Rest Schedule Research Articles

2B-Alert Web 2.0, an Open-Access Tool for Predicting Alertness and Optimizing the Benefits of Caffeine: Utility Study.

BackgroundOne-third of the US population experiences sleep loss, with the potential to impair physical and cognitive performance, reduce productivity, and imperil safety during work and daily activities. Computer-based fatigue-management systems with the ability to predict the effects of sleep schedules on alertness and identify safe and effective caffeine interventions that maximize its stimulating benefits could help mitigate cognitive impairment due to limited sleep. To provide these capabilities to broad communities, we previously released 2B-Alert Web, a publicly available tool for predicting the average alertness level of a group of individuals as a function of time of day, sleep history, and caffeine consumption.ObjectiveIn this study, we aim to enhance the capability of the 2B-Alert Web tool by providing the means for it to automatically recommend safe and effective caffeine interventions (time and dose) that lead to optimal alertness levels at user-specified times under any sleep-loss condition.MethodsWe incorporated a recently developed caffeine-optimization algorithm into the predictive models of the original 2B-Alert Web tool, allowing the system to search for and identify viable caffeine interventions that result in user-specified alertness levels at desired times of the day. To assess the potential benefits of this new capability, we simulated four sleep-deprivation conditions (sustained operations, restricted sleep with morning or evening shift, and night shift with daytime sleep) and compared the alertness levels resulting from the algorithm’s recommendations with those based on the US Army caffeine-countermeasure guidelines. In addition, we enhanced the usability of the tool by adopting a drag-and-drop graphical interface for the creation of sleep and caffeine schedules.ResultsFor the 4 simulated conditions, the 2B-Alert Web–proposed interventions increased mean alertness by 36% to 94% and decreased peak alertness impairment by 31% to 71% while using equivalent or smaller doses of caffeine as the corresponding US Army guidelines.ConclusionsThe enhanced capability of this evidence-based, publicly available tool increases the efficiency by which diverse communities of users can identify safe and effective caffeine interventions to mitigate the effects of sleep loss in the design of research studies and work and rest schedules.

ASSESSMENT LEVEL OF PHYSICAL ACTIVITY AND PSYCHO-EMOTIONAL HEALTH STATUS OF THE BOGOMOLETS NATIONAL MEDICAL UNIVERSITY STUDENTS UNDER CONDITIONS OF DISTANCE LEARNING ORGANIZATION

deterioration of epidemiological situation in the country and educational institutions due to the spread of coronavirus infection prompted the government to change the educational process and move it to distance learning. Psychological support and assistance of future doctors are critical, as, in our country, there is a growing shortage of medical staff, namely doctors, during the COVID-19 pandemic. One way to solve the above problems is to study students of higher medical institutes (SHMI) views on the transition to distance learning, which is essential to identify weaknesses and issues in the higher medical institutions of our country and to purposefully take measures to improve the pedagogical process based on identified needs. The aim of our research includes assessment of the level of physical activity and psycho-emotional health of the higher medical education seekers' of the healthcare field specialty 222 medicine using distance education under quarantine conditions (additional psycho-emotional impact) and establish ways for improving it with a combination of distance education and different psycho-emotional impact. A survey was conducted among 155 Bogomolets National Medical University SHMI of the 1st and 2nd year of study. Developed by us questionnaire have included questions about the assessment of the educational process organization (at the classroom and at "distance"), SHMI routine (work and leisure), namely amount of their spending time for sports and on the gadget use. Significant attention had been given to SHMI assessment of their health, psycho-emotional state, and level of adaptation during the study. During processing results of the motor activity study of surveyed SHMI had been revealed an insufficient level of motor activity. Thus, only 14% of SHMI do morning gymnastics, 29% of respondents go in for sports three times a week. We also found that a significant proportion of respondents have not enough duration of night sleep, which negatively affects the study's success and potentially worsens their health. Analysis of the surveyed SHMI work and rest schedule shows that most SHMI sleep at night on weekdays for 6 to 7 hours (72%). 25% of respondents have a sleep duration of up to 5 hours and only 3% of respondents have slept more than 9 hours. However, chronic insomnia can gradually lead not only to diseases but also to disorders such as, decreasing concentration memory impairment, reduce performance and work efficiency. Significant mental and psycho-emotional overload during distance education requires establishing of physiological day regime.
 Assessment of the functional state of SHMI allows timely attention and identifies certain risk groups among SHMI. Currently, distance education is developing rapidly due to quarantine restrictions, the rapid development of the Internet, and the constant improvement of communication methods. Therefore, it is essential to improve the effective organization of distance education in terms of providing SHMI with the required level of knowledge and paying due attention to problem issues.

ASSESSMENT LEVEL OF PHYSICAL ACTIVITY AND PSYCHO-EMOTIONAL HEALTH STATUS OF THE BOGOMOLETS NATIONAL MEDICAL UNIVERSITY STUDENTS UNDER CONDITIONS OF DISTANCE LEARNING ORGANIZATION

deterioration of epidemiological situation in the country and educational institutions due to the
 spread of coronavirus infection prompted the government to change the educational process and move it to dis-tance learning. Psychological support and assistance of future doctors are critical, as, in our country, there is a
 growing shortage of medical staff, namely doctors, during the COVID-19 pandemic. One way to solve the aboveproblems is to study students of higher medical institutes (SHMI) views on the transition to distance learning,
 which is essential to identify weaknesses and issues in the higher medical institutions of our country and to pur-posefully take measures to improve the pedagogical process based on identified needs. The aim of our research
 includes assessment of the level of physical activity and psycho-emotional health of the higher medical educationseekers’ of the healthcare field specialty 222 medicine using distance education under quarantine conditions
 (additional psycho-emotional impact) and establish ways for improving it with a combination of distance educa-tion and different psycho-emotional impact. A survey was conducted among 155 Bogomolets National Medical
 University SHMI of the 1st and 2nd year of study. Developed by us questionnaire have included questions aboutthe assessment of the educational process organization (at the classroom and at «distance»), SHMI routine (workand leisure), namely amount of their spending time for sports and on the gadget use. Significant attention hadbeen given to SHMI assessment of their health, psycho-emotional state, and level of adaptation during the study.During processing results of the motor activity study of surveyed SHMI had been revealed an insufficient levelof motor activity. Thus, only 14% of SHMI do morning gymnastics, 29% of respondents go in for sports threetimes a week. We also found that a significant proportion of respondents have not enough duration of night sleep,which negatively affects the study’s success and potentially worsens their health. Analysis of the surveyed SHMI
 work and rest schedule shows that most SHMI sleep at night on weekdays for 6 to 7 hours (72%). 25% of respon-dents have a sleep duration of up to 5 hours and only 3% of respondents have slept more than 9 hours. However,
 chronic insomnia can gradually lead not only to diseases but also to disorders such as, decreasing concentrationmemory impairment, reduce performance and work efficiency. Significant mental and psycho-emotional overloadduring distance education requires establishing of physiological day regime. Assessment of the functional state of SHMI allows timely attention and identifies certain risk groups amongSHMI. Currently, distance education is developing rapidly due to quarantine restrictions, the rapid developmentof the Internet, and the constant improvement of communication methods. Therefore, it is essential to improve theeffective organization of distance education in terms of providing SHMI with the required level of knowledge andpaying due attention to problem issues.

{Protection, Resilience, Efficiency and Prevention} (PREP), preparing workers and employers for a changing climate

BACKGROUND AND AIM: Expensive, often inaccessible, treatment, early death, and economic hardship faces millions of workers in Latin America and Asia due to Chronic Kidney Disease of nontraditional cause (CKDnt). Strenuous work in extreme heat without sufficient rest and hydration is an important driver. We established the Adelante Initiative workplace intervention to prevent CKDnt and kidney injury among workers at a sugarcane mill in Nicaragua. The Initiative focused on heat stress mitigation, hydration and rest systems including electrolyte solutions, mobile tents, rest schedules and education, for workers and management, combined with an organizational assessment to address barriers to implementation. METHODS: PREP builds on Adelante, investigating: 1) impact of the intervention on workforce health and productivity; 2) economic and social impacts of CKDnt 3) economic burden on health systems; 4) public and private-sector policy gaps and solutions. RESULTS:Workers with the heaviest workload had a 12-fold higher risk (95%CI=3.93-35.4) of kidney injury than those with lower workload in the same environment. Despite implementation challenges at the mill including inconsistent provision of shade, hydration and mandated rest, there was a 72% (95%CI=50-90%) reduction of incident kidney injury post intervention. Economic burden on households and health systems is considerable. Public and private sector policies are either nonexistent or inadequate to provide guidance for prevention, or to support detection and treatment of CKDnt. However, the inclusion of initial investments in technical assistance for workplace protections within the development sector and some industries is encouraging. CONCLUSIONS:PREP lays the groundwork to expand to other industries and geographies at-risk for heat stress and CKDnt. Occupational heat stress and resulting CKDnt require increased attention and resources for surveillance, prevention and treatment. Climate change means more extreme temperatures in already impacted regions, and regions further north and south of the equator, putting more workers at risk of CKDnt. KEYWORDS: Temperature extremes and variability, Health co-benefits, Socio-economic factors, Occupational exposures, Exposure assessment-general

Assessment of the Work–Rest Schedule of the Russian Members of the International Space Station Crews 40/41–53/54 Using the Flight Monitoring Data

For retrospective (post-mission) analysis of the work–rest schedule (WRS) of Russian ISS crewmembers, missions from 40/41 to 53/54 were grouped depending on whether there were three (ISS 40/41–49/50) or two cosmonauts (ISS 50/51–53/54). Signs of strenuous WRS were noted in 62% of mission weeks in the first group and in 94% of weeks in the second group. The cosmonauts had to work overtime irrespective of mission durations. In the first group, overtime averaged 25 min daily or 3 h weekly. In the second group, daily and weekly overtimes averaged 1 h 51 min or 13 h, respectively, which is four times longer than in the first group. Sleep hours during missions shifted clockwise and counterclockwise. The magnitude of sleep shifting varied between 30 min and 12 h. As a rule, sleep duration was 6–7 h and, in the opinion of most cosmonauts, was sufficient for good rest and recovery.

PARTICULARITIES OF DRIVER’S WORK AND REST SCHEDULE CONDITIONS IN ORGANIZED CHILDREN CARRIAGE IN INTERCITY CONNECTION

Introduction. The article is devoted to the description of the shedule development particularities and a drivers’ work and rest schedule adjustment in an organized children carriage considering their age in an intercity connection. During the interurban transportation after first four hours and thirty minutes of uninterrupted driving, a special break for the rest is provided for drivers on the way lasting at least 45 minutes. This period can be divided into two or more parts, but the first part should last at least 15 minutes and the last one at least thirty minutes. At the same time children of different age groups perceive long distant travels variously due to their physiological development. The restriction of physical activity during a long time may have a negative impact on children’s physical and mental state. Children may have some problems with behavior control during long distant travels, it may lead to a travel rules violation, they remove their seat belts, start to walk around the bus, etc. The dependencies of the covered distance and time on a children’s age were identified based on the study results of the intercity children carriage process. The findings may be applied in a bus route timetables development, a drivers’ work and rest schedule adjustment during an organized children carriage in an intercity connection and also when planning transport infrastructure objects along popular tourist routes or frequently used transportation directions for students.The purpose of article is the description of a traffic schedule particularities development and a drivers’ work and rest schedule adjustment in an organized children carriage considering their age in an intercity connection. The scientific novelty lies in methodology used for a drivers’ work and rest schedule adjustment which depends on a distance and travel time in an organized children carriage by buses in an intercity connection and on the age of the carried children.Materials and techniques. While writing the article the methods of a passengers carriage theory, a statistical and systematic analysis, a transport process theory and also some other scientific methods and techniques were used.Results. The results have advisory nature and are proposed for use in a drivers’ work and rest schedule adjustment in an organized children carriage considering their age in an intercity connection.Discussion and conclusion. For the carriage of different aged children the scheme of traffic according to a children age group should be chosen. 4 age groups of children each of which correspond to a certain traffic and rest time on the way were identified during the study.

Risk Reduction of Occupation Diseases by Optimization of Schedule of Work and Rest on Example of Workers of Electrolytic Production

The article considers the actual question of risk estimation of non-evident professional diseases. On the basis of the conducted assessment of the acting schedule of the work of a pot operator of molten salts of one of the departments of the Urals aluminum smelter and determined unaccounted peculiarities of daily dynamics of the behavior of biological processes in the human organism while work scheduling, the authors have developed rational shift schedule, in which the time of a worker’s night shift is maximally cut. The proposed schedule is aimed at preventing accidents and decreasing the risk of occupation diseases of employees. The provided material has a great practical significance as the main principle of the management system of professional risks is health maintenance in the process of production activity.

A multicomponent ergonomic intervention involving individual and organisational changes for improving musculoskeletal outcomes and exposure risks among dairy workers

A field intervention study was implemented to evaluate the effects of individual (physical exercise programme and worker ergonomics training) and organisational changes (optimising work–rest schedule and revised task procedure) on musculoskeletal outcomes and their exposure risks among milking workers in a dairy plant. A questionnaire survey (including the Cornell Musculoskeletal Discomfort Questionnaire [CMDQ]) and direct observations of working postures by using the Quick Exposure Check (QEC) method were used at baseline and 12-month follow-up. Shoulder, lower back and neck discomfort were found to be the most common problems. The results showed significant improvements in the frequency (neck, shoulder, lower back, forearm and knee symptoms), severity (shoulder, lower back and knee symptoms) and interference with work (particularly due to lower back symptoms) as well as in the exposure risks to musculoskeletal problems (using the QEC method) after the intervention. The findings support the effectiveness of implemented multiple component intervention for improving musculoskeletal health and exposure risks in the studied occupational group.

Specifying and Mitigating Thermal Stress Effects on Cognition During Personal Protective Equipment Use.

To report present understanding concerning selected task and environmental factors influencing the changing performance capacity associated with use of personal protective equipment (PPE). Much knowledge is available concerning change in complex cognitive capacities under the effects of thermal stress. Our science can inform critical care facilities as to remediation strategies such as work-rest schedules to minimize performance error in highly cognitively demanding circumstances such as intensive care units. The present exposition draws from the state-of-the-art understanding concerning thermal stress effects on cognition and workload in complex and demanding tasks. The summation and synthesis of HF/E findings provides important insights into combinatorial effects of forms of stress, typically dealt with only as discrete sources in traditional standards and regulations. The identified interaction between ascending thermal stress and cognitive task demand provides an instance of the plurality of ways HF/E can specify performance limitations in safety-critical circumstances, as witnessed in the current pandemic. Accumulated HF/E insights provide systematic ways in which to address and ameliorate the combined forces of physical and cognitive stress on medical personnel constrained to use varying forms of PPE. These principles extend beyond this specific domain to all who are required to work in differential and isolated microclimates. To minimize the possibility of critical and life-threatening error in intensive care facilities which necessitate PPE use, we need principled work-rest ratio and heat stress mitigation guidance. To promote health, we need to champion healthy work practices in our health workers. HF/E insights can help achieve this important goal.

Preventing kidney injury among sugarcane workers: promising evidence from enhanced workplace interventions

ObjectivesTo assess if improvement of working conditions related to heat stress was associated with improved kidney health outcomes among sugarcane harvest workers in Chichigalpa, Nicaragua, a region heavily affected by...

Сон в Антарктиде: от проблем с засыпанием до понимания проблем

From the first expeditions, adaptation to the harsh environment of Antarctica, the expeditionists complained of a trouble sleeping. During a long stay on the continent, the polar explorers are exposed to a large number of extreme environmental factors both at the station and outside it, but the main physical factors of sleep disturbances are considered to be the peculiarities of light and photoperiod. Recently, more attention has been paid to clarifying the role of psychological adaptation to the Antarctica conditions, regarding the living in a small group and confined space. Existing methods to prevent the sleep disorders, first of all, comprise the manipulating with light parameters, activity and rest schedules. A thorough preliminary selection of expeditionists to establish the necessary psychological climate, thinking about gender and multicultural characteristics of adaptation can also be considered with the perspective of preventive measures. At the same time, little attention is paid to the investigation of the role of 'non-core' factors (chronotype, personality traits and features of personal adaptation to the extreme environment of Antarctica), as well as forced contact with cold, affecting sleep. Probl Cryobiol Cryomed 2020; 30(1): 3-23

Sleep-wake behaviors exhibited by shift workers in normal operations and predicted by a biomathematical model of fatigue.

To compare rail workers' actual sleep-wake behaviors in normal operations to those predicted by a biomathematical model of fatigue (BMMF). To determine whether there are group-level residual sources of error in sleep predictions that could be modeled to improve group-level sleep predictions. The sleep-wake behaviors of 354 rail workers were examined during 1,722 breaks that were 8-24 h in duration. Sleep-wake patterns were continuously monitored using wrist-actigraphy and predicted from the work-rest schedule using a BMMF. Rail workers' actual and predicted sleep-wake behaviors were defined as split-sleep (i.e. ≥2 sleep periods in a break) and consolidated-sleep (i.e. one sleep period in a break) behaviors. Sleepiness was predicted from the actual and predicted sleep-wake data. Consolidated-sleep behaviors were observed during 1,441 breaks and correctly predicted during 1,359 breaks. Split-sleep behaviors were observed during 280 breaks and correctly predicted during 182 breaks. Predicting the wrong type of sleep-wake behavior resulted in a misestimation of hours of sleep during a break. Relative to sleepiness predictions derived from actual sleep-wake data, predicting the wrong type of sleep-wake behavior resulted in a misestimation of sleepiness predictions during the subsequent shift. All workers with the same work-rest schedule have the same predicted sleep-wake behaviors; however, these workers do not all exhibit the same sleep-wake behaviors in real-world operations. Future models could account for this group-level residual variance with a new approach to modeling sleep, whereby sub-group(s) may be predicted to exhibit one of a number of sleep-wake behaviors.

The mental workload of harvester operators working in steep terrain conditions

The use of modern multi-functional forestry machines has already been associated with central nervous system fatigue induced by high mental workload. As these machines are being used under increasingly difficult terrain conditions, further knowledge is required on the expected aggravation of operators’ mental workload, so that suitable work/rest schedules can be developed. Within such a context, the aim of this study was to gauge aggravations of mental workload derived from increasing slope gradient. Measurements of eye activity were obtained from a representative harvester operator working in corridors with the following mean inclinations: 9%, 23% and 47%. The duration, frequency and trajectory of eye movements were used to determine the harvester operator’s mental workload, on the assumption that worsening work conditions would be reflected by increased eyeball activity. The number of fixations during the performance of all tasks increased with the increasing slope gradient. Similarly, fixation duration increased with slope gradient. The mean duration of saccades when working on a 23% slope was 5% shorter compared to work under a 9% gradient. A further significant shortening of saccade duration (~22%) occurred when working on a 47% slope. The good match between eye activity cycles and work cycles, visible especially on steep slopes, indicates that mental workload is related to work conditions. Overall, operating a forest harvester on steep slopes results in a greatly increased mental workload and calls for suitable rest schedules.

Sleep deprivation and a non-24-h working schedule lead to extensive alterations in physiology and behavior.

Most organisms on Earth possess circadian rhythms in their physiology and behaviors that allow them to resonate with the cycling environment over a 24-h period. However, in human society, a substantial quantity of jobs requires non-24-h working and rest or shift schedules, which causes more or less misalignment in circadian rhythms and disorders as a consequence. In this work, we conducted a sleep deprivation (SD) and non-24-h working and rest schedule (8 h on and 4 h off) experiment over 10 d in total and measured the changes in a series of physiologic and cognitive parameters. The results show that although the subjects could sleep during the schedule, their sleepiness increased significantly. Actigraphy data suggest that a 12-h schedule might result in chronic SD. Along with the increased sleepiness revealed by the Karolinska Sleepiness Scale questionnaire, the neurobehavioral psychomotor vigilance test data reveal that, compared with the control period, the reaction time of the subjects was significantly delayed. The saliva insulin levels were significantly changed in the morning in SD and non-24-h cycles. Salivary biochemical parameters were also altered, including aspartate aminotransferase and K+. 16S rRNA-based analysis of the salivary microbiota showed differentially changed patterns in bacteria composition and concentration. Together, these data demonstrate that an abnormal working and rest schedule might produce comprehensive interference with circadian rhythms, metabolism, and cognition.-Ma, H., Li, Y., Liang, H., Chen, S., Pan, S., Chang, L., Li, S., Zhang, Y., Liu, X., Xu, Y., Shao, Y., Yang, Y., Guo, J. Sleep deprivation and a non-24-h working schedule lead to extensive alterations in physiology and behavior.

Роль физических нагрузок в развитии атеросклеротических поражений сосудистой стенки

The main mechanisms of the damaging effect of excessive physical exertion on the cellular structures of the vascular endothelium and the development of systemic pathological conditions associated with this process are covered in this paper. The generally accepted view on the benefits of physical activity for the prevention of cardiovascular disease is not in doubt. However, today various training programs of debatable benefits and risks ratio are widely used. High intensity high volume training is the distinctive feature of this type of physical activity. Violation of the training and rest schedules in this approach often leads to the overtraining syndrome. Understanding the causes of this condition at the molecular and cellular levels may increase the efficiency of training planning for competing athletes and prolong sport participation of the elderly athletes and sports enthusiasts. Keywords: atherosclerosis, inflammation, excessive exercise, arterial stiffness.

Improvement of the analysis methods of the working hours` distribution of locomotive crews by the types of train operation in freight traffic

The work is aimed to increase the efficiency of cargo transportation by railway transport by improving the work organization of locomotive crews. The research is based on the methods of organization of operational work of railways and the methods of mathematical statistics. The problem of increasing the use efficiency of working hours of locomotive crews in freight traffic is considered in the article. Based on the statistical data processing of drivers’ routes, the working hours` distribution of locomotive crews for different types of train operation in freight traffic for four locomotive depots was performed. During the research, a conditional division of the working time of locomotive crew by the type of work was performed, if the crew worked with trains of various categories. The algorithm for assigning the idle time and empty running of locomotive to certain types of train operation was also developed. The work originality lies in the fact that it improves the methods of analysis of the working hours` distribution of locomotive crews for certain types of train operation in freight traffic. The developed methods give an opportunity to evaluate the work specifics of individual locomotive depots and provide the initial data for planning the use of locomotives and the work and rest schedule of locomotive crews.

Le travail posté et de nuit et ses conséquences sur la santé : état des lieux et recommandations

There are in France several millions of shift-workers and night-workers (20 to 25% of employees). These workers are therefore subject to variations in their working and rest schedules. These regular schedule changes are associated with repeated desynchronization of circadian biological clock. The negative impacts on sleep are insomnia, drowsiness, and reduced sleep time in 24hours. There is also a proven effect on the occurrence of a metabolic syndrome, with a likely effect on obesity, type 2 diabetes, blood pressure and coronary artery disease. There is a likely effect on the occurrence of cancer (including breast cancer). Night working is not recommended for pregnant women because of the risk of miscarriage, prematurity and intrauterine growth retardation.

Impact of loading and work rest intervals on muscle micro-trauma

PurposeTo examine whether rest intervals of different durations (“High Rest, Low Frequency” v. “Low Rest, High Frequency”), and load at different force exertion levels with different repetition frequencies (“High Load, Low Repetition” v. “Low Load, High Repetition”) have an impact on muscle micro-trauma, as such micro-trauma over repetitive loading and long-term muscle overuse can lead to musculoskeletal disorders (MSDs). MethodTwenty-four adult males (mean age: 24.1 years; 3.6 SD) were randomly assigned to one of 4 bicep muscle eccentric exercise treatment groups (n = 6; “High Load, Low Repetition; High Rest, Low Frequency”, “High Load, Low Repetition; Low Rest, High Frequency”, “Low Load, High Repetition; High Rest, Low Frequency”, or “Low Load, High Repetition; Low Rest, High Frequency”) with non-dominant arm to induce muscle micro-trauma reactions in serum. Subjects in all treatment groups had equivalent total work volume, total rest duration and total work duration for comparison of muscle micro-trauma between and within the treatment groups. Muscle micro-trauma biomarker serum Creatine Kinase (CK) level was measured pre-exercise (Day 0) and post-exercise on Days 1, 2, 4, and 8. ANOVA with repeated measures was used to examine significance of rest and load-repetition combination over pre and post experiment days, as well as possible interactions. ResultCK levels fluctuated significantly across different “Day” (P = 0.0115). Interaction was disordinal and significant between “Day” and “Rest” (P = 0.0000), and “Load” and “Rest” (P = 0.0322). Under “High Load, Low Repetition” condition, CK levels on Day 4 were significantly higher than on Days 0 and 2; CK levels on Day 8 were significantly higher than Day 0. CK level peaked on Day 4. Under “Low Rest” Condition, CK level on Days 4 and 8 are significantly higher than Day 0. ConclusionShorter but more frequent rest intervals led to more extreme muscle micro-traumatic responses than the longer but less frequent ones, especially under “High Load, Low Repetition” condition when non-dominant bicep brachii was subscribed with eccentric exercise regimen. Relevance to industryThe exploration of how rest scheduling affects progression of microtrauma from a biomechanical and molecular level in this study furthers current understanding of the early stage development of WMSDs. With future studies’ further research and confirmation, the findings of this study may be able to serve as a first attempt to guide shift scheduling and job design at manufacturing facilities.

Impact of solutions for goods transportation on business efficiency and traffic safety

Abstract The paper addresses the impact of efficiency and results of solutions applied to transport goods on business efficiency indicators and their relation with the consequences of violating road traffic regulations, work and rest schedule of vehicle crews, weight and dimension restrictions imposed on trucks. The degree of dissociation between adopted systems to evaluate solutions is analyzed for various participants through the whole supply chain. As a result, a conflict of interests is found between businessmen owning goods, transport companies, consumers, and the society. The basic requirements to logistics in the form of three goals (faster, cheaper, better) develop behavioral models and patterns to take decisions leading to unsafe situations on roads and violations of various requirements to transportation. Following interests of businessmen assessing efficiency using criteria of ROA (return on assets) and the value for business owners results in similar decisions. The paper describes a model of developing ROA elements that are affected by criteria for making decisions during goods transportation and decisions provoking violation of various rules and requirements. This model can provide a basis for a quantitative analysis of the factors’ impact on logistics costs and on the value of assets. Model development options depend on the selected method of economic analysis. This model allows revealing primary causes for road accidents, based on reaching the goals to be met through decisions in logistics and goals underlying business efficiency. The approach can also be used in determining trends in motivation of transport operators in observing the requirements and improving transport laws.

The impact of work rest scheduling for prolonged standing activity.

Prolonged standing can cause discomfort on the body of the workers and can lead to injury and occupational disease. One of the ergonomic intervention is through improving the work-rest scheduling. The purpose of this study are to identify the fatigue level from the perception of the worker and to investigate the impact of the work-rest scheduling to the standing workers for 12 h working time with a different gender. This study involved two methods which are self-assessment of the worker and direct measurement by using electromyography (EMG). For self-assessment, 80 workers have been interviewed using questionnaire in order to identify the fatigue level. For direct measurement, EMG was attached to the 15 selected workers at their respective leg and lower back to analyse the muscle efforts. In terms of perception, the results show the discomfort and fatigue level at the lower body region in the following order as foot ankle, lower back and leg. There is a significant difference between gender on discomfort pain for foot ankle and leg. The results show short frequent break by 10 min can reduce the fatigue at the leg and infrequent long break is preferable in order to reduce the fatigue at the lower back. In conclusion, it was found that prolonged standing affect the muscle fatigue and discomfort especially lower extremities such as foot ankle, lower back and leg. Besides that, different type of work rest scheduling and gender have significant result towards the muscle fatigue development.