Risk Of Repetitive Strain Injury Research Articles

Prevalence of vertical movement asymmetries at trot in Standardbred and Swedish Warmblood foals.

Many horses, just before and during their athletic career, show vertical movement asymmetries, to the same degree as clinically lame horses. It is unknown whether these asymmetries are caused by pain or have alternative explanations, such as inherent biological variation. In the latter case, movement asymmetries would be expected to be present at a very young age. This study aimed to investigate the prevalence of movement asymmetries in foals. Motion analysis, using an inertial measurement unit-based system (Equinosis), was performed on 54 foals (31 Swedish Warmbloods, 23 Standardbreds) during straight-line trot. The foals were between 4-13 weeks old and considered sound by their owners. Differences between the vertical minimum and maximum values recorded for the head (HDmin, HDmax) and pelvis (PDmin, PDmax) between left and right stance were calculated for each stride and an average was computed for each trial. Thresholds for asymmetry were defined as absolute trial mean >6 mm for HDmin and HDmax, and >3 mm for PDmin and PDmax. These thresholds were exceeded for one or several parameters by 83% of Standardbred foals and 45% of Swedish Warmblood foals, demonstrating surprisingly high prevalence of asymmetries in young foals, although the risk of repetitive strain injuries and cumulative risk of trauma injuries was expected to be low in this age group. Standardbred foals showed similar prevalence of asymmetries to that reported previously for yearling Standardbred trotters, so relatively higher prevalence of movement asymmetries may be expected among trotters as a breed. In general, vertical head and pelvic movement asymmetries can be anticipated among foals considered sound by their owners. A better understanding of the aetiology of asymmetries is needed for correct interpretation of objective symmetry measurements in different populations of horses.

PRELIMINARY REVIEW OF MULTISCALE FRET AS INNOVATION OF ERGONOMIC GUITAR

The development of multiscale fret as innovation of ergonomic guitar concept aims to make this innovation applied more by guitar luthiers in designing a guitar signature that is modern and ergonomic. This concept has its own advantages, not only producing specific and organic tones, but also has benefits that can minimize the risk of repetitive strain injuries that are often experienced by guitar players. Therefore, multiscale fret has begun to be widely developed and has become one of the alternative innovations that can be applied by guitar luthiers that still adopt conventional fret concept. This paper conducts an preliminary information of the innovation of multiscale fret in a guitar that is associated with aspects of ergonomic comfort. In further research, this is expected to be a reference to understand the basic of multiscale fret and a stepping stone in conducting more systematic review regarding the effectiveness of the performance of human-centered musical instruments.

Development and calibration of drum-based rolling resistance testing machine for manual wheelchair components

BACKGROUND: Manual wheelchair users are at a high risk of repetitive strain injuries, carpal tunnel syndrome, and rotator cuff tears due to propelling their wheelchair for mobility. Rolling resistance (RR) is one of the key forces that leads to increased propulsion forces and risk of injuries. OBJECTIVE: To better understand the factors contributing to RR, we iteratively designed, developed, and validated a drum-based testing machine and test method. METHODS: As part of the validation of the system, we tested and compared 4 manual wheelchair wheels under a range of conditions including camber, toe in/out, tire pressure, surfaces, and speed. A treadmill was employed to simulate flat ground RR. RESULTS: A machine was effectively designed, developed, and tested to measure RR. Tire type, surfaces, and toe were found to be the largest contributors to RR. Comparison of the drum-based system to flat ground revealed that an offset can be used to calculate overground RR from drum measurements. CONCLUSIONS: Ongoing work includes performing a comprehensive analysis of the degree to which each factor contributes to RR of commonly used casters and rear-wheels so that the wheelchair sector can work to reduce RR and the associated risk of repetitive strain injuries.

A high prevalence of manual wheelchair rear-wheel misalignment could be leading to increased risk of repetitive strain injuries

Purpose To determine the prevalence and severity of manual wheelchair rear wheel misalignment in community-dwelling manual wheelchair users and estimate the associated increases in rolling resistance (RR) and risk of repetitive strain injuries (RSIs). Materials and Methods Data were collected in an outpatient rehabilitation clinic, a university research laboratory, and at adaptive sporting events in the United States. Two hundred active, self-propelling manual wheelchair users were recruited. Angular misalignment (referred to as toe angle) while the wheelchair was loaded with the user, and the difference between the maximum and minimum toe angle (referred to as slop) with the wheelchair unloaded. Results Average results for toe angle and slop (movement in the rear wheels) were 0.92 and 0.61 degrees, respectively. Using a lab-based testing method, we quantified the impact of increased RR forces due to misalignment in increased RR forces. Our results indicate that the average toe angle while under load and slop, without loading, measured in the community increase required propulsion force by 3.0 N. Combined toe angle and slop (i.e., the worst-case scenario) added increased propulsion force by 3.9 N. Conclusions We found that rear-wheel misalignment was prevalent and severe enough that it may increase the risk for RSIs and decrease participation. To mitigate this issue, future work should focus on reducing misalignment through improved maintenance interventions and increased manufacturing quality through more stringent standards. Implications for Rehabilitation The work reveals a previously unknown and significant contributor to RR that could have health implications for users who self-propel. Maintenance and repairs should be adjusted to help reduce the impact of misalignment. Our results suggests that WC designers should take additional care to designs wheels and frames to minimize misalignment. Service providers setting up wheelchairs should take additional care to make sure the wheels are aligned. Users should monitor misalignment and prioritize maintaining or having their chair repaired when misalignment occurs.

The Dynamic Computer Workstation-A Pilot Study of Clinical and Biochemical Investigation during Work at Static Respectively Mobile Keyboards.

A large and increasing number of the work force in the population spend their work hours at the keyboard. There is evidence that repetitive high levels of static work, or extreme working postures involving the neck–shoulder muscles are an increased risk for chronic neck–shoulder pain. The aim of this study was to investigate the effect of dynamic computer working (DCW), using a mobile application to the desk surface, on pain characteristics and biomarkers in office workers. We included 10 female subjects. All subjects answered questionnaires about general health, pain intensity and characteristics. The pressure pain threshold (PPT), neck range and motion, neck and shoulder strength were measured. Microdialysis was conducted in trapezius muscle. Measurements were performed before and 4 weeks after DCW. Multivariate analysis, orthogonal partial least square discriminate analysis (OPLS-DA) and univariate analysis paired test, Wilcoxon, was performed. There was significant improvement in reported neck pain, quality of life, and psychological distress after 4 weeks DCW. The PPT and strength in neck and shoulder were significantly increased after DCW. A significant OPLS-DA model showed clear separation between the samples collected before and after 4 weeks DCW. In conclusion, these results show that keyboard work at a movable desk application might decrease the risk of repetitive strain injuries in the neck and shoulder muscles.

A Semi-Automated Tuberculosis Testing Workflow Reduces Manual Hazardous Sample Handling and Hands-On Time: A Proof-of-Concept Study.

A central tenet of good diagnostic laboratory practice is protecting laboratory staff from contact with sample-borne pathogens and dangerous chemicals. Automated sample-processing systems can reduce or eliminate the risk of exposure to infectious samples while providing results on par with, or better than, those from manually processed samples. In addition, hands-free automated processing may enable analysts to focus on higher order activities while eliminating the risk of repetitive strain injuries associated with manual pipetting. Here, we describe a semi-automated tuberculosis interferon-γ release assay (IGRA) workflow that includes an automated high-throughput sample-processing system. The system automates cap removal, automates sample mixing and aspiration of blood from lithium heparin collection tubes, and aliquots blood samples into multiple blood assay tubes for downstream testing without manual intervention. We show that automated results are comparable to manual methods without risk of analyst exposure or repetitive strain injury.

REPETITIVE MOTION AND POSTURAL ANALYSIS OF MACHINE OPERATORS IN MECHANIZED WOOD HARVESTING OPERATIONS

The objective of this study was to evaluate operators’ posture and repetitive motions in the mechanized wood harvesting operations, aiming comfort, safety, and health of forest operators. The study was carried out in the clearcutting of pine stands located in Parana State, Brazil. Data were obtained in tree cutting operations with feller buncher and wood processing with harvesters, in which three operators in each machine were filmed during their workday. The typical postures were evaluated by Rapid Whole-Body Assessment (REBA) and Rapid Upper-Limb Assessment (RULA) methods, while repetitive motions were evaluated by Latko, Silverstein and Strain Index (SI) methods. The results showed the feller buncher operators remained long period seated in static position, with fists turning outside the neutral line and without pauses for recovery, although REBA and RULA methods had identified low postural risk. In wood processing operation, the spinal column and neck were the most affected body parts, presenting medium postural risk and the need for investigations and quickly changes by REBA and RULA methods, respectively. Besides that, wood harvesting operations with feller buncher and harvester were classified as high repeatability, showing more than 30 thousand repetitive motions in a workday, indicating high risk of Repetitive Strain Injuries (RSIs) and Musculoskeletal Disorders (MSDs) in the operators. Therefore, it is concluded the ergonomic measures are necessary to improve operators’ comfort and health.

Innovation and employee injury risk in automotive disassembly operations

Engineering innovations in car disassembly systems are studied for affects on system operators’ risk of repetitive strain injury (RSI). Objective instrumented measures of injury risk factors with synchronised video-based task analyses were used to examine changes in operators’ RSI risk during two cases of engineering innovation: (1) a shift in industrial model from traditional extracting saleable parts to line-based full material recovery, and (2) the prospective effects of a simulated ‘Lean’-inspired process improvement in the line system. Both cases of innovation showed significantly increased movement speeds and reduced muscular recovery opportunities, implying increased RSI risk. This case study reveals a mechanism by which innovation may increase RSI risks for operators. Managers responsible for engineering innovation should ensure their teams have the tools and mandate necessary to control injury hazards as part of the development and design process. These cases suggest how failure to manage RSI hazards in the innovation process may allow increases of injury risks that can compromise operational performance. This ‘innovation pitfall’ has implications for operator health and organisational sustainability. Alternative pathways are discussed.

P211 A roadmap for successful robotic automation of next generation sequencing based HLA typing

Aim DNA library preparation for next generation sequencing (NGS) consists of several hundred material transfer and wash steps, which are time consuming, labor intensive, and increase the risk of repetitive strain injury. Robotic liquid handlers can automate and standardize library preparation, but few HLA laboratories have experience with high-complexity robotic platforms. We sought to evaluate the use of robotics for library preparation in conjunction with a NGS based HLA typing assay. Methods A Beckman Coulter Biomek NXp Span-8 robotic liquid handler was acquired along with the vendor supplied robotics method for the Illumina TruSight HLA v2 sequencing panel. The robotics method was first optimized with a series of runs using water, 50% glycerol, 85% ethanol, and AMPure beads. Next, DNA and reagents were run to identify sample viscosity and reagent issues. After each run, issues were communicated to the vendor for method improvement. The finalized method was run on 78 DNA samples over seven runs to assess the quality of normalization, pooling, sequencing, and reproducibility of results. Results Robotic issues were encountered with pipette calibration, labware definitions, proper labware selection, and efficiency. To add complexity, these issues had subtle compounding effects on the overall success of the method, which required that each be addressed individually and in detail. Eleven versions of the method were subsequently produced and tested to ensure robustness and consistency. The finalized method produced consistent high quality sequencing metrics on the NGS typing platform which agreed with the known HLA typing results. Conclusions Detailed documentation of issues by lab staff and clear communication with the vendor allowed for a rapid and iterative improvement of the robotics method. The lessons learned during the implementation process formed a roadmap that allowed for successful implementation of a robotics platform for NGS based HLA typing.

Important clinical components of the physiobikefit

A large body of practical and clinical experience indicates that bike set up and peddling techniques can both significantly improve cycling performance and minimise the risk of repetitive strain injuries. It is important however that any adjustments made to bike geometry can be accommodated within the rider's musculoskeletal abilities.

성인 및 청소년의 엄지손가락 반복사용에 따른 근 피로한계 비교

Abstract: According to the frequent use of mobile devices, risk of repetitive strain injury for the finger joints wasincreasing recently. The purpose of this study was to investigate the difference of muscular endurance limit of thethumb between adults and children. A total of thirty subjects (15 adults: 41.0± 7.9 years and 15 children: 9.5± 2.7years) was recruited for this experiment. Maximum voluntary contraction (MVC) of the thumb was measured for100 trials for each subject by using a push-pull gauge. From the maximum peak value obtained, three main factors(MVC, endurance limit, and fatigue index) were defined to quantify fatigue characteristics of the thumb flexor muscle.The experimental results showed that the mean of MVC, endurance limit, and fatigue index of the children wereapproximately 50% compared to the adults (p < 0.001). From the results of Pearson correlation test, the endurancelimit was highly correlated with weight, age, hand length rather than height. Based on this study, children are morevulnerable to repetitive task using the thumb such as text/SNS messaging, gaming, and scrolling.Key words: repetitive strain injury, thumb, muscle fatigue, muscular endurance limit, mobile device

Keyboard Shortcut Users: They Are Faster at More than Just Typing

Software efficiency may be important for employees who want to be viewed as valuable assets in a company. One efficient method people can employ is the use of the keyboard to issue commands (KICs) because KICs are faster than other methods, e.g. menus or icons. Furthermore, using KICs may reduce the risk of repetitive strain injuries (RSIs). This paper examines the question of whether KIC users utilize different types of interaction techniques more quickly than non-KIC users. Participants were exposed to five conditions, each consisting of different computer tasks. One condition was used to determine KIC usage, the independent variable. The other four conditions were used to objectively measure performance in time (i.e., efficiency), one of the dependent variables. After each condition, participants completed the NASA-TLX survey, which was used as a subjective measure of workload, the second dependent variable. Task performance correlated strongly or moderately with KIC usage for all conditions, which indicates that KIC users finished all tasks more quickly than other users—even when they used other techniques than KICs to accomplish those tasks. There was no relationship between KIC usage and subjective workload.

Keyboard Shortcut Users: They Are Faster at More than Just Typing

Software efficiency may be important for employees who want to be viewed as valuable assets in a company. One efficient method people can employ is the use of the keyboard to issue commands (KICs) because KICs are faster than other methods, e.g. menus or icons. Furthermore, using KICs may reduce the risk of repetitive strain injuries (RSIs). This paper examines the question of whether KIC users utilize different types of interaction techniques more quickly than non-KIC users. Participants were exposed to five conditions, each consisting of different computer tasks. One condition was used to determine KIC usage, the independent variable. The other four conditions were used to objectively measure performance in time (i.e., efficiency), one of the dependent variables. After each condition, participants completed the NASA-TLX survey, which was used as a subjective measure of workload, the second dependent variable. Task performance correlated strongly or moderately with KIC usage for all conditions, which indicates that KIC users finished all tasks more quickly than other users—even when they used other techniques than KICs to accomplish those tasks. There was no relationship between KIC usage and subjective workload.

Nem tudo brilha na produção de jóias de Limeira - SP

Limeira-SP é uma cidade onde opera um dos principais pólos de produção de jóias e bijuterias, que tem como característica o uso da mão-de-obra informal nos domicílios, nas atividades de montagem, soldagem e cravação de peças. Compreender o funcionamento do setor bem como identificar os riscos à saúde dos trabalhadores são os objetivos do artigo. Foi aplicado um questionário em 22 escolas da Rede Estadual de Ensino. Foi constatado que 27% dos alunos trabalham montando e soldando jóias e bijuterias, uma população de 8.340 indivíduos, dos quais 20% dos estudantes possuem idade abaixo de 17 anos (erro amostral de 5,7%). Os alunos referem queixas de dores em membros superiores, existindo correlação entre trabalhar com jóias e bijuterias e as citadas queixas, indicando a existência de riscos de Lesões por Esforços Repetitivos - LER. Os resultados indicam a necessidade de políticas públicas e esforço da sociedade para regular e encontrar alternativas sustentáveis para o setor.

Development and design of a dynamic armrest for hydraulic-actuation joystick controlled mobile machines

Standard armrests used in conjunction with joysticks of heavy mobile machinery have been proven to inadequately meet operator needs, resulting in excessive static loading of shoulder musculature. During joystick operation, the trajectory of the user's forearm is governed by the motion of the controller, which creates horizontal and vertical movement of the forearm. The vertical motion of the forearm in the forward and backward motion create postures that stationary armrests cannot support thereby generating increased muscle activation and risk of repetitive strain injuries. The current paper describes the design process used in creating a dynamic armrest that replicates the operator's natural motion trajectories. By incorporating the natural motion paths into a dynamic armrest, the postural requirements and muscular activation of the operator's shoulder may be reduced.

Aiming and clicking in young children’s use of the computer mouse

The present study investigated the abilities of young children to aim and click with a computer mouse. Young children have not yet fully developed their motor skills and they are therefore more likely than adults to click next to targets on the computer screen. Because in educational software incorrect clicks could result in incorrect answers, children may initiate a laborious aiming process that increases the risk of repetitive strain injuries. The present study evaluated some factors that could affect the difficulty of aiming and clicking for children from Kindergarten 2 and Grade 1. Adults participated to serve as a reference group. The results show that the accuracy of mouse clicks and aiming speed are related the size of targets. The shape of targets or a context of distracting objects did not affect accuracy or speed. This work recommends the use of targets of at least 1 centimeter wide and tall in the design of software for young children.

연령별 휴대폰 사용실태에 관한 연구

With the new technology and the popularization of mobile phone. the functions and designs of mobile phone have been varied rapidly. However. based on the user's level of familiarity on mobile phone function and knowledge of information technology. the using behaviors of mobile phone. especially between the young users who are well acquainted with the latest function and technology and the over middle-aged users who are relatively not. would be quite different. A survey was conducted to investigate the various using behaviors of mobile phone in different age groups. The total number of six hundred and sixty-seven people from age seventeen to sixty participated in this study. The participants were divided into young group (age between 17 to 29) and the over middle-aged group (age between 40 to 60) to compare the difference group considered design. price. and function of the mobile phone as three important factors. on the other hand. the over middle-aged group considered quality of communication. price and ease of use as three important factors. All the respondents of the young group know how to use the text messaging function. however for the over middle-aged group. 40% of the respondents knows how to use the text messaging function. The over middle-aged group seemed mainly use the mobile phone for voice communication. however the young group had a tendency to communicate each other with short text message rather than through voice conversation. Twenty percentage of young group responded that they had an experience of pain or discomfort at the thumb. the thenar eminence area. or carpus area during pushing the mobile phone keypad. The excessive frequent use of keypad may cause the risk of repetitive strain injury (RSI). The results of this study could provide important information to understand the way of using mobile phone in different age groups. and also could be used to design and market the mobile phone.<br/>

Contractures of the Hand in a Boy with Duchenne Muscular Dystrophy Associated with Use of a Computer Game Console

Summary A boy with Duchenne muscular dystrophy played finger-operated computer games for up to six hours daily. He experienced fatigue, stiffness and occasional pins and needles which might have led to contractures in his hands. His condition led him to adopt a sedentary game but also predisposed him to stiff joints. Physiotherapists need to be aware of this propensity. A joy-stick operated game might carry less risk of repetitive strain injury – for all children.

Continuous feedback to promote self-management of rest breaks during computer use

Short rest breaks at regular intervals can reduce musculoskeletal discomfort and the risk of repetitive strain injury during intensive computer work, but may seriously disrupt some tasks. As an alternative, two laboratory experiments tested if application of ergonomic principles of feedback control could improve worker self-management of discretionary rest breaks. Undergraduate typists ( N = 31, N = 30) entered lines of randomized words for about 1 h. Typists received scheduled breaks unless their discretionary breaks reached a target level of 30 s every 10 min. Typists in treatment conditions received continuous feedback indicating how their discretionary breaks compared to the target level, but typists in control conditions did not. Feedback in one experiment was task-integrated to reduce distractions. Typists in the feedback conditions controlled discretionary breaks better than controls, and also responded favorably to the continuous feedback. Typists receiving task-integrated feedback reported less task disruption and back discomfort than controls. Mood and cardiac response were unaffected in both studies, but error rates were lower in the feedback condition of one experiment. These results indicate that computer users can utilize continuous feedback about rest break behavior to improve self management of discretionary rest breaks, with no untoward effects on performance, well-being, or user acceptance.

Occupational Repetitive Strain Injuries and Gender in Ontario, 1986 to 1991

Repetitive strain injuries (RSIs) in Ontario were examined with respect to gender for the period 1986 to 1991, using data from Ontario Workers' Compensation Board systems. Technical issues surrounding analysis of workplace injuries and theoretical suggestions raised by the data are discussed. Analyses revealed that the risk of RSIs for women is greater than that for men. Furthermore, women receive compensation benefits because of RSIs for a longer period than do their male counterparts, which may indicate a longer-term effect of RSIs on women.