Distribution of oxygen consumption by graded loads during ergonometric testing

Cardiopulmonary exercise monitoring is a valuable method not only for the evaluation of medical health, but also for the assessment of patients with cardiac or pulmonary dysfunction. Spiroergometry provides additional criteria for the assessment of cardiopulmonary efficiency compared to simple ergometry. Maximal oxygen consumption (VO2max) is the most critical variable during spiroergometry. Most submaximal exercise measures provide the heart rate (HR) response to predetermined workloads in equations or nomograms used to predict VO2max. According to previous studies, the heart rate is divided into five fields. In this paper, we are doing a new redistribution of heart rates-to-workloads into seven fields, corresponding to the ergo bar. In other words, an answer is given based on the initial anthropological values of the subjects, when and in which field there will be a mismatch between the lung capacity of the subjects and the power required for that field

Sedentary behavior as a public health issue: Ergonomics as a useful tool

Background: Sedentary behavior carries the risk of musculoskeletal problems, especially in the lumbosacral region of the spinal column.  According to modern lifestyle, this has begun to be a public health issue. Objective: To point to the health risks of working at the computer and present an ergonomic analysis of the typical and improved position of workers in front of the computer, thereby reducing the chances of emergence occupational diseases. Results:  Changing the position of the subjects led to a change in lumbar pressure from 2,818 N/m2 to 351 N/m2. Software analysis of the changed position indicates that this position is acceptable, both for the lumbosacral region of the spine and for the abdominal muscles. Conclusions:  A change in body position will decrease lumbar moment and the load on the lumbosacral region of the spine. Work chair with lumbar support, the right desk height, setting the appropriate position of the monitor, selecting the optimal keyboard and mouse, dividing the workspace into appropriate zones, as well as changing lifestyle and habits should be part of the management of people who spend most of their working time in a sitting position

Ergonomic Analysis and Redesign of Workspace in Order to Minimize Workers’ Workload and Optimize Their Nutrition

The problem related to the inadequate position of workers during lifting heavy loads is the everyday life of many environments, such as industrial halls or warehouses, which often results in the deepening of the worker's spine load problem. An analysis of such a workplace was carried out in this paper. The workloads at specific body zones were determined, whether they were within the prescribed limits or exceeded it, and on that basis a redesign of the workspace was made in accordance to the anthropological values of the model

An ergonomic analysis and computer simulations of nursing activities while raising the patients in hospitals and nursing homes

Background: The use of trolleys for transporting the patients and lifting and lowering them in the trolley is a repeated activity in the daily work of a nurse, and a very common cause of the load of the lumbosacral part of the spine and the consequent pathological deformity, and the onset of clinical symptomatology of painful lumbo-sacral syndrome. The high level of excessive biomechanical stress is associated with the established practice of using standard medical wheelchairs to move patients inside the hospital. The process itself depends on the characteristics of the patient, his or her weight, as well as his/her cooperativeness, but primarily depends on the nurse's mobility. Although nurses strive to be in a position that reduces the load on the lumbosacral part of the spine during practice, this is often impracticable due to the patient's inconsistency. Objective: To present the ergonomic analysis of the medical nurse's workplace while lifting the patient into the wheelchair and to display solution for improving working conditions and prevention of musculoskeletal disorders. Results: By ergonomic module of this software, we got results that present load on lumbosacral region of spine of medical nurses during their daily activities, especially in the position of lifting and lowering patients. It was concluded that maximal spinal loading decreases significantly and becomes less than critical (3,100 N) in the case of a wheelchair that has ability to automatically lift and lower patient. Conclusions: The use of hospital wheelchairs with an mechanism for the automatic lifting and lowering of patients and with a sliding seat will reduce the load on the lumbosacral region of the spine, prevent the onset of lumbosacral pain syndrome, facilitates work for the medical nurse and allows nurse to handle the patient on her own. The prevention of lumbosacral pain syndrome improves the quality of work of the nurse and extends the working life. Use of this type of wheelchair is justified in terms of cost-benefit analysis

The optimal design of school desks depending on the height and weight of students

Background: The subject of this research is the creation of an optimal school bench design with the aim of determining the most favorable posture of students while sitting, taking into account the relevant ergonometric and biomechanical characteristics of the human body. For the proposed model of the school bench which allows adjusting the different slopes of its surface, the corresponding computer model of the student and the table was first created, and then biomechanical and RULA analysis was performed in order to determine the maximum load in the lumbar part. Next, for each test subject of given weight, it was necessary to determine the amount of maximum load in lumbar zone L3/L4 for different slope angles and to determine the critical angles at which the maximum permissible load of 3400 N is reached. Methods: The analysis is performed on a total of 5 subjects of the same height (180 cm) and various weights (60, 70, 80, 90, 100 kg). The task is to determine at which weight and at what angle of the workbench with standard height will not exceed the permissible loads of the spine, specifically referring to the L4/L5 vertebrae whose stresses should not exceed 3400 N. The CATIA software package (Dassault Systèmes, Vélizy-Villacoublay, France) is used for the analysis. By knowing the anthropometric and work environment data with ergonomic design and analysis, the following analyzes were made: biomechanical analysis, rapid upper limb assessment (RULA) and carry analysis (an option from CATIA software). Results: The proposed school bench design allows for flexible adjustments to its worktop, that is, changing its tilt. This allows students of different body masses to have an optimal position at work that does not compromise their maximum permissible load in the L4/L5 spinal column (3400N). Conclusions: The proposed ergonomic design of the desk will result in students being adequately positioned during their activities at school with the minimal risk of permanent deviations and other health problems

Numerical simulation of hot forging process in production of axisymmetric automobile parts

The finite element method and the DEFORM software were used for the plastic metal flow prediction of ring shaped parts. Various parameters that affect the forging operation are the material characteristics like material strength, ductility, deformation rate, temperature sensitivity and frictional characteristics of the workpiece, preform design, die design and die material. Numerical simulation has been done for axisymmetric automobile parts. The procedure of numerical modeling contains all simulations phases like the movement of preform from inductor to the tool, placement and setting of preform piece inside the tool before the blow in order to get as good result as possible. These techniques are used to reduce the amount of input material for forgings, extend the lifetime of forging dies, and prevent defects in forged components

Biomechanical analysis of three-point shot in basketball

Background: A precise three-point shot (3S) is considered a key parameter of success in a basketball game, and therefore the factors that affect its success have always attracted the attention of researchers. Aim: The aim of this research was a biomechanical-mathematical analysis of 3S in basketball, in order to determine the key parameters for performing a 3S. Results: The research shows a model of shooting a basketball player from the central position of the shot with 6.75 m. The modeling led to the conclusion that the height of the throw, the speed and the angle of the throw of the ball have a positive and direct relationship with the angle at which the ball falls into the basket when it comes to a shot for three points. Conclusion: The height of the throw, the speed and the angle of the ball have a positive and direct relationship with the angle at which the ball hits the basket when it comes to a shot for three points. Anthropometric characteristics of the player, such as the length of the arm, and the height of the player, directly lead to a positive relationship with the throwing angle

Lumbar-load analysis of a soldier while carrying the heavy loads

Background: The aim of the article was to create an appropriate computer model based on the real status of the mortar operator's workplace and to analyze the workplace. After that, for any possible exceedances from the aspect of the organism's load and safety, the aim is to redesign the workplace and bring it within the limits of the permissible load, and therefore the required safety. The aim is also to identify the characteristic work movements performed by the soldier and to carry out an ergonomic analysis of the soldier's efforts and to propose appropriate improvements. Methods: The analysis is performed on a total of 20 soldiers, from which is determined an average model of the following characteristics: 180 cm in height and 85 kg in weight. The task is to take a mine from the shell containing the mines, then transfer it to the mortar and fill the mortar barrel. The weight of the 120 mm mortar grenade is 14.8 kg. The average soldier is 26 years old and his military exercise lasts 4 hours. The CATIA software package (Dassault Systèmes, Vélizy-Villacoublay, France) is used for analysis. By knowing the anthropometric and work environment data, with ergonomic design and analysis, the following analyses were made: biomechanical analysis, rapid upper limb assessment (RULA) and carry analysis (option from CATIA software). Results: The proposed modification of the position resulted in a decrease in the L4/L5 torque from 316 Nm to 154 Nm along with decreasing of the compression force on the L4/ L5 from 5779 N to 3038 N (the compression force allowed is 3400 N), and while the RULA analysis is from the red color position 1 (score 7; maximum load requiring rapid repositioning of such position), revised final score 4 made in yellow (a solution acceptable for this work place). Conclusions: By ergonomic analysis, obtained proposal will lead to less chance of injury, prevention of burn out syndrome, fewer chances of illness, decreasing the fatigue, greater safety, less energy spent and better preparedness for all necessary tasks

Influence of school backpacks on spinal column load in primary school students

Background: The problem of heavy school bags is a global problem recognized in many countries in Europe and the world, including in Bosnia and Herzegovina. In addition to poor posture habits, "sedentary lifestyles" and insufficient physical activity, school bags is one of the main causes of low back pain and deformity in pupils. The recommendation of the World Health Organization (WHO) is that the weight of the school bag should not exceed 10% of the student's weight. However, in practice these limitations are far from reality with the obvious problems caused by too heavy bags. The aim of the paper is to identify and analyze the backbone load caused by the overweight school backpacks in real school work conditions and eliminate them by creating new solutions that are in line with ergonomic and biomechanical principles, as well as the recommendation given by WHO. Methods: The research included first grade primary school students at the age of seven, including their parents. The research began by interviewing parents with relevant questions, as well as measuring the students’ height and weight and the weight of their school backpacks. The analysis was performed in CATIA v5 software package (Dassault Systèmes, Vélizy-Villacoublay, France) using its advanced biomechanical modules. By knowing the anthropometric and work environment data with ergonomic design and analysis, the biomechanical analysis, rapid upper limb assessment (RULA) and carry analysis were performed. Results: The conducted survey showed that 84% of students walk from home to school nineteen minutes on average and that 77% of them carry their school backpacks independently. Based on the measurements, it has been shown that, on average, the weight of the school backpacks is well above the WHO recommendation. A study conducted on a representative sample of students confirmed the relation between fatigue and spinal pain caused by carrying a heavy school bag. Computer analysis showed excessive loads on the spinal segment of L4/L5 that were outside the normal range of 3,400 N. Conclusions: A simulated computer analysis using RULA and biomechanical analysis with calculations of maximum loads in the lumbar segment of students found that school backpacks carried by students were too heavy for their age and well beyond the normal limits and WHO recommendations. The analysis showed that it is necessary to reduce the weight of the bag by about 30%

Modelling and identification of dynamic systems using modal and spectral data / by Senad A. Burak.

Bibliography: leaves 197-206.viii, 210 leaves : ill. ; 30 cm.The objective of this work is to study some new inverse problems related to mechanical systems, typical to the theory of vibration and engineering practice.Thesis (Ph.D.)--University of Adelaide,Dept. of Mechanical Engineering, 199