdulsalam M. Farhan ◽  
Mohamed Z. Ramadan
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Minute Ventilation ◽  
Aid Effectiveness ◽  
Whole Body ◽  
Physiological Measures ◽  
Future Studies ◽  
Lower Back ◽  
The Impact ◽  
Load Mass

Carriage tasks are common and can lead to shoulder and lower back injuries. Wearable carriage aids have shown mixed effects on local physical demand measures. This study examined the impact of a wearable carriage aid on whole-body physiological measures (normalized oxygen consumption, minute ventilation, respiratory rate, and heart rate) to obtain a more comprehensive assessment regarding aid effectiveness. Additionally, this study investigated the effect of wearing the device on perceived balance. The potential moderating effect of carried load mass was considered. The examination was conducted while walking on a treadmill at a constant speed (2 km/h) for 5 min and was completed by 16 participants. Wearing the device reduced normalized oxygen consumption (~14%), minute ventilation (~7%), and heart rate (~3%), while substantially improving perceived balance (~61%). These effects were consistent across examined carried load levels. Although this study highlighted the potential for the developed aid, future studies are required for more diverse and realistic testing conditions.

scholarly journals Body fat does not affect venous bubble formation after air dives of moderate severity: theory and experiment

2013 ◽  
Vol 114 (5) ◽  
pp. 602-610 ◽  
Author(s):  
Nico A. M. Schellart ◽  
Tjeerd P. van Rees Vellinga ◽  
Rob A. van Hulst
Keyword(s):  
Body Fat ◽  
Decompression Sickness ◽  
Bubble Formation ◽  
Maximal Oxygen Consumption ◽  
Whole Body ◽  
Small Range ◽  
Gas Embolism ◽  
Blood Compartment ◽  
In Series ◽  
Venous Gas Embolism

For over a century, studies on body fat (BF) in decompression sickness and venous gas embolism of divers have been inconsistent. A major problem is that age, BF, and maximal oxygen consumption (V̇o2max) show high multicollinearity. Using the Bühlmann model with eight parallel compartments, preceded by a blood compartment in series, nitrogen tensions and loads were calculated with a 40 min/3.1 bar (absolute) profile. Compared with Haldanian models, the new model showed a substantial delay in N2 uptake and (especially) release. One hour after surfacing, an increase of 14–28% in BF resulted in a whole body increase of the N2 load of 51%, but in only 15% in the blood compartment. This would result in an increase in the bubble grade of only 0.01 Kisman-Masurel (KM) units at the scale near KM = I−. This outcome was tested indirectly by a dry dive simulation (air breathing) with 53 male divers with a small range in age and V̇o2max to suppress multicollinearity. BF was determined with the four-skinfold method. Precordial Doppler bubble grades determined at 40, 80, 120, and 160 min after surfacing were used to calculate the Kisman Integrated Severity Score and were also transformed to the logarithm of the number of bubbles/cm2 (logB). The highest of the four scores yielded logB = −1.78, equivalent to KM = I−. All statistical outcomes of partial correlations with BF were nonsignificant. These results support the model outcomes. Although this and our previous study suggest that BF does not influence venous gas embolism (Schellart NAM, van Rees Vellinga TP, van Dijk FH, Sterk W. Aviat Space Environ Med 83: 951–957, 2012), more studies with different profiles under various conditions are needed to establish whether BF remains (together with age and V̇o2max) a basic physical characteristic or will become less important for the medical examination and for risk assessment.

Estimation of changes of lower limbs reactivity among mountain cyclist under the influence of sauna treatment - abstract

2016 ◽  
Vol 24 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Paweł Niewiadomy ◽  
Joanna Tiffert-Tłok ◽  
Katarzyna Szuścik ◽  
Anna Stolecka-Warzecha ◽  
Krystyna Kwaśna
Keyword(s):  
Analysis Of Variance ◽  
Research Method ◽  
Age Groups ◽  
Lower Limbs ◽  
Whole Body ◽  
Training Process ◽  
Rehabilitation Training ◽  
Sport Training ◽  
Human Ability ◽  
Two Age Groups

Abstract Background: Elaborated system of neuromuscular connections gives to a human ability of body control, possibility to move and perform any complicated moves. The issue of neuromuscular conduction appears more frequently in physiotherapy, biological restoration or, widely perceived, sport training. Physiotherapists often wonder how sauna treatment, mainly used in biological restoration, influence on changes of its conduction and, on which level of a rehabilitation, training process or biological restoration should it be used. The aim of this paper was to check how an organism would react after methodically conducted sauna treatments in a form of whole body biological restoration. Material/Methods: Competitors of cycling group GR AIRCO Team participated in research. Twelve men were classified and divided onto two age groups. On the basis of questionnaires personal details as well as basic antropometric parameters were collected. Tool used to measure reactivity was chosen to research method: Reactivity Measure MCZR/ATB 1.0. Results: Analysis of variance of following measurements did not show any statistically crucial differences between the group under the age of 30 and over 30 (p>0,05). Results are shown respectively for right leg, left leg, both lower limbs tested simultaneously with the division onto age groups. Analysis of variance show increase of reactivity for all tested participants after sauna. Conclusions: Sauna treatment among cyclist has impact on a rate of lower limbs reactivity tested simultaneously with impulse differentiation to an appropriate legs.

scholarly journals Validity and Reliability of the Standardized Orthopedic Assessment Tool (SOAT): A Variation of the Traditional Objective Structured Clinical Examination

2014 ◽  
Vol 49 (3) ◽  
pp. 373-380 ◽  
Author(s):  
Mark R. Lafave ◽  
Larry Katz
Keyword(s):  
Correlation Coefficient ◽  
Standard Error ◽  
Clinical Competence ◽  
Concurrent Validity ◽  
Assessment Tool ◽  
Global Rating ◽  
Validity And Reliability ◽  
Pearson Product Moment Correlation ◽  
Standard Error Of Measurement ◽  
Error Of Measurement

Context: Health care professions have replaced traditional multiple choice tests or essays with structured and practical, performance-based examinations with the hope of eliminating rater bias and measuring clinical competence. Objective: To establish the validity and reliability of the Standardized Orthopedic Assessment Tool (SOAT) as a measure of clinical competence of orthopaedic injury evaluation. Design: Descriptive laboratory study. Setting: University. Patients or Other Participants: A total of 60 undergraduate students and 11 raters from 3 Canadian universities and 1 standardized patient. Intervention(s): Students were required to complete a 30-minute musculoskeletal evaluation in 1 of 2 randomly assigned mock scenarios involving the knee (second-degree medial collateral ligament sprain) or the shoulder (third-degree supraspinatus muscle strain). Main Outcome Measure(s): We measured interreliability with an intraclass correlation coefficient (ICC) (2,k) and stability of the tool with standard error of measurement and confidence intervals. Agreement was measured using Bland-Altman plots. Concurrent validity was measured using a Pearson product moment correlation coefficient whereby the raters' global rating of a student was matched to the cumulative mean grade score. Results: The ICCs were 0.75 and 0.82 for the shoulder and knee cases, respectively. Bland-Altman plots indicated no systematic bias between raters. In addition, Pearson product moment correlation analysis demonstrated a strong relationship between the overall cumulative mean grade score and the global rating score of the examinees' performances. Conclusions: This study demonstrated good interrater reliability of the SOAT with a standard error of measurement that indicated very modest stability, strong agreement between raters, and correlation indicative of concurrent validity.

scholarly journals The Relationship Between Whole-Body External Loading and Body-Worn Accelerometry During Team-Sport Movements

2017 ◽  
Vol 12 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Niels J. Nedergaard ◽  
Mark A. Robinson ◽  
Elena Eusterwiemann ◽  
Barry Drust ◽  
Paulo J. Lisboa ◽  
...  
Keyword(s):  
Loading Rate ◽  
Mechanical Load ◽  
Statistical Parametric Mapping ◽  
Team Sport ◽  
Whole Body ◽  
External Loading ◽  
Ground Contact ◽  
Peak Acceleration ◽  
Contact Phase ◽  
The Relationship

Purpose:To investigate the relationship between whole-body accelerations and body-worn accelerometry during team-sport movements.Methods:Twenty male team-sport players performed forward running and anticipated 45° and 90° side-cuts at approach speeds of 2, 3, 4, and 5 m/s. Whole-body center-of-mass (CoM) accelerations were determined from ground-reaction forces collected from 1 foot–ground contact, and segmental accelerations were measured from a commercial GPS accelerometer unit on the upper trunk. Three higher-specification accelerometers were also positioned on the GPS unit, the dorsal aspect of the pelvis, and the shaft of the tibia. Associations between mechanical load variables (peak acceleration, loading rate, and impulse) calculated from both CoM accelerations and segmental accelerations were explored using regression analysis. In addition, 1-dimensional statistical parametric mapping (SPM) was used to explore the relationships between peak segmental accelerations and CoM-acceleration profiles during the whole foot–ground contact.Results:A weak relationship was observed for the investigated mechanical load variables regardless of accelerometer location and task (R2 values across accelerometer locations and tasks: peak acceleration .08–.55, loading rate .27–.59, and impulse .02–.59). Segmental accelerations generally overestimated whole-body mechanical load. SPM analysis showed that peak segmental accelerations were mostly related to CoM accelerations during the first 40–50% of contact phase.Conclusions:While body-worn accelerometry correlates to whole-body loading in team-sport movements and can reveal useful estimates concerning loading, these correlations are not strong. Body-worn accelerometry should therefore be used with caution to monitor whole-body mechanical loading in the field.

Characterization of the Frequency and Muscle Response in the Lumbar and Thoracic Spines During Sinusoidal Vertical Whole Body Vibration

2013 ◽  
Author(s):  
Hassam A. Baig ◽  
Daniel B. Dorman ◽  
Bethany L. Shivers ◽  
Arlene Breaux-Waltz ◽  
V. Carol Chancey ◽  
...  
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Low Back ◽  
Muscle Response ◽  
Body Vibration ◽  
Lower Back ◽  
The Relationship

Vibration exposure has been linked to chronic neck and lower back pain [1,2]. For example, American male workers operating vibrating vehicles, such as industrial trucks and tractors, have been reported to have a higher prevalence of low back pain than workers whose occupations do not involve vibration exposures [1]. Also, military helicopter aviators report increased pain during deployment compared to pre-deployment, with between 22–37% reporting neck and 39–70% reporting low back pain [2]. It has been suggested that the cyclic muscle response to whole body vibration (WBV) can lead to muscle fatigue, further contributing to the development of low back pain [3]. Although several studies have measured the transmissibility response of the human spine [4,5], studies defining the mechanical effects of whole body vibration in a seated human are limited [4,5] and none have investigated the relationship between the biomechanical and muscle activity responses during such whole body vibration exposures.

Reliability and Concurrent Validity of the Test of Motor Impairment-Henderson Revision

1990 ◽  
Vol 7 (3) ◽  
pp. 249-258 ◽  
Author(s):  
Katherine J. Riggen ◽  
Dale A. Ulrich ◽  
John C. Ozmun
Keyword(s):  
Standard Error ◽  
Concurrent Validity ◽  
Test Score ◽  
Short Form ◽  
Motor Impairment ◽  
Final Test ◽  
Motor Proficiency ◽  
Standard Error Of Measurement ◽  
Absolute Reliability ◽  
Error Of Measurement

The reliability and concurrent validity of the Test of Motor Impairment-Henderson Revision was evaluated employing a sample of preschoolers. Absolute reliability of the final test score was established by calculating the standard error of measurement (SEM). An SEM of .86 was obtained. The consistency of decisions related to motor impairment or nonimpairment was estimated by calculating the proportion of agreement index across two testing occasions and Kappa. A 90% agreement was obtained with Kappa equal to .71. Concurrent validity using the Bruininks-Oseretsky Test of Motor Proficiency-Short Form as the criterion resulted in an 88% agreement between the two tests.

Concurrent Rupture of Two Molecular Bonds in Series: Implications for Dynamic Force Spectroscopy

2017 ◽  
Vol 84 (11) ◽  
Author(s):  
Ji Lin ◽  
Yuan Lin ◽  
Jin Qian
Keyword(s):  
Diffusion Processes ◽  
Force Spectroscopy ◽  
Solid Surfaces ◽  
Theoretical Issue ◽  
Dynamic Force ◽  
Dissociation Kinetics ◽  
Dynamic Force Spectroscopy ◽  
Receptor Ligand ◽  
Mechanical Coupling ◽  
In Series

The immobilization of receptor–ligand molecules in dynamic force spectroscopy (DFS) often relies on an extra noncovalent linkage to solid surfaces, resulting in two barrier-crossing diffusion processes in series and concurrent bond dissociations. One outstanding theoretical issue is whether the linkage between the immobilizer and biomolecule is sufficiently strong during repeated force ramping in the measurements and how it might influence the interpretation on receptor–ligand kinetics. Following the classical framework by Kramers, we regard each dissociation process as a flux of probabilistic bond configuration outward over an energy barrier in the coordinated energy landscape, and solve the two coupled boundary value problems in the form of Smoluchowski equation. Strong kinetic and mechanical coupling is observed between the two molecular bonds in series, with the results showing that involving a noncovalent linkage in DFS can obscure the unbinding characteristics of the receptor–ligand bond. Our approach provides a quantitative assessment to the hidden effects of having a fragile molecular anchorage in DFS and allows the corrected interpretation on receptor–ligand dissociation kinetics in the case.

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