Effectiveness of lumbar support with built-in massager system on spinal angle profiles among high-powered traffic police motorcycle riders: A randomised controlled trial.

Traffic police riders are exposed to prolonged static postures causing significant angular deviation of the musculoskeletal, including the lumbar angle (L1-L5). This postural alteration contributes to awkward posture, musculoskeletal disorders and spinal injury, especially in the lower back area, as it is one of the most severe modern diseases nowadays. Thus, the study aimed to evaluate the effect of lumbar support with a built-in massager system on spinal angle profiles among traffic police riders. A randomised controlled trial (pre-testpost-test control design) was used to assess spinal angle pattern while riding the high-powered motorcycle for 20 minutes. Twenty-four traffic police riders were randomly selected to participate and 12 riders were assigned to the control group and 12 riders to the experimental group. The pre-test and post-test were conducted at a one-week interval. Each participant was required to wear a TruPosture Smart Shirt (to monitor spinal posture). The TruPosture Apps recorded the spinal angle pattern. The data indicated that the police riders using motorcycle seat with lumbar support and built-in massager system showed a huge improvement in maintaining posture which only involves slight spinal angle deviation changes from the spinal reference angle throughout the 20 minutes ride. The data collected then were analysed using the Mann-Whitney test and Wilcoxon signed-ranked test to verify a statistically significant difference between and within the control and experimental groups. There were significant differences in all sensors between the control group and experimental groups (p<0.05) and within the experimental group. According to the findings, it can be said that the ergonomic intervention prototype (lumbar support with built-in massager system) successfully helps to maintain and improve the natural curve of the spinal posture. This indirectly would reduce the risk of developing musculoskeletal disorders and spinal injury among traffic police riders.

Ergonomics in the anaesthetic workplace: Guideline from the Association of Anaesthetists.

Ergonomics in relation to anaesthesia is the scientific study of the interaction between anaesthetists and their workspace environment in order to promote safety, performance and well-being. The foundation for avoiding pain or discomfort at work is to adopt and maintain a good posture, whether sitting or standing. Anaesthetists should aim to keep their posture as natural and neutral as possible. The successful practice of anaesthesia relies on optimisation of ergonomics and lack of attention to detail in this area is associated with impaired performance. The anaesthetic team should wear comfortable clothing, including appropriately-sized personal protective equipment where necessary. Temperature, humidity and light should be adequate at all times. The team should comply with infection prevention and control guidelines and monitoring as recommended by the Association of Anaesthetists. Any equipment or machinery that is mobile should be positioned where it is easy to view or reach without having to change the body or head position significantly when interacting with it. Patients who are supine should, whenever possible, be raised upwards to limit the need to lean towards them. Any item required during a procedure should be positioned on trays or trolleys that are close to the dominant hand. Pregnancy affects the requirements for standing, manually handling, applying force when operating equipment or moving machines and the period over which the individual might have to work without a break. Employers have a duty to make reasonable adjustments to accommodate disability in the workplace. Any member of staff with a physical impairment needs to be accommodated and this includes making provision for a wheelchair user who needs to enter the operating theatre and perform their work.

Evaluation of a novel stair-climbing transportation aid for emergency medical services.

Acute and planned transportations of patients are major tasks for emergency medical services (EMS) and often result in substantial physical strains with a major impact on the workers' health, because current transportation aids cannot provide sufficient support, especially on stairs. A new stair-climbing and self-balancing approach (SEBARES) has been developed and its usability is evaluated in the context of this paper. Twelve participants operated a prototype in a transportation scenario and user forces, user joint angles and the perceived usability were evaluated. Results show that user forces were within long-term acceptable ergonomic limits for over 90% of the transportation time and a mainly healthy upright posture of the back could be maintained. This resulted in a healthy working posture for 85% of the time, according to the OWAS method, and a good perceived usability. A comparison to the most ergonomic aid according to literature, a caterpillar stair chair, reveals that similar upright postures are assumed, while the operation of SEBARES required only 47% of the forces to operate the caterpillar stair chair. A comparison to a previous field study indicates a reduction of strenuous working postures by a factor of three, which further confirms the ergonomic advantages of this concept.

Historical Trend of Work-Related Musculoskeletal Disorders in the Meatpacking and Auto Industries, 1980s-Present.

Occupational Applications This paper provides a historical overview of the rise of Work-Related Musculoskeletal Disorders (WMSDs) in the U.S. from the 1980s to the present, with a special focus on the two industries with the highest recorded rates: Meatpacking and Auto Assembly. The activities underlying this account amount to a major occupational health success story (although still incomplete) in the recognition of these disorders and the development of a nation-wide effort for prevention. An obstacle in creating the data presented here was that the system of recordkeeping changed in multiple ways, making it difficult to compare WMSD rates over time. The work summarized here evaluated the effect of these changes and combined temporal segments that were judged to be the most accurate to create an overall trend line. These results can aid in: 1) showing the overall history of the recognition and prevention of WMSDs, 2) understanding the effects of the recordkeeping changes, and 3) allowing international comparisons of the trends.

An Online Method to Detect and Locate an External Load on the Human Body with Applications in Ergonomics Assessment.

In this work, we propose an online method to detect and approximately locate an external load induced on the body of a person interacting with the environment. The method is based on a torque equilibrium condition on the human sagittal plane, which takes into account a reduced-complexity model of the whole-body centre of pressure (CoP) along with the measured one, and the vertical component of the ground reaction forces (vGRFs). The latter is combined with a statistical analysis approach to improve the localisation accuracy, (which is subject to uncertainties) to the extent of the industrial applications we target. The proposed technique eliminates the assumption of known contact position of an external load on the human limbs, allowing a more flexible online body-state tracking. The accuracy of the proposed method is first evaluated via a simulation study in which various contact points on different body postures are considered. Next, experiments on human subjects with three different contact locations applied to the human body are presented, revealing the validity of the proposed methodology. Lastly, its benefit in the estimation of human dynamic states is demonstrated. These results add another layer to the online human ergonomics assessment framework developed in our laboratory, extending it to more realistic and varying interaction conditions.

Reducing postural load in order picking through a smart workwear system using real-time vibrotactile feedback.

Vibrotactile feedback training may be one possible method for interventions that target at learning better work techniques and improving postures in manual handling. This study aimed to evaluate the short term effect of real-time vibrotactile feedback on postural exposure using a smart workwear system for work postures intervention in simulated industrial order picking. Fifteen workers at an industrial manufacturing plant performed order-picking tasks, in which the vibrotactile feedback was used for postural training at work. The system recorded the trunk and upper arm postures. Questionnaires and semi-structured interviews were conducted about the users' experience of the system. The results showed reduced time in trunk inclination ≥20°, ≥30° and ≥45° and dominant upper arm elevation ≥30° and ≥45° when the workers received feedback, and for trunk inclination ≥20°, ≥30° and ≥45° and dominant upper arm elevation ≥30°, after feedback withdrawal. The workers perceived the system as useable, comfortable, and supportive for learning. The system has the potential of contributing to improved postures in order picking through an automated short-term training program.

An observational ergonomic tool for assessing the worn condition of slip-resistant shoes.

Worn shoes are known to contribute to slip-and-fall risk, a common cause of workplace injuries. However, guidelines for replacing shoes are not well developed. Recent experiments and lubrication theory suggest that the size of the worn region is an important contributor to the shoe tread's ability to drain fluid and therefore the under-shoe friction. This study evaluated a simple test for comparing the size of the worn region relative to a common object (AAA and AA battery) as a means of determining shoe replacement. This study consisted of three components involving slip-resistant shoes: Experiment #1: a longitudinal, mechanical, accelerated wear experiment; Experiment #2: a longitudinal experiment where the same shoes were tested after each month of worker use; and Experiment #3: a cross-sectional experiment that exposed participants to a slippery condition, while donning their own worn shoes. The COF (Experiments #1 and #2); under-shoe fluid pressure (all experiments); and slip severity (Experiment #3) were compared across outcomes (fail/pass) of the battery tests. Larger fluid pressures, lower coefficient of friction, and more severe slips were observed for shoes that failed the battery tests compared with those passing the tests. This method offers promise for assessing loss in friction and an increase in slip risk for slip-resistant shoes.

Influence of virtual keyboard design and usage posture on typing performance and muscle activity during tablet interaction.

This study aimed to determine the effects of virtual keyboard designs and postures on task performance and muscle activity during tablet use. Eighteen healthy adults were randomly assigned to one of three postures (DESK, LAP, BED) to complete six sessions of 60-minute typing on a tablet with three virtual keyboards (STD, WIDE, SPLIT) twice in an experimental laboratory. Keystroke dynamics and muscle activity of the forearm and neck-shoulder regions were measured by electromyography. The split virtual keyboard was found to be associated with faster typing speed (SPLIT vs STD, p = .015; SPLIT vs WIDE, p < .001) and decreased muscle activity of extensor digitorum communis (SPLIT vs STD, p = .021). Lap posture was associated with faster typing speed (p = .018) and higher forearm muscle activity (p < .05). Typing performance decreased (p < .001) with elevated neck extensor muscle activity (p = .042) when the task duration prolonged. The split virtual keyboard showed potential to improve tablet ergonomics under various postures. Practitioner Summary: Tablets have become widely used for a variety of tasks and have gradually expanded into the realm of mobile productivity and education. Adequate designs of virtual keyboards for tablets show the potential for increased task performance and decreased muscle activity pertinent to typing activity and posture constraints imposed by non-traditional work positions. Abbreviations: WPM: words per minute; IKI: inter-key press interval; EMG: electromyography; EDC: extensor digitorum communis; FDS: flexor digitorum superficialis; CES: cervical erector spinae; UT: upper trapezius; EA: electrical activity; MVC: maximum voluntary contraction; APDF: amplitude probability distribution function.

Development and Experimental Verification of an Ergonomic Backpack.

Carrying a heavy school backpack has extensively been reported as a prime cause of children's body strain. It is suggested that the load should not exceed 10 percent of the child's body weight; however, ensuring this requires continuous monitoring. The study explores how ergonomically designed school backpack based on the user anthropometric data (n = 280) and ergonomic parameters help reduce force concentration on shoulders and back. It provides a validation process of the developed prototype by experimental verification. The developed design was assessed in a comparison experiment with a commercially available local school backpack. An experimental study was used which recruited thirty healthy college students (aged 19 to 23 years). Two independent variables evaluated were school backpack type (developed backpack versus commercial one) and load levels as a percentage of body weight. Three load levels were employed 10%, 15%, and 20%. These variables were measured on the responses: bag comfort scale and the percent of maximum voluntary contraction (%MVC) of six muscles (right and left of erector spine, right and left of external abdominal oblique muscle, and right and left of trapezius). The developed backpack provided astonishing performance at levels of 15% and 20% of body weight in terms of subjective measure and electromyography (EMG) responses. It also showed that increasing the carried weight more than 10% result in reducing activity on the erector spinal muscles, while it increases on abdominal oblique muscles. The developed backpack design confirmed the efficiency of its bases by distributing the carried weight among the trunk through side pockets, attached to the body through two upper and lower straps. It helped the body to distribute the carried weight and avoid concentrating pressure on specific areas.

Increasing standing tolerance in office workers with standing-induced back pain.

Sit-stand desks are popular however many people have standing-induced low back pain (LBP). People with LBP have fewer standing weight shifts compared with back-healthy people. Participants were classified as standing-tolerant or intolerant. Participants were provided sit-stand desks for 12 weeks. Participants were assigned to intervention (graded standing exposure and exercise) or control (no instruction) conditions. Participants reported weekly sitting time and average/worst LBP. Standing weight shifts and LBP were re-assessed post-intervention. All groups decreased sitting time (range: 30-50%) over 12 weeks. Sitting time and average LBP were correlated in all standing-intolerant individuals, worst LBP and sitting time were correlated for intervention group only. All standing-intolerant individuals increased standing weight shifts and decreased LBP after 12-weeks. Standing-intolerant individuals benefitted from 12-weeks of sit-stand desk use regardless of intervention. Motivated individuals with standing-induced LBP may increase standing tolerance with sit-stand desk use. Additional benefits may exist when structured guidance is provided. Practitioner summary: Many people are standing-intolerant due to low back pain (LBP). This lab and field-based study showed some benefits from structured approaches to gradually progress standing time when transitioning to standing work. Using a sit-stand desk for 12 weeks resulted in decreased LBP and sitting time in standing-intolerant people. Abbreviations: LBP: low back pain; OSPAQ: Occupational Sitting and Physical Activity Questionnaire; VAS: visual analog scale; GRF: ground reaction force; WeekVASMAX: worst low back pain reported on visual analog scale for prior week; WeekVASAVE: average low back pain reported on visual analog scale for prior week; ICC: intraclass correlation coefficient; LabVASMAX: worst low back pain reported on visual analog scale during lab-based standing; LabVASAVE: average low back pain reported on visual analog scale during lab-based standing; FvR,L: vertical ground reaction force for right and left force plate; BWSSMALL: small (10-29% body weight) body weight shift; BWSLARGE: large (> 30% body weight) body weight shift; ActivPALSED: ActivePAL data for sedentary time; ActivPALSTND: ActivePAL data for standing time; ANOVA: analysis of variance; Standing Intolerant-INT: standing intolerant participants assigned to intervention condition; Standing Intolerant-CON: standing intolerant participants assigned to control condition; Standing Tolerant-INT: standing tolerant participants assigned to intervention condition; Standing Tolerant-CON: standing tolerant participants assigned to control condition; SI: standing intolerant; ST: standing tolerant; INT: intervention; CON: control.

Curved TVs improved watching experience when display curvature radii approached viewing distances: Effects of display curvature radius, viewing distance, and lateral viewing position on TV watching experience.

Although watching TV often involves multiple viewing distances and viewers, less attention has been paid to the effects of display curvature radius, viewing distance, and lateral viewing position on TV watching experience. This study examined the effects of four display curvature radii (2300R, 4000R, 6000R, and flat), two viewing distances (2.3 m and 4 m), and five lateral viewing positions (P1-P5; 0, 35, 70, 105, and 140 cm off-center) on seven TV watching experience elements (spatial presence, engagement, ecological validity, negative effects, visual comfort, image quality, and user satisfaction). Fifty-six individuals (14 per display curvature radius) were seated in pairs to watch videos, each time at a different viewing position (2 viewing distances × 5 paired lateral viewing positions). The spatial presence and engagement increased when display curvature radius approached a viewing distance and lateral viewing position approached P1, with 4000R-4m-P1 (display curvature radius-viewing distance-lateral viewing position) providing the best results. Lateral viewing position alone significantly affected five TV watching experience elements; the spatial presence and engagement decreased at P3-P5, and ecological validity, image quality, and user satisfaction decreased at P4-P5. However, display curvature radius alone did not appreciably affect TV watching experience, and viewing distance alone significantly affected visual comfort only, with a 4-m viewing distance increasing visual comfort. This study demonstrated that effective display curvature radii for watching TV are viewing distance-dependent, and less off-center lateral viewing positions (P1-P2) are recommended for TV watching experience. Finally, among the TV watching experience elements, engagement explained user satisfaction to the greatest degree.

Application of a genetic algorithm to the keyboard layout problem.

The number of people who use computers for business and personal purposes increases as technology grows. The application of ergonomic practices on computer workstations reduces the musculoskeletal discomfort experienced and increases the overall satisfaction of the users. Keyboards are available in various systems, from computers to mobile devices, and have difference shapes and sizes. The keyboard size and shape is known to influence the user's upper extremities. Alternative keyboard designs help diminish the pain in the arms that occurs due to awkward arm postures. Most previous studies tried to optimize the keyboard layout based on ergonomic typing and the frequency of letters' co-occurrence. This research considers the frequency of the appearance of the most used 3,000 words in the English language. First, the frequency of each letter pair is calculated by the Text Analyzer. Then, a genetic algorithm is applied to design an ergonomically optimized keyboard to minimize the total distance of finger travel among the selected alphanumeric characters. The results showed that the distance travelled obtained by the proposed keyboard layout is less than that for the QWERTY keyboard in all different types of texts, in which an average of 6.04% improvement was achieved. Therefore, the proposed design can be used for keyboards to reduce time and fatigue.

Impact of Obesity on Surgeon Ergonomics in Robotic and Straight-Stick Laparoscopic Surgery.

STUDY OBJECTIVE: Work-related musculoskeletal symptoms (WMSs) are reported to be increasing in surgeons performing minimally invasive procedures. Therefore, we investigated the use of inertial measurement units (IMUs) and electromyography (EMG) sensor recorders to record real-time information on the muscle movement/activity required to perform training exercises in simulated in normal and high body mass index (BMI) models. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: Four consultant gynecologic oncology surgeons experienced in complex straight-stick (SS) laparoscopic and robotically assisted (RA) surgery. INTERVENTIONS: Three exercises (hoops onto pegs and wire chase) using SS and RA surgery on 2 abdominal models: normal BMI and high BMI. MEASUREMENTS AND MAIN RESULTS: We measured time to complete exercise and surgeon muscle movement/activity. The time to complete all exercises was significantly lower for RA surgery as compared with SS laparoscopy (p <.05 or better). The movement of the surgeons' core was significantly greater in high BMI SS laparoscopy compared with normal BMI SS laparoscopy for exercises 1 and 2 (p <.001). Muscle usage, as determined by EMG peak, was significantly higher in normal BMI SS laparoscopy and even higher in high BMI SS laparoscopy but was generally flat for all normal and high BMI RA surgery exercises (p <.05 or better). CONCLUSION: Detailed real-time information can be collected through IMUs/EMG sensors. Our results indicate that RA surgery requires less surgeon movements and muscle activity to complete tasks compared with SS laparoscopy, particularly in a high BMI model. The implications of these results are that RA surgery in high BMI patients may therefore have less physical impact on the surgeon compared with SS laparoscopy and may result in lower WMS rates.

Low back pain and some associated factors: is there any difference between genders?

OBJECTIVE: To compare men and women with low back pain and identify the prevalence and some of its associated factors in a population-based sample of adults aged 20 and over a seven day period. METHODS: Cross-sectional study based on a population survey. 600 individuals were interviewed on the following: (1) characteristics of the participants (i.e. demographic, socioeconomic, and labor aspects); (2) physical activity level (IPAQ); (3) musculoskeletal symptoms (Nordic Questionnaire). Descriptive, bivariate, and Poisson regression analyses were performed. RESULTS: Overall prevalence of LBP was 28.8%, being 39.0% in men and 60.9% in women. The measured associated factors in men were age between 36 and 59 years (PR=3.00 [1.31-6.88]) and over 60 (PR=4.52 [2.02-10.12]), smoking (PR=2.47 [1.20-5.11]), fewer years of formal education (0-4 years) (PR=6.37 [2.15-18.62]), and hypertension (PR=2.27 [1.15-4.50]). For women, the associated factors were occupational activities that involved heavy lifting (PR=1.80 [1.03-3.16]), standing posture leaning forward (PR=2.04 [1.20-3.44]), sitting posture leaning forward (PR=2.17 [1.24-3.82]), and sitting at the computer three or more days per week (PR=4.00 [1.44-11.11]). Widowed or divorced participants were more likely to report LBP, in both men (PR=3.06 [1.40-6.66]) and women (PR=2.11 [1.15-3.88]). CONCLUSION: This study reveals high prevalence of low back pain in a seven day period. Older age, low education, hypertension, and smoking were associated with LBP in men. Occupational and ergonomic factors were associated with LBP in women. Marital status was associated with LBP in both genders.

A Novel Dual-Phase Activation-Dependent Foot-Switch Mechanism for Surgical Energy Devices as an Asset in Early Surgical Training: A Proof of Concept Study.

Introduction. Many processes exist that limit or eliminate the incidence of adverse events in general surgery including the World Health Organization safety checklist. Technology and device advancement has a potentially expanding role in the context of surgical safety. Materials and Methods. A dual controlled accessory electrical diathermy footswitch (Permissive diathermy foot switch device or PDf) device concept was developed in an effort to improve patient safety in theatre and enhance opportunities in training. Electrical diathermy is only activated if the senior supervising surgeon and the novice surgeon simultaneously activate their interconnected footswitches. The activation of the PDf accessory footswitch device allows a senior surgeon to exert control on "initiation" of activation of diathermy devices operated by a novice surgeon (foot on pedal) as well as when desiring to deactivate the device (foot off pedal). Results. A process of designing and prototyping was initiated to define the purpose and the functionality of the PDf device up till the stage of a fully functioning prototype. The PDf device was constructed as a final working and tested prototype in association with the local medical engineering department at the Cumberland Infirmary in Carlisle. The device was on a nonbiological model to determine efficacy and safety and passed its laboratory testing phase and was deemed ready for clinical use. Conclusion. We demonstrated the feasibility and functionality of the PDf device and propose a positive role in surgical training in the context of early surgical training and specific circumstances where more control is needed.

Get a grip: multi-method evaluation of handles for tablets on the shop floor.

Tablets on the shop floor need handles because user requirements for handling differ from tablet usage in leisure time. The ergonomics of such handles is under-researched, resulting in a lack of methods for their design and evaluation. In this paper, we present a multi-method evaluation of handles for a shop floor tablet. We combine and compare results of focus groups and the Comfort Questionnaire for Hand tools (CQH) with electromyography (EMG). With a field and a laboratory study, we evaluate four handles in order to identify (i) the most ergonomically rated handle and (ii) the most efficient evaluation method. Results consist of an evaluated prototype, and data that shows the comparability of results from focus groups and questionnaires to results from EMG measurements. Classifying handles as tangible human machine interfaces, we suggest that subjective evaluation with focus groups and CQH is efficient to evaluate their ergonomic quality. Practitioner summary: A handle for a tablet used in production environment is evaluated with different methods. Results show that data from focus groups and questionnaires can be used for evaluation of usability in the future, rendering complex EMG measurements unnecessary and making usability evaluation more efficient. Abbreviation: CQH: comfort questionnaire for hand tools; EMG: electromyography; tHMI: tangible human-machine interfaces; TUI: tangible user interfaces; GUI: user interface; RMS: root mean square; MVC: maximum voluntary contraction; BB: musculus biceps brachii; FCU: musculus flexor carpi ulnaris; FCR: musculus flexor carpi radialis; BR: musculus brachioradialis; FPB: musculus flexor pollicis brevis.

Validity of a novel device for real-time analysis of cyclists' drag area.

OBJECTIVES: To assess the reliability, validity, and sensitivity of a novel device (Notio Konect™) which is purported to provide a real-time analysis of aerodynamic drag area (CdA) during cycling. DESIGN: Observational, cross-sectional study. METHODS: Fifteen trained cyclists rode in an indoor velodrome using three different positions (upright, aero [holding aero bars], and optimized aero [similar to aero, but wearing a time-trial helmet]). They completed six 1-min trials in each position. The CdA was measured with Notio and with two other systems (Track Aero System™ [TAS] and a validated mathematical model). RESULTS: The CdA measured with Notio showed good reliability (intra-class correlation coefficient [ICC]=0.92, 90% confidence interval [CI]=0.89-0.95). Notio showed an almost perfect relationship with both TAS (ICC=0.99, 90% CI=0.98-0.99) and the mathematical model (ICC=0.99, 90% CI=0.98-0.99). However, the CdA values provided by the former (0.308±0.051m2) were significantly higher (albeit with a trivial effect size [ES]) compared with TAS (0.300±0.051m2, p<0.001, ES=0.15) and the mathematical model (0.303±0.051m2, p=0.005, ES=0.09). The CdA was higher in the upright than in the aero position with all systems (all p<0.001, ES=1.84-1.89), and higher in the aero than in the optimized aero position when measured with TAS (p=0.033, ES=0.22) or the mathematical model (p=0.024, ES=0.24), but not with Notio (p=0.220, ES=0.19). CONCLUSIONS: Notio appears to be reliable, strongly correlated to other established systems, and discerns large (upright vs aero) but not small (aero vs optimized aero) variations in riding position. Further research is needed to confirm its validity in outdoor conditions.

Doenças ocupacionais e princípios ergonômicos voltados à formação de profissionais da Odontologia / Occupational diseases and ergonomic principles aimed at training dentistry professionals

Introdução: a alta demanda diária para desempenhar os serviços, aliada ao descuido com o bem-estar laboral, acaba causando uma má postura na hora dos atendimentos, acarretando problemas osteomusculares, dor e, consequentemente, doenças ocupacionais. Objetivo: avaliar o conhecimento dos acadêmicos nos diferentes semestres do curso de Odontologia de uma instituição de ensino superior situada na cidade de Vitória da Conquista ­ Bahia, acerca dos princípios ergonômicos aplicados à prática clínica, além de investigar sintomas associados às doenças ocupacionais. Metodologia: foram selecionados, de forma aleatória, 186 alunos matriculados nas clínicas da faculdade, os quais foram convidados a responder a dois questionários contendo perguntas relacionadas ao conceito de ergonomia e a doenças ocupacionais na Odontologia. Foi aplicado o teste qui-quadradro de Pearson; nos casos em que a frequência esperada foi menor que cinco (n < 5), foi utilizado o teste exato de Fisher (p<0,05). Resultados: cerca de 69% dos graduandos demonstraram total insciênciasobre a ergonomia, 87% apresentaram pouco conhecimento a respeito das doenças ocupacionais da Odontologia, 75% consideraram insatisfatório o conhecimento sobre ergonomia na faculdade e cerca de 76% queixaram-se de dores osteomusculares em pelo menos um local anatômico do seu corpo. Conclusão: o presente estudo demonstrou o pouco conhecimento dos estudantes Oe odontologia a respeito dessa temática e o possível desenvolvimento de doenças osteomusculares ainda na graduação.

Introduction: The high daily demand to perform the services allied to the carelessness with the job well-being lead to a bad posture at the appointments, causing musculoskeletal problems, pain, and, consequently, occupational diseases. Objective: to evaluate the knowledge of students in the different semesters of the Dentistry course of a Higher Education Institution located in the city of Vitória da Conquista - Bahia, on the ergonomic principles applied to clinical practice, and investigate the symptoms associated with occupational diseases. Methodology: 186 students enrolled in the college clinics were randomly selected and invited to answer two questionnaires, containing questions related to the concept of ergonomics and occupational diseases in dentistry. Pearson's chi-square test was applied; in cases that the expected frequency was less than five (n<5), Fisher´s exact test was used (p<0.05). Results: around 69% of the undergraduates demonstrated total unawareness about ergonomics, 87% had little knowledge about occupational diseases in Dentistry, 75% consider the knowledge about ergonomics in college unsatisfactory, and about 76% complained of musculoskeletal pain in at least one anatomical site of their body. Conclusion: the presente study demonstrated Dentistry students have little knowledge about this theme and the possible development of musculoskeletal diseases while still in the undergraduate course.

The effect of using a cycling workstation on mouse dexterity.

This study investigated the effect of using a cycling workstation on mouse dexterity, including if and how this changed with practice. Thirty-four healthy adults were allocated to a sitting group (n = 17) or cycling group (n = 17). All participants completed standardised computer tasks on 6 occasions: baseline and final-all participants were seated; practice 1 to 4-sitting group participants were seated, cycling group participants pedalled on an under desk cycle. Three computer tasks were employed: (1) Tracking (continuous task)-participants used the mouse pointer to track a dot in a figure of 8 pattern at 3 different speeds without a guide then with a guide (2) Aiming (discrete task)-participants moved the mouse pointer to a dot which repeatedly disappeared then reappeared again in different locations, creating the outline of a pentagram (3) Steering (continuous task)-participants steered the mouse pointer around two different pathways. Accuracy was measured during the Tracking and Steering tasks as the root mean square error and penalised path accuracy respectively. Speed was measured during the Aiming task as the movement time. Data was analysed using frequentist and Bayes Factor analyses. During the continuous tasks (Tracking and Steering), accuracy was impaired among participants using the cycling workstation, both compared to their accuracy when seated and to the accuracy of participants in the sitting group. In contrast, no deficits in speed were noted among participants using the cycling work station during the discrete task (Aiming). No learning effects were observed among either group for any tasks. These findings suggest using a cycling workstation may impair the accuracy but not speed of mouse use, regardless of task practice. Overall this supports the implementation of cycling workstations in typical office settings, but suggests cycling workstations may impair productivity among workers performing high precision mouse tasks.