Reducing whole body vibration in forklift drivers

Forklift drivers in warehouses are often exposed to whole body vibration (WBV) during the total day. There is however an association between working as a forklift operator and the development of low back pain. In this study the exposure to WBV was measured in five forklift drivers who performed a standardised order picking task during 10 minutes. The effect of driving surface (uneven concrete vs. new flat concrete), driving speed (15 km/h vs. 8 km/h) and seat suspension (mechanical suspension vs. air suspension) was investigated. Improving the driving surface was the most effective preventive measure by reducing the whole body vibration with 39%, from 1.14 to 0.69 m/s2. Lowering the speed limit resulted in a reduction of WBV with 26% (1.05 vs. 0.78 m/s2). An air suspension seat was 22% more effective compared to mechanical suspension (1.02 vs. 0.80 m/s2). On uneven concrete an air suspension seat performed even better by reducing the WBV by 29% (1.33 vs. 0.95 m/s2). A combination of a new driving surface, limiting the maximum speed and the introduction of an air suspension seat reduced the whole body vibrations below the action limit of 0.5 m/s2 as mentioned in the European directive. None of the interventions were effective enough on their own.     

Computer use and ulnar neuropathy: results from a case-referent study

We aimed to evaluate associations between vocational computer use and 1) ulnar neuropathy, and 2) ulnar neuropathy- like symptoms as distinguished by electroneurography. We identified all patients aged 18-65 years, examined at the Department of Neurophysiology on suspicion of ulnar neuropathy, 2001-2007. We mailed a questionnaire to 546 patients with ulnar neuropathy, 633 patients with ulnar neuropathy-like symptoms, and three community referents per case, matched on sex, age, and primary care centre. From a Job Exposure Matrix we extracted estimates of daily hours of computer use. The analysis was performed by conditional logistic regression.There were a negative association between daily hours of computer use and the two outcomes of interest. Participants who reported their elbow to be in contact with their working table for 2 hours or more during the workday had an elevated risk for ulnar neuropathy (OR=2.16, 95 % CI; 1.06-4.44).The two outcomes were not associated with daily hours of computer use. Findings suggested specific effects of pressure on the elbow, and might be an explanation for the overweight of left-sided outcomes in this primarily right-handed group. Preventive efforts would then be straightforward by providing appropriate arm support for the left arm and elbow.     

Proper manual handling techniques to prevent low back pain, a Cochrane systematic review

Training and provision of assistive devices are considered major interventions to prevent and treat low back pain (LBP) among workers exposed to manual material handling (MMH). To establish the effectiveness of training and provision of assistive devices in preventing and treating LBP an update of a Cochrane literature review was performed to November 2010. Randomised controlled trials (RCTs) and cohort studies with a concurrent control group (CCTs) were included. Nine RCTs (20.101 employees) and nine CCTs (1280 employees) were included for prevention: six more than in the previous version. No study on treatment was found. None of the included RCTs and CCTs provided evidence that training and provision of assistive devices prevented LBP when compared to no intervention or another intervention.     

Participatory design in lean production: which contribution from employees? For what end?

The proponents of lean production have pointed to the positive effects of the work organization on employees in terms of autonomy, enhanced skills and empowerment mainly by their participation into the continuous improvement of work process. But studies that have examined this issue suggest that the increase in autonomy is not sufficient to compensate for increases work intensity. Participatory design has grown extensively in manufacturing since the 1980's under the impulsion of the Scandinavian socio-technical system approach and it's central in the model of lean production performance. Its main objectives are to improve quality, increase productivity and safety through employee's participation to the reduction of non-value added activities, such as defined by lean production. In the line of the studies on participatory design and continuous improvement the present study examines the functioning of work groups, based on the kaizen model, the aim of which was to improve the proportion of "value-added activities" and working conditions, essentially physical constraints. The main results are consistent with the literature and show that accelerated forms of re-conception activities give employees limited room for maneuver to elaborate solutions based on the analysis of the real activity. This study is part of a broader initiative that goes in the direction of continuous improvement of the design process itself so that it integrates the real constraints of work and propose changes bases on work as it actually takes place, beyond pre-established performance goals bases on the reduction of "non added value activities".     

Preventing Rsi/Wruld: use of esthesiometry to assess hand tactile sensitivity of slaughterhouse workers

This research was conducted with slaughterhouse female workers in the municipality of S?o Miguel do Igua?u, state of Parana, Brazil. The sample was composed of 103 women aged 25 to 40 ( 7.57 years, and the study aimed to verify the nerve conduction of the median nerve. An esthesiometer consisting of a Semmes-Weinstein monofilaments was used to measure the hand skin sensitivity in the region of the median nerve and a Jamar? hand dynamometer, which was used to determine the handgrip strength. About 81% of individuals had normal sensitivity with 0.05 g and average levels of handgrip strength in dominant hand (DH) of 35.30 kgf (( 3.10) and in the non-dominant hand (NDH) of 28.30 ( 3.09 kgf. 14% of individuals had reduced sensitivity, with values equivalent to 0.2 g and 2.0 g (blue and violet) and levels of handgrip strength in the DH equal to 28.10 kgf (( 2.90) and in the NDH of 26.40 kgf (( 3.28). 5% of individuals showed bilateral sensitivity deficit (4.0 g) and levels of handgrip strength in the DH of 16.10 kgf (( 2.10) and in the NDH of 18.20 kgf (( 3.28), resulting in a strong correlation between handgrip strength and sensitivity of the median nerve (r = 0.786) between variables dominant hand (DH) and (r = 0.626) for the non-dominant hand (NDH). It could be concluded that assessing the nerve conduction of the median nerve by hand esthesiometry can be an important tool in preventing the Carpal Tunnel Syndrome.     

The reality of the women who make our lives easier: experience in a company that assemblies electric motors in Venezuela

Objective: intervene a workline throughout ergonomic approach to diminish incidence of Carpal Tunnel Syndrome (CTS). Methods and Materials: an ergonomic intervention study was developed in workstations with highest index of musculoskeletal disorder (MED) associated to cumulative trauma. The Deparis method, Reba and Ocra check list methods were used, also morbility reviewes. National and international ethics criteria were carried out. Results: workers identified 3 fundamental issues using the Deparis method: repetitive activities, postures adopted and uncomfortable furniture. The analysis of the workstation with Reba and Ocra methods before the changes, evidenciated that 56% of postures adopted were high risk postures, the 44% remaining were medium and low-risk. Following the active pause program (APP), furniture changes and work rhythm decrease, was noted that the risk of suffering MED decreased. The morbility review, drop in consults of musculoskeletal system (MES) related to CTS observed. The APP was well accepted by women, but not initially men. Discussion: the research show that when the work rhythm decreases, the symptom of MES related to CTS have a remarkable decrease, also that changes in the furniture, generate great ergonomic differences and changes in the work environment are not possible if workers don't empower the tools to make-it.     

Managing unforeseen events in anesthesia: collective trade-off between "understanding" and "doing"

This study aims to describe how anesthesia teams handle unforeseen events that may affect the patients' health. More precisely, it investigates the mechanisms of decisions made by anesthesia teams to manage unthought-of situations, i.e. situations that have not been foreseen as "possible" ones before their occurrence. An empirical study, based on the analysis of simulated situations, was conducted in a pediatric anesthesia service of a university hospital in France. The results highlighted three ways of managing unthought-of situations (determined management, cautious management and overwhelmed management). They support the hypothesis of a collective cognitive trade-off, whereby teams would behave as virtual operators, with their own collective trade-off between "understanding" and "doing". The discussion of the results questions the assessment criteria, the safety perspectives we adopt and the possible ways to improve the management of unforeseen situations.     

Irregular working times and metabolic disorders among truck drivers: a review

A number of studies to better understand the complex physiological mechanism involved in regulating body weight have been conducted. More specifically, the hormones related to appetite, leptin and ghrelin, and their association to obesity have been a focus of investigation. Circadian patterns of these hormones are a new target of research. The behaviour of these hormones in individuals subject to atypical working times such as shiftwork remains unclear. Shiftwork is characterized by changes in biological rhythms and cumulative circadian phase changes, being associated with high rates of obesity and metabolic syndrome. Truck drivers, who work irregular shifts, frequently present a high prevalence of obesity, which might be associated with work-related factors and/or lifestyle. In this context, the aim of this paper was to discuss the relationship of body mass index, appetite-related hormones and sleep characteristics in truck drivers who work irregular shifts compared with day workers.     

Tire aging: a human factors analysis of failure to warn and inform

A scenario of an automotive accident caused by tire failure is given followed by a human factors analysis of the information available to consumers on tire aging. Consumers have not been told that the age of the tire is a safety concern. It is not easy to decode the date of manufacture on tires. More publicity and prominent warnings are needed to communicate the dangers of older tires. Also, better ways to present the date of manufacture so that consumers can more easily and accurately assess tire age are needed.     

Virtual reality based therapy for post operative rehabilitation of children with cerebral palsy

Virtual reality is the use of interactive replication created with computer hardware and software to impart users with opportunities to engage in environments that appear to feel similar to real world objects and events. The commonest rehabilitation program of cerebral palsy children involves stretching, strengthening, mobilization and various other activities, whereas the use of virtual reality based training (VRBT) for rehabilitation of cerebral palsy is not common. To understand the effect of VRBT a study was formulated. Twenty nine subjects participated (study group--14 and control group--15). Outcome measures were MACS, PBS, level of participation, motivation, cooperation and satisfaction of the child. Results revealed that balance and manual ability were significantly improved in both the groups (Balance: study: t-2.28, p<0.05; control: t-3.5, p<0.01; Manual ability: study: t-5.58, p<0.001; control: t-7.06, p<0.001). PBS had significantly greater improvement in the study group (t-t-2.02, p<0.05). Level of participation, motivation, cooperation and satisfaction of the child were also reported to be significantly higher among the study group as compared with control group. To the author's best knowledge, this is the first study on using the VR-based therapy for the postoperative rehabilitation of children with CP which need further elaboration with larger sample size.