Improved Animal Model for Vibration Injury Study

Hand-Arm Vibration Syndrome is a debilitating condition that affects millions of power-tool users in the  U.S. Research into its etiology has been hampered by deficiencies in animal models used for vibration studies.  Our objective was to design an animal vibration injury model that: 1) vibrates only the studied limb, not  the body; and 2) avoids anaesthesia, thus allowing purer focus on physiological effects of vibration while  reducing pain and distress for the animals, thereby enhancing their well-being. We compared advantages  and disadvantages of several models, studying body temperature, body weight, tissue perfusion, vascular  pathohistology, and general animal condition. Our model uses an apparatus that limits vibration to one  body part and a specially designed cage that minimizes animal stress and suffering, eliminating the need for  anaesthesia. It is ideal for the study of vibration injury, providing tissue damaged purely by vibration that  can be used for pathohistology and biochemical study.

Investigation of the Dynamic Interaction between the Human Body and Car Seat Using a Unique Simulation Technique

Numerical simulations and mathematical models have been developed over last many years on the certain portions of human body, car seat or automobile to characterise, monitor and assess the level of vibration and its effects on the human occupant inside the automotive. Though, the numerical simulations can define the level and nature of vibration and its transmissibility up to a certain stage, vibration measurement techniques have also been gaining importance for last several years to fill the limitations of the theoretical models. Efforts have also been made to carry out vibration related investigations using combined numerical simulation and measurement procedure for the car seat and the seated human body inside car, though the numbers of case studies carried out with the combination of simulation and measurement procedure are very less. Some technologies have been achieved to judge the level of vibration inside the car seat and its human occupant, though those technologies cover only effects of vibration, dynamics or measurement techniques on specific portions of the car or the human body without considering all the real life factors, e.g., human gender, shape of the human portions, size specific stiffness properties, in-vehicle operating conditions and damping factors. Approaches to provide a comprehensive solution to estimate the level of vibration without real life testing have not been carried out by the existing technologies very well. More than that the existing technologies investigate only particular modules of the entire human-car dynamic systems, e.g., a specific human part, seat and human interaction, vibration transmission from seat to human body or the vibration measurement technique. So, there is enormous scope of further improvement and the aim of this research work is to provide a unique simulated system considering all the critical real life factors. Outcome of this simulation study will evaluate the vibration levels inside the segments of seated human body inside a car and car seat omitting the necessity of real-life practical testing and provide the solution by linking module-wise investigations of human body and car seat. Initiative has been taken to fill up the gaps in the existing technologies and offer a novel study on the comprehensive simulation model of the combined human body and car seat bio-dynamic system to optimize the health, safety and comfort levels of the car seated human body. Present research work covered the tasks of establishing the simulations for non-linear bio-dynamic model of the seated human body, feasibility and behaviour inspection of polyurethane foam cushions, contact mechanism assignment between the human body and the car seat and establishing the simulation of car seated human occupant under the real life environment. Vertical displacements, vertical accelerations and frequencies at designated points of human body and car seat have been extracted from the simulation outcome and the obtained results have been validated though real-life vibration testing data. This unique simulation methodology can successfully be implemented to predict the final vibration levels inside the car seat and the car seated human body to optimize the health, safety and comfort of the human-car seat system. The outlined novel technique contributed knowledge to the entire human body and car seat dynamic system rather than focusing only on a very specific portion of the system. An industrial guideline has been presented to implement this unique simulation methodology in similar sectors, which will lead various industries to avoid time consuming and expensive bio-dynamic vibration testing methods and help to understand the impact of vibration on the in-vehicle human body in a better way

Evaluation of Man-Made Ground Vibrations

The evaluation method of the man-made ground vibration and its formula are reviewed in the paper. The author\u27s formula presented the possibility to solve the Vibration in near source due to the body wave from varied sources. The ground Vibration sources, such as traffic, pile driving etc. and the effects of the embedded source are involved as well. The parameters of the soil energy attenuation and the geometrical attenuation presented have been examined by National Standard Committee of CHINA in 1994. The case histories on varied testing site and vibrating effects are described

Small and inconsistent effects of whole body vibration on athletic performance:a systematic review and meta-analysis

We quantified the acute and chronic effects of whole body vibration on athletic performance or its proxy measures in competitive and/or elite athletes. Systematic literature review and meta-analysis. Whole body vibration combined with exercise had an overall 0.3 % acute effect on maximal voluntary leg force (-6.4 %, effect size = -0.43, 1 study), leg power (4.7 %, weighted mean effect size = 0.30, 6 studies), flexibility (4.6 %, effect size = -0.12 to 0.22, 2 studies), and athletic performance (-1.9 %, weighted mean effect size = 0.26, 6 studies) in 191 (103 male, 88 female) athletes representing eight sports (overall effect size = 0.28). Whole body vibration combined with exercise had an overall 10.2 % chronic effect on maximal voluntary leg force (14.6 %, weighted mean effect size = 0.44, 5 studies), leg power (10.7 %, weighted mean effect size = 0.42, 9 studies), flexibility (16.5 %, effect size = 0.57 to 0.61, 2 studies), and athletic performance (-1.2 %, weighted mean effect size = 0.45, 5 studies) in 437 (169 male, 268 female) athletes (overall effect size = 0.44). Whole body vibration has small and inconsistent acute and chronic effects on athletic performance in competitive and/or elite athletes. These findings lead to the hypothesis that neuromuscular adaptive processes following whole body vibration are not specific enough to enhance athletic performance. Thus, other types of exercise programs (e.g., resistance training) are recommended if the goal is to improve athletic performance

Modeling Predictors of Whole Body Vibration Exposure among Saskatchewan Farmers: a Key Step in Low Back Disorder Prevention

Background Farmers experience a high rate of low back pain (LBP), with a lifetime prevalence of up to 75%. Whole body vibration exposure has been recognized as a significant physical risk factor associated with LBP. The agriculture sector has high whole body vibration exposures related to various machine types; however, little research has assessed vibration exposure in farming due to the inconvenience and cost of direct data collection. Prediction modelling is potentially a cost-efficient way to estimate directly measured exposure. Objectives The objectives of this study are to 1) measure the physical exposure of whole body vibration in Saskatchewan farmers and understand its magnitude and variability between farm machinery; and 2) use farm, vehicle, and task characteristics to determine any predictive relationship with directly-measured whole body vibration exposures among Saskatchewan farmers. Methods A 1-year field study with 3 repeated farm visits was conducted for whole body vibration measurements on 21 farms within a 400 km distance of Saskatoon. Whole body vibration was assessed using a tri-axial accelerometer embedded in a standard rubber seat pad according to international standards (ISO 2631-1). Whole body vibration data were summarized by machinery type into standardized metrics of root-mean-squared accelerations (RMS), peak, crest factor, and vibration dose value (VDV). Vehicle characteristics were gathered by on-site observations supplemented by open access vehicle descriptions through manufacturers. Farm characteristics and farmer’s self-reported whole body vibration exposure were collected via questionnaires. A manually stepwise method was conducted to build mixed-effects models for both RMS and VDV outcomes. Results A total of 87 whole body vibration measurements were gathered from 8 machine types: tractor, combine, pickup truck, grain truck, sprayer, swather, all-terrain vehicle, and skid steer. The average measurement duration was 85 minutes. The mean vector sums were RMS 0.78 m/s², peak 19.34 m/s², crest factor 27.64, and VDV 10.02 m/s1.75. The fixed effects of ‘horsepower’, ‘vehicle transmission type’, ‘farm size’, and ‘farm commodity’ explained 44% of the variance in RMS; while ‘horsepower’, ‘seat suspension type’, ‘loading frequency’, ‘tire tread type’, ‘jerk/jolt frequency’, ‘seat bottom-out frequency’, ‘farm commodity’, and ‘farm size’ explained only 20% of VDV variance. Conclusion High mechanical vibration and shocks from a range vehicle types call for action to reduce agricultural whole body vibration. Although VDV is relatively difficult to predict through farm and vehicle features collected in the present study, RMS can be predicted to a moderately useful degree. Predictors identified via modeling can help explain the variances of whole body vibration exposures and may also serve as new surrogates for future whole body vibration exposure assessment

Development and Assessment of a Virtual Reality Forklift Simulator as a Research Tool to Study Whole-Body Vibration

Operators of forklifts and other heavy machinery are exposed to whole-body vibration as a result of their daily work routine. Lower-back pain and other health risks have been linked to whole-body vibration exposure. A virtual reality simulator has been developed as a tool to study the effects of whole-body vibration and other risk factors associated with forklift operation. This study aims to demonstrate that the vibration exposure during simulation can be adjusted, and to compare the chassis accelerations to those of a real forklift. A sensitivity analysis examined three key parameters to determine their effect on the vibration properties of the simulator chassis. A comparison of field chassis accelerations during a standard work task revealed that the simulator better replicated accelerations for events involving transient surface irregularities, but the simulator had smaller vibrations when traveling across the relatively smooth warehouse floor. The simulator in its current state is a functional tool for evaluating the ergonomics of forklifts; however, further adjustment is required before the system can be considered a viable platform for whole-body vibration research

The Effects of Whole-Body Vibration Training on Trunk Muscle Strength: A Narrative Review

Mechanical vibration can improve neuromuscular function through postural control strategies, muscle tonic mechanisms, and tonic vibration reflexes. Whole body vibration (WBV) has also been announced to increase bone mineral density, muscle endurance and strength, as well as to enhance proprioceptive system. Moreover, WBV training was found to be a constructive strategy for improving the physical performance of elite athletes and healthy individuals in terms of muscle strength, agility, flexibility, and vertical jump height. Although there is still no consensus in research in this area, it is argued that certain molecular mechanisms involved in the physiological adaptations of exercise also emerge during WBV training. Clarifying these physiological mechanisms is crucial for optimizing the effectiveness of WBV trainings. Previous studies have examined the effects of WBV and have indicated developments in muscle strength, muscle endurance, flexibility, muscle cross sectional area, bone mineral density and body composition. However, no standard prescription has been established to optimize the effects of WBV, including the determination of vibration frequency and amplitude. In addition, the majority of previous studies have investigated the effects of WBV training on the extremities. There are few publications investigating its effectiveness on trunk and core muscle strength, which is one of the important indicators of athletic performance. Therefore, we conducted a narrative review of the literature, referring to the Cochrane Library and Medline databases, to summarize the most recent scientific evidence on the effects of whole-body vibration on trunk muscle strength. This narrative review concludes that at least 8 weeks of WBV training is more effective on trunk muscle strength than those performing the same exercises without WBV

Kokovartalonvibraatiohoito Cp-vammaisen lapsen fysioterapiassa

Vibraatiohoito ja sen vaikutukset ovat melko vähän tutkittu hoitomuoto fysioterapiassa. Erityisesti lapsipotilaiden kanssa tämän harjoittelumuodon käyttö on harvinaista. Jatkuvasti määrältään kasvava tutkimusnäyttö vibraatiohoidon positiivisista vaikutuksista antaa näyttöä, että vibraatiohoitoa kannattaa tutkia lisää. (Rauch 2009; Sandström ym. 2005.) Tämä opinnäytetyö on integroitu kirjallisuuskatsaus. Opinnäytetyön tarkoituksena on kerätä uutta tietoa vibraatiohoidon käytöstä osana Cp-lasten fysioterapiaa. Opinnäytetyössä käsitellään Cp-vamman, lapsen toimintakyvyn sekä vibraatiohoidon välisiä yhteyksiä aihetta tutkivan tutkimuksen pohjalta. Tämän työ on tehty yhteistyössä HUS Lastenlinnan kanssa Aineisto kerättiin PubMED:n, PEDro:n sekä EBSCO:n tietokantoja käyttäen tarkkaan määritettyjen hakusanojen avulla hylkäyskriteerejä noudattaen. Lopullinen tulos oli 14 tutkimusta aiheesta. Tutkimusten analyysi tapahtui kvalitatiivisen sisällönanalyysin metodeja noudattaen. Tutkimuksissa oli käytetty monia eri metodeja vaikutusten mittaamiseen ja näiden tulosten ja oman johtopäätösten välisen synteesin luominen tapahtui aiheeseen laajalti perehtymällä sekä aineiston tarkalla analyysilla että tulkinnalla. Tämä työ tarkasteli vibraatiohoidon vaikutusta toimintakykyyn toiminnallisen liikkumisen, kävely, spastisiteetin sekä tasapainon kautta. Tutkimusten tulosten perusteella vibraatiohoito vaikuttaa kaikkiin edellä mainittuihin fyysisen toimintakyvyn osa-alueisiin positiivisesti. Tämä opinnäytetyö koostaa nämä tulokset, kerää uutta tietoa vibraatiohoidon käytöstä Cp-vammaisten lasten fysioterapiassa sekä tarjoaa monia uusia näkökulmia vibraatiohoidon vaikutukksiin sekä soveltuvuuteen Cp-vammaisten lasten terapiaan. Asiasanat: Kokovartalovibraatio, lapset, Cp-vamma, toimintakykyVibration therapy is a fairly little studied treatment method in physical therapy. Especially in the case of children, the application of vibration in therapy or training is very rare. However, the growing number of studies in vibration therapy suggests positive effects and contributes to the need of further studies. (Rauch 2009; Sandström ym. 2005.) This thesis was an integrative literature review. The purpose of this study was to gather new information on the use of whole body vibration in children’s physical therapy. This thesis studies the relations between cerebral palsy (CP), functional performance and vibration therapy through studies on the subject. The thesis was conducted in co-operation with HUS Children’s Castle hospital. The studies used in this thesis were acquired through PubMED, PEDro and EBSCO databases with the use of carefully chosen terms and conditions. The final sample consisted of 14 studies. The analysis of these studies was performed by using qualitative content analysis. The reviewed studies had used a variety of methods to measure the effects of whole body vibration. The synthesis between the results in the studies and the conclusions in this thesis was conducted by thorough study, analysis and interpretation of the studies in use. This thesis focused on the effects of whole body vibration on performance through functional mobility, walking ability, spasticity and balance. The findings suggest that whole body vibration has a positive effect on all the above-mentioned characteristics of functional performance. This thesis collates these results, provides new information and presents several new points of view towards the effects of vibration therapy, its use and suitability in the therapy of children with CP. Keywords: whole body vibration, cerebral palsy, children, functional performanc

Characterization of whole-body vibration for monorail passenger ride comfort

Train travel has always been a major mode of public transport in developed countries. In the inner cities monorails are often used, which are operated at elevated rail or beam, the main advantage being traffic interactions can be minimized while maintaining its original landscape. Ride comfort is the basic requirement for every passenger in all kind of public transports. In monorail, vibration is considered as major factor of discomfort, it transmitted to human body, which contribute many health issues. The aim of this study was to evaluate the whole-body vibration transmission and the effects to the monorail passengers. There were total of twenty-four experiments conducted in a two-car train monorail on its complete line from Kuala Lumpur Sentral to Titiwangsa stations. Human vibration meter (HVM-100) with tri-axial accelerometer pad was used to measure the WBV of passengers and International Standards Organization (ISO) 2631-1: 1997 was used for analysis. The experimental results show that the daily vibration exposure 0.81 m/s2 was higher than the action value 0.5 m/s2 of the standard during peak operation and 0.82 m/s2 during off-peak operation. The health effect was measured 9.90 m/s1.75 during peak operation and 9.94 m/s1.75 during off-peak operation; both values are observed in moderate health effect zone as per standard (8.5 m/s1.75 to 17 m/s1.75). Moreover, the passenger ride comfort was measured, it was found to be fairly-uncomfortable at rear bogie and not-uncomfortable at center of car. The statistical analysis has proven the significance of orientation, location and operating hours by significant value p = 0.000 (i.e. p < α) with 29.5% of the variance has been accounted between groups. This provides justification to standardization of proper priority seating zone. The findings of this study can assist in the standard specification for seating design of monorail. The statistical analysis shows that all results are statistically significant for orientations, locations as well as operations

Modelling of 4WD vehicle driveability during tip-in/tip-out events

This paper describes a modelling method to investigate the dynamic behaviour of 4WD vehicle under a severe driving condition, where the driver applies a rapid tip-in on the accelerator pedal in 2nd gear to achieve maximum engine torque. This is followed by a tip-out event by releasing the accelerator quickly. The Tip-In/Tip-Out events are one of important elements to assess the vehicle driveability. During these test events, the vehicle is expected to generate low frequency vibration between 2 Hz and 10 Hz and gives discomfort feelings induced by resonance effects on sensitive human organs. The aim of this paper is to develop a 4WD vehicle model in a modern object-oriented multi-body simulation tool and study its driveability