Predictors of Duration of Injury-Related Disability Leave

Background: Medical leave due to workplace injury is common in the US workforce and creates significant financial drain on the economy. Although there are abundant data relating the duration of medical leave to specific injuries, there is a paucity of research correlating the duration of medical leave with a patient’s attributes or occupation. The primary objective of this study is to examine the influence of specific occupational and patient characteristics on the medical leave taken by employees. Methods: Using records accessed from a major academic institution of 2449 patients reporting medical leave, 547 patients met the inclusion criteria. Worker occupations were divided into three groups based on level of physical activity required for the job. Patient characteristics available for analysis included age, education level, sex, type of injury, and type of medical claim. The association between these factors and duration of disability leave was analyzed using bivariate and multivariable analysis as well Kaplan-Meier survival analysis.Results: Bivariate regression analysis showed that days off work were significantly correlated to physical requirement group (p= 0.0002), age (p=0.00357), injury type (p=0.002), insurance claim type (p=0.0001), injured body part (p=0.001), and level of education (p= 0.0005). On multivariable analysis, physical group, level of education, body part injured, and claim type remained statistically significant. Patient sex did not show significant correlation to days off work.Conclusions: Age, claim type, level of physical requirement, body part injured, and educational requirement are independent predictors of days lost from work following injury. Physicians should be aware of these factors when estimating length of disability leave to patients and their employers.

The Role of Motor Learning on Measures of Physical Requirements and Motor Variability During Repetitive Screwing

We investigated whether physical requirements and motor variability decreased over days in novices during a repetitive screwing task. Fifty-seven subjects performed one hour of repetitive screwing and fastening on three days, separated by 2–7 days. The average physical requirement and relative cycle-to-cycle variability (coefficient of variation, i.e., CV) were calculated from continuous recordings of electromyography of four arm muscles (biceps brachii, triceps brachii, flexor carpi radialis, extensor digitorum), forearm acceleration, and electrocardiography. Muscle activity levels, heart rate, and forearm acceleration decreased from day 1 to day 2 (range: ~4% to ~20%) and/or 3 (range: ~4% to ~28%). Not all muscles showed a similar pattern. Activity of the extensor digitorum and biceps brachii decreased already between days 1 and 2 (range: ~6% to ~13%), whereas activity of the flexor carpi radialis and triceps brachii decreased between days 1 and 3 (range: ~13% to ~20%). No changes in physical requirement were detected between days 2 and 3. Relative motor variability did not change across days, except that variability of forearm acceleration increased from day 1 to 3 (~5%). This study found consistent changes in physical requirements and indicated that several arm muscles show earlier decreases of muscular activity, like the extensor digitorum, compared to other body parts, like the flexor carpi radialis. Moreover, movement strategies may develop differently than muscle activation strategies, based on the different developments of physical requirements and motor variability. The development of physical requirements in industrial tasks is part of daily living and starts at task onset, highlighting the importance of task familiarization and the randomization of experimental conditions in scientific studies.

A design of HDPE flexible spline of harmonics gear

In a design of a small robot, selecting a servo-motor is the most important method in designing process. Common miniature servo motors for small robots normally use conventional gear train set or planetary gear set. Gear train and planetary gear give very low gear ratio whereas its weight is too heavy. On the other hand, Harmonic gear system, which is developed from strain wave drive gearing, gives better the highest gear ratio per weight than those two gear systems. In this paper, a plastic flexible spline gear is presented in order to replace a thin metal spline. The plastic flexible spline gear is designed under gear physical requirement and servo-motor properties. The spline thicknesses are varied in a range of 1 to 4 millimetre and simulations on strength, fatigue, and torque requirement are made to verify the designs.

PENGARUH KARET ALAM SIKLIK (CYCLIC NATURAL RUBBER) TERHADAP RONGGA ASPAL MODIFIKASI

Penelitian ini bertujuan untuk mengetahui pengaruh karet alam siklik terhadap rongga aspal modifikasi. Tahapan peneltian meliputi pembuatan aspal modifikasi dengan menyampur aspal murni dengan karet alam siklik, pengujian persyaratan fisik aspal, pembuatan benda uji dan pengujian marshall. Berdasarkan pengujian sifat fisik aspal diperoleh data bahwa keseluruhan aspal modifikasi memenuhi persyaratan fisik aspal. Setelah pembuatan benda uji, dilakukan pengujian marshall untuk memperoleh rongga aspal meliputi VIM, VMA dan VFA. Nilai VIM pada penambahan 0 phr, 1 phr, 2 phr, 3 phr, dan 4 phr adalah 3,65%, 5,41%, 4,27%, 3,84%, dan 2,88%. Nilai VMA sebesar 15,52%, 17,26%, 16,07%, 15,80%, dan 15,17%. Nilai VFA sebesar 76,48%, 68,72%, 73,54%, 75,76%, dan 81,34%. Diperoleh kesimpulan bahwa karet alam siklik bisa dijadikan sebagai bahan memodifikasi aspal dan berpengaruh terhadap rongga aspal.This research aimed to determine the effect of cyclic natural rubber (CNR) to cavity of modified bitumen. The steps of the research were mixing the pure bitumen with CNR, testing bitumen physical requirement, making the specimen, and testing the cavity of modified bitumen with marshall method. Testing showed that all the modified bitumen met the physical requirement. After making specimen, marshall method was used to determine the cavity of bitumen, including VIM, VMA, and VFA. VIM in addition of 0 phr, 1 phr, 2 phr, 3 phr, and 4 phr was 3,65%, 5,41%, 4,27%, 3,84%, and 2,88%. The value of VMA was 15.52%, 17.26%, 16.07%, 15.80% and 15.17%. The value of VFA was 76.48%, 68.72%, 73.54%, 75.76% and 81.34%. The conclusion of this study was CNR could be used as material for bitumen modified and had the effect on bitumen cavity.

Comparative Research on Different Solutions of a High-Performance Thin-Film Polarizing Beam Splitter

In the process of fabricating an ultra-high precision thin-film polarizing beam splitter (PBS), which is the key element in a new kind of Y-shaped cavity dual-frequency laser, low production yield is a serious problem. Based on the robust design method by controlling sensitivity of optical films to production errors, response characteristics to production errors of different kinds of PBSs are comparatively studied. By experimental study of robust design, essential determinant of sensitivity of PBSs to production errors is found to be the physical requirement that the propagation angle should be larger than the critical angle of total reflection of the interface between the substrate and outer space. By fulfilling the physical requirement, optimum incidence angle has been found by repeated robust design on different incidence angles, and a high-performance thin-film PBS with low sensitivity to production errors has been designed. The coating structure of the obtained PBS is simple and it is easy to be batch manufactured, which will make a positive impact on fabrication, engineering and application of the new Y-shaped cavity dual-frequency laser.

ANÁLISE DA CARGA DE TRABALHO FÍSICO EM ATIVIDADES DE IMPLANTAÇÃO FLORESTAL EM ÁREAS DECLIVOSAS

Esta pesquisa teve o objetivo de avaliar a carga de trabalho físico em atividades de implantação florestal em áreas declivosas no sul do Espírito Santo e propor uma reorganização ergonômica para melhoria dos níveis de saúde, bem-estar e satisfação dos trabalhadores. A carga de trabalho físico foi avaliada por intermédio do levantamento da frequência cardíaca, com o uso de monitores de frequência cardíaca nas atividades de construção de cercas, roçada manual, capina química, marcação de covas, coroamento, coveamento manual, enchimento de covas, adubação pré-plantio e plantio. A maior exigência física no trabalho foi verificada na atividade de coveamento manual (125 bpm), sendo esta classificada como moderadamente pesada. A menor exigência física no trabalho foi observada na atividade de adubação pré-plantio, com frequência cardíaca média de 87 bpm, sendo classificada como atividade leve. Foram verificadas diferenças significativas entre as atividades de implantação (médias da carga cardiovascular) pelo teste de Scott-Knott ao nível de 5%, e a necessidade de reorganizar o ambiente de trabalho com inserção de pausas orientadas.Palavras-chave: Ergonomia florestal; frequência cardíaca; plantio florestal; fisiologia do trabalho florestal. AbstractAnalysis of the load of physical work in activities of forest implementation insteepareas.This research had the objective to evaluate the load of physical work in activities of forest implementation in steep areas in the south of the Espírito Santo, Brazil and to propose an ergonomic reorganization for improvement of the levels of health, well-being and satisfaction of the workers. The load of physical work was evaluated by the survey of the cardiac frequency with the use of monitors of cardiac frequency in the activities of construction of fencing, manual mowing, weeding chemical, marking of graves, weeding, manual pit, filling of pits, adubation pre-planting and planting. The biggest physical requirement in the work was verified in the activity of manual pit (125 bpm), being classified as moderately heavy activity. The lower physical demands at work were observed in adubation pre-planting, frequently average cardiopath of 87 bpm, being classified as light activity. Significant differences had been verified enter the averages of the cardiovascular load and necessity to reorganize the environment of work with insertion of target pauses.Keywords: Forestry ergonomics; cardiac frequency; forestry activities; physiology of forest work.

ANÁLISE ECONOMÉTRICA DO PREÇO EXTERNO DO COMPENSADO BRASILEIRO

Esta pesquisa teve o objetivo de avaliar a carga de trabalho físico em atividades de implantação florestal em áreas declivosas no sul do Espírito Santo e propor uma reorganização ergonômica para melhoria dos níveis de saúde, bem-estar e satisfação dos trabalhadores. A carga de trabalho físico foi avaliada por intermédio do levantamento da frequência cardíaca, com o uso de monitores de frequência cardíaca nas atividades de construção de cercas, roçada manual, capina química, marcação de covas, coroamento, coveamento manual, enchimento de covas, adubação pré-plantio e plantio. A maior exigência física no trabalho foi verificada na atividade de coveamento manual (125 bpm), sendo esta classificada como moderadamente pesada. A menor exigência física no trabalho foi observada na atividade de adubação pré-plantio, com frequência cardíaca média de 87 bpm, sendo classificada como atividade leve. Foram verificadas diferenças significativas entre as atividades de implantação (médias da carga cardiovascular) pelo teste de Scott-Knott ao nível de 5%, e a necessidade de reorganizar o ambiente de trabalho com inserção de pausas orientadas.Palavras-chave: Ergonomia florestal; frequência cardíaca; plantio florestal; fisiologia do trabalho florestal. AbstractAnalysis of the load of physical work in activities of forest implementation insteepareas.This research had the objective to evaluate the load of physical work in activities of forest implementation in steep areas in the south of the Espírito Santo, Brazil and to propose an ergonomic reorganization for improvement of the levels of health, well-being and satisfaction of the workers. The load of physical work was evaluated by the survey of the cardiac frequency with the use of monitors of cardiac frequency in the activities of construction of fencing, manual mowing, weeding chemical, marking of graves, weeding, manual pit, filling of pits, adubation pre-planting and planting. The biggest physical requirement in the work was verified in the activity of manual pit (125 bpm), being classified as moderately heavy activity. The lower physical demands at work were observed in adubation pre-planting, frequently average cardiopath of 87 bpm, being classified as light activity. Significant differences had been verified enter the averages of the cardiovascular load and necessity to reorganize the environment of work with insertion of target pauses.Keywords: Forestry ergonomics; cardiac frequency; forestry activities; physiology of forest work.