AHFE Open AccessAdvances in Physical Ergonomics and Human Factors: Part II
Editors: Tareq Ahram, Renliu Jang
Topics: Physical Ergonomics and Human Factors
Publication Date: 2018
ISBN: 978-1-4951-2105-0
DOI: 10.54941/ahfe100048
Articles
Ergonomic Supporting Unit for Invasive Surgery
Background: In health care industry, scientific studies and technological developments are implemented in daily use as soon as possible to save time for the diagnosis and the treatment of the patients. Where as the interest of the caregivers are neglected most of the time.Layout of the operating room and the ergonomic design of the equipment used during surgery should be advance in order to prevent disorders and long-term musculoskeletal illnesses among surgeons. The surgeons’ ‘ease of use’ is ignored most of the time until health problems start to arouse as occupational illness.With the development of technology, endovascular and laparoscopic procedures (minimally invasive surgery) are replacing the conventional open surgeries. Instruments used for laparoscopic surgery are longer in size than the ones used in open surgery. The visual interface is a monitor instead of the site of surgery. Surgeons work in awkward static postures. Lumbar region of the spine of surgeons is affected by the torque, which is caused by the departure angles of the joints of upper extremity especially when the arms are outstretched and unsupported.To evaluate and determine the problems of the working environment in the operation room, a survey is carried out on the basis of ergonomic design. Questionnaires searching for the causing factors of musculoskeletal injuries during operations are made with the surgeons. The surgeon-supporting unit was designed to support upper extremity of the surgeons in a seated position to increase their comfort.Methods: Photographs of the operation team are taken during surgery. Static postures of the surgeons are evaluated with model-based software called PCMAN. Angles of the body parts during procedures are found out and 3D mannequin of a surgeon is formed in solid works. The support is designed around the mannequin. Design vision of the support was to fallow the arm movements of the surgeon while supporting them. Prototype surgeon supporting unit was constructed and tested by ten surgeons. Two of the surgeons tested the supporting unit twice during surgeries.Results: Nine of participating surgeons preferred seated position and seven of them said that using arm support is comfortable. All of the participating surgeons indicated that the horizontal and vertical movements of the support were satisfactory. Eight participants said that vertical stability is satisfactory; four of them said that horizontal stability is satisfactory. Seven participants said that horizontal ease of use is satisfactory.Conclusion: Results of the study indicates that the surgeon should be able to immobilize the supporting unit at a desired horizontal position. Control of the vertical movement was by pedals. Since the surgeons are using other pedaled equipment during surgeries, the vertical movement should be controlled in another way to prevent confusions. Overall evaluation of the study shows that working at a seated position and supporting the arms reduce discomfort of the surgeons.
Semra Serdaroğlu Tigrel, Nigan Bayazıt
Open Access
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Conference Proceedings
Eye Movement Analysis on Observation Method “Mitate” of Urushi Craftspeople
Urushi crafts is one of the Japanese traditional crafts. If Urushi crafts works are broken, they can be used over and over again by repainting Urushi or sprinkling metallic powders. When they are repaired, their conditions, materials and techniques need to be understood in order to be repaired correctly. Expert Urushi craftspeople can gain an insight into these characteristics by the naked eye, and can repair correctly. In this study, it was aimed to examine the eye movement of the Urushi craftspeople when they looked at the Urushi crafts works. And then eye movements were measured for expert and non-expert Urushi craftspeople and students studying Urushi crafts technique. As the results, it was considered that the expert had more balanced look at each part of the work than the non-expert and students.
Atsushi Endo*, Chieko Narita*, Koji Kuroda**, Yuka Takai***, Akihiko Goto***, Yutaro Shimode****, Hiroyuki Hamada*
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Overall Car Seat Discomfort Onset during Long Duration Driving Trials
Mansfield et al. (2014) proposed a multi-factorial conceptual model for overall car seat discomfort that includes static, dynamic and temporal factors and suggests that overall car seat discomfort increases with time. Driving duration has been reported to significantly influence driver discomfort and long term evaluations of driver discomfort are necessary when assessing the performance of a car seat. This paper reports a laboratory study where 10 subjects (6 male and 4 female) conducted 140 minutes driving on a dynamic driving simulator and reported their discomfort every 10 minutes. It is observed that discomfort increases with time; however the rate of discomfort onset is shown to decrease with extended duration of driving (>70 minutes), and therefore it is observed that discomfort does not increase linearly across the 140 minute trial. It is concluded that drivers may alter their behaviour to cope with increased levels of discomfort as driving duration increases and suggests that future work should aim to investigate the theory that participants move in the seat with increasing frequency as overall car seat discomfort increases. Furthermore, future work should aim to validate the conceptual model proposed by Mansfield et al. (2014) against greatly extended driving duration and should aim to incorporate the change in rate of discomfort onset observed in this study when predicting long term driver discomfort.
George M Sammonds, Mike J Fray, Neil J Mansfield
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Automated Musculoskeletal Disorders Assessment Using OWAS and Kinect
Workers musculoskeletal occupational injury is closely related to worker's job status and posture. Short-term or long-term excessive exercise and poor posture may cause temporary or permanent musculoskeletal hazards, affect workers physical health. OWAS is a comomly used evaluation tool for working postures disorders assessment. It requires an ergonomics expert to evaluate through the musculoskeletal disorders risk table. Using OWAS evaluation system not only can provide injury prevention but also can calculate various influence of injury. However, this evaluation requires an expert to monitor an operator for a long period of time, which is tedious and high cost. This objective of this paper is to build an automated musculoskeletal disorders assessment system using the Microsoft Kinect with the OWAS system scuh that the related working postures disorders can be easily explored. The proposed system uses Kinect skeleton tracking system to collect worker’s skeleton information including head, hands, wrists, elbows, shoulders, trunk, hips, knees and foot (20 knots). By means of a self-developed algorithm, the system can automatically record, analyze, and assesse the joint positions and angles between joints such that the posture of a worker can be identified based on OWAS coding system. The proposed system was implemented using C# under Window 7 platform with Microsoft Kinect SDK. A set of experiments was conducted to verify and validate the Kinect skeleton tracking system and self-developed algorithms. The experimental results show that the proposed system effectively recorded and estimated the posture of workers such that manpower and resources are saved and the potential of job hazard can be explored.
Te-Hsiu Suna, Rong-He Linb, Mei-Lin Liub, Fang-Chih Tienb, Yi-Tsong Panc
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The Occlusion Method for Measuring Visual Demand at the IT-Based Driver’s Workplace
The standard ISO 16673 addresses the use of in-vehicle information systems (IVIS) and the measurement of the associated visual demand. The proposed measuring method investigates secondary tasks at the driver’s workplace in terms of their visual demand. The contributory factors and hence levers for prevention work are the complexity of the task, the usability of the man-machine interface (MMI) with its retroactive effects on task complexity, and device visibility (clear identification of symbols) and position. These factors are rendered measurable in their cumulative visual effect by the occlusion method so that valid and practical recommendations can be made.
Michael Bretschneider-Hagemes
Open Access
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Conference Proceedings
Analysis of Novice and Experienced Rice Farmer Grip Force and Arm Muscle Activity in a Plowing Task
A previous study observed significant differences in rice farmer exertion and fatigue potential based on levels of expertise in field plowing. The present study sought to identify arm and hand movement strategies of experienced farmers for reducing fatigue and minimizing injury potential. Twenty experienced farmers (>= 2 years of experience) and 10 novices were asked to perform eight replications of a simulated plowing task using a high-fidelity apparatus. Grip force and arm muscle activity levels were collected for the flexor digitorum superficialis (FDS), extensor digitorum (ED) and triceps. Comparisons were made on the fatigue rate of response measures and effectiveness of muscle use between experienced and novice participants. Results revealed experienced farmers to generate higher grip force and lower fatigue rates with the FDS muscle, as well as more effective use of ED muscles (higher grip/activity), as compared to novices. Experienced farmer strategy also involved balanced activity levels for agonist (FDS) and antagonist (ED) muscles. Novices were found to largely use ED muscles to generate grip force. Imbalance in agonist and antagonist muscles activity could lead to rough movement patterns and increased risk of muscle overuse. These findings may be useful for developing training for farmers to achieve effective muscle use and minimize risk of arm and hand injuries.
Manida Swangnetr, David Kaber
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Conference Proceedings
A Study on the Occupational Health & Safety Management System Integrated with Business Continuity Management System
Recently, incidents and disasters occurring in home as well as abroad influence whole industrial society not just limited in business places or districts. If safety management system of business is broken, then an incident occurs. This brings out a huge loss at the scene of an incident and other businesses. And then, delayed and passive reaction to this incident may be expanded to a national disaster. A state of emergency caused by these disasters threatens countries and public's safety in addition to company's loss, and it can encourage social and financial anxiety worldwide. If BCMS(Business Continuity Management System)’s, which has recently been adopted as a social safety system, is established in a general place of business, overlap and collision are inevitable in many sides. And it will make an overlapped organization that makes confusion in company by a cost of management. To avoid these overlap and collision, for making better OH&SMS (Occupational Health and Safety Management System), companies need to construct a unified business system after adding applicable requirements in business place. And then we can minimize confusions and burdens in company, and operate integrated system including BCMS. This study suggests using HSSMS (Health, Safety and Security Management System) which is KOSHA 18001 - nowadays many companies are used in KOREA - utilized by BCMS. If company adopts this HSSMS(Health, Safety and Security Management System), following positive effects can be expected.1) HSSMS makes it possible for company's OH&SMS to unify with BCM systems and to be continual improvement and operation.2) Because HSSMS makes OH&SMS communicate with national BCMS, it helps constructing and operating BCMS being cooperated by the public and civil sector.3) OH&SMS and BCMS make it easier to decrease accident rate, enhance working environment, increase productivity, hold a dominant position in internal and external market, preoccupy the appearance of global standard, and respond the voluntary restraints of market.
Chan-O Kim a, Young-Guk Kwon a, Se-Jung Oh b
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Conference Proceedings
Postures and Movements of Upper Arms and Upper Back During Box Handling in Real Setting
Considering the lack of studies assessing biomechanical exposure during manual material handling (MMH) in real work environment, the aims of this study are: (1) describing postures and movements of the upper back and upper arms during MMH performed in a regular workday in a real setting; (2) comparing postures and movements according to height level of the MMH; and (3) investigating the relationship between postures/movements and the workers’ experience. Fourteen workers (28.14 ± 6.73 years) from the distribution sector of an automotive factory were evaluated during four hours of their regular work. Three workers who presented more than five years performing MMH tasks were considered as expert (6.33 ± 0.57 years of experience in MMH tasks). Eleven workers were classified as novices (1.24 ± 0.78 years). Postures and movements of upper back and upper arms were measured using inclinometers. APDF percentiles (10th, 50th, and 90th) were obtained for angles and angular velocities. All data were descriptively analyzed and a one-way ANOVA was performed in order to compare biomechanical exposure during MMH tasks performed in three different, and most adopted, heights (floor, chest and shoulder levels). Pearson correlation test was applied to investigate the association between experience and biomechanical exposure variables. Alfa level was set at 0.05. In general, the descriptive analyses showed no expressive difference between expert and novice workers. Significant statistical differences in upper back and upper arms posture and movement among the three most frequent handling heights were found. Moreover, there was a positive and significant correlation between workers’ experience and humeral elevation. Despite the limited number of workers, we could evaluate what in fact happen in real settings. We believe that the evaluation of larger samples would demonstrate differences between expert and novice workers also in real settings, as we could observe a tendency of safer strategies among experienced workers. The challenge is finding larger groups of workers doing MMH tasks considering the lean production systems.
Helen Cristina Nogueira a, Francisco Locks a, Marylaine Costa b, José Hermosilla b, Ana Beatriz Oliveira a
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Prevalence of Lower Extremity Malaignment in Rice Farmers
Rice farming activities in Thailand are still based on manual work and human-machine interaction. Most tasks are involved awkward postures, repetitive motion, high force and prolonged work. Long-term exposure to ergonomics risks and lower extremity disorders can produce lower extremity malalignment, which has been reported to increase risk of lower extremity injury and disabilities. The objective of this study was to investigate the prevalence of lower extremity malalignment in rice farmers. A cross-sectional survey was conducted with 292 rice farmers in Khon- Kaen province, Thailand. Participants were required to have experience at least one year in rice cultivation process and have no current injury on back and lower extremity or any previous history that affected the lower extremity alignment. The measurement included pelvic angle, femoral antetorsion, quadriceps (Q) angle, tibiofemoral angle, genu recurvatum, tibial torsion, rearfoot angle and medial longitudinal arch angle. Results revealed the prevalence of lower extremity characteristics to be highest in foot pronation (20.89%), followed by knee valgus (18.49%), respectively. Other malalignment included external tibial torsion (11.64%), anterior pelvic tilt (10.96%), femoral antetorsion (6.85%), knee hyperextension (5.82%), and knee varus (3.43%). The findings indicated lower extremity malalignment to be common among Thai rice farmers, especially foot and knee malalignment. The knowledge gained from this study will be beneficial for healthcare providers in order to advise farmers on lower extremity malalignment prevention and self-management.
Usa Karukunchitab, Manida Swangnetrac, Rungthip Puntumetakulab, Wichai Eungpinichpongab, Alongkot Emasithib
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Effect of Backpack Carriage Position on Physiological Cost and Subjective Responses of University Students
The purpose of this study was to determine the effect that the position of a backpack has on physiological cost and perceptual responses of university students. Twelve male volunteers walked at a brisk pace along a half-mile indoor course that included level hallways, stairs, and ramps carrying books weighing 15% of their body weight in a backpack on upper back vs. lower back placement vs. no load condition. Average heart rate (HR) and subjective body discomfort ratings in neck, shoulder, upper back and lower back were significantly higher (p<.05) for carrying the backpack as compared to walking with no load. The peak HR was significantly higher (p<.05) for upper backpack position (122 bpm) compared to that for lower backpack position (117 bpm). Average HR, body discomfort ratings, and fatigue measures of bilateral trapezius muscles showed increasing trends from no load to lower backpack to upper backpack positions; however the increases were not statistically significant. The results indicated that wearing the backpack on upper back may impose additional physical stress on male university students.
Salil Joseph, Arijit Sengupta
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Identification of High-Intensity Physical Activities during Child Rearing Using a Triaxial Accelerometer
Child rearing is an important activity for parents or caregivers, but the workload involved in child rearing has not yet been quantitatively assessed to improve the works. This study measured the daily physical activity of three fathers and one mother by an activity meter which included a triaxial accelerometer, in terms of metabolic equivalents (METs) and the type of activity (locomotive or non-locomotive). Participant wore the activity meter around their chest from awakening in the morning to sleeping at night during child rearing and while working. They also manually recorded their activity during certain 30-minutes periods via a questionnaire. All the participants undertook the high-intensity activities (3.0-6.0 METs) while having meals, tidying, accompanying, playing, shopping, and moving with the children. The mother also undertook the high-intensity activity (3.0-4.7 METs) during housework and cooking. Activities for child rearing registered the same intensity as commuting or working, but these activities appeared intermittently. The results suggest that services such as child-care rooms in shopping centers or short-term care by caregivers at the parent’s home should be provided for parents and their children. These services will motivate parents to think that child rearing is positive and worthwhile.
Masato Takanokura, Kenji Ariizumi, Nozomu Imai, Seiko Taki, Tetsuo Yamada
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Physical Exercise Program to Control Musculoskeletal Symptoms Among Sewing Machine Workers of an Aircraft Maintenance Company
Sewing machine workers have high prevalence of WMSDs in neck-shoulder, wrists and lower back region. It is known that occupational physical exercises programs have positive benefits regarding complaints and absenteeism due to musculoskeletal symptoms. Therefore, the aims of this study were to evaluate ergonomic, musculoskeletal and psychosocial conditions of workers from an upholstery and sewing sector, and investigate the effectiveness of a physical exercise program applied at the occupational environment. Fifteen workers (44.5 ± 8.8 years old) took part of the study. Musculoskeletal symptoms were evaluated through the Nordic Musculoskeletal Questionnaire (NMQ), Roland–Morris Disability Questionnaire (RDQ) and a standardized physical examination. Psychosocial indicators were evaluated from the Job Content Questionnaire (JCQ) and Utrecht Work Engagement Scale (UWES), while the Ergonomic Workplace Analysis (EWA) protocol was applied to assess workplace conditions. The physical exercise program was applied twice a week for 30 minutes, during 12 weeks. It was composed by warm-up, strengthening and stretching exercises. A significant reduction on musculoskeletal symptoms were observed for wrists/hands and lumbar spine considering results from the NMQ, and for all body regions assessed through the physical examination, except for elbows. Moreover, psychosocial indicators have shown significant improvement. These benefits increase workability and promote better quality of life to the workers, and can be reproduced in other workplaces.
Januário LB, Moreira RFC, Barros FC, Oliveira AB
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Determination of Forces Required to Open Valves
The objectives of this study are: (1) to determine the effects of handwheel height and angle on valve-operators’ torque production; (2) to recommend maximum acceptable torque (MAT) limits for valve systems that will not exceed operators’ capabilities; and (3) to review and summarize the literature concerning the effects of handwheel height and angle on valve-operators. A total of 60 participants were recruited for this study, including 30 males and 30 females. The handwheel heights included knee, elbow, shoulder, and overhead levels. The handwheel angles included 0o, 45o, and 90o. At each height-angle combination, maximum isometric torque exertions on a handwheel were measured. MAT limits were computed using the 5th percentile torque strength values of the female participants. Depending on the height and angle of the handwheel, the average maximum torque exertions ranged from 51.6 Nm (found at overhead 0o) to 74.9 Nm (found at overhead 45o). The MAT limits ranged between 13.7 Nm and 24.1 Nm, depending on the height and angle of the handwheel. The results of similar studies in the literature and the current research are summarized and compared in one table.
Saif Al-Qaisia, Fereydoun Aghazadehb, Laura Ikumab
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Study on Kind Transfer Assistance Between Wheelchair and Bed In the Case of Eye Movement Analysis
As of October, 2012, the elderly make up 24.1% of the Japanese population. Japanese society is aging at one of the highest rates in the world. The number of recipients of nursing care is likely to increase dramatically in the near future. Due to a shortage of expert nursing staff, training caregivers for long-term care facilities has become a growing concern. To help speed the training process, we examined one of the processes where caregiver experience is most obvious: transferring patients between their bed and a wheelchair. To better understand the benefits of experience, we measured the nursing staff's eye movements during transfer, and found that expert caregivers' eyes moved more quickly than non-experts', which suggests that transfer assistance can be improved by instructing the caretakers to focus on specific parts of the patient's body.
Mikako Itoa, Atsushi Endob, Yuka Takaic, Takashi Yoshikawad, Akihiko Gotoc, Noriaki Kuwaharab
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Ergonomics of the Standing Smart: Increasing the Comfort of Standing Workers
The aim of our study is to increase the comfort of users at work by studying the balance and by minimizing the joint stresses. Studying the upright position, the adjusting of his segments to maintain the good balance and decreasing muscular problems are the main elements to highlight in order to improve the everyday (working) life of users. Based on the optimization of new materials, the project consists in validating prototypes destined to improve ergonomics at work and to optimize the comfort of users (new anti-fatigue mats Notrax®). Without mats our results showed a dysfunction balance of the worker which can cause pathologies or repetitiveness and other work constraining factors which can accelerate the process. The distribution of foot pressure obtained (30% and 70%) of the weight of the body is mainly on the right side. This imbalance is very harmful for the human body. With Mats we observed in working situations where people make small movements constantly, the anti-fatigue mats that we tested good properties that give a muscular-skeletal comfort in upright working positions. This can be verified by the constancy of the force evolution curve during the movement.
Redha Taïar a
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Effects of Load Carriage on Lumbopelvic Motor Control
Load carriage has become a concern in many industrialized countries and problems of musculoskeletal pain and stress on spinal structures due to load carriage have been widely reported. Various studies have been conducted to investigate the etiology of back pain due to load carriage. As people with low back pain exhibit abnormal spinal control, effects of load carriage on spinal control have been investigated in static upright stance. However, its effect on dynamic spinal control is not clear. In this study, the effects of load carriage on dynamic spinal control were investigated. Lumbopelvic movement control of 12 healthy female volunteers was quantified whilst performing a reaching task under four loading conditions, i.e. no load, carrying backpack of 5%, 10% and 15% body weight (BW). It was shown that lumbopelvic coordination was less in-phase and more variable during load carriage of 10% and 15%BW in forward reaching movement, suggesting greater alteration in spinal motor control at heavier weights. As abnormal movement strategies tend to increase the risk of spinal injury, pragmatic approaches should be considered to eradicate the adverse effect of heavy load carriage on spinal motor control.
Daniel HK Chow
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Study on the Appraisal System of Manual Work Efficiency
The biomechanics and physiology of the joints, muscles, sensors and nerves of the hand, as well as the manual work were analyzed in detail. In addition to 65 minor indexes, 5 major ones including the strength, fatigue, range of motion, tactility and dexterity were proposed in order to evaluate the manual work efficiency. Different approaches and facilities corresponding with varied indexes aiming to appraising the efficiency were designed and manufactured. With the aid of these apparatus, 26 subjects participated in the tests which were relative to 5 major and 47 minor indexes. Based on the experimental results, an optimal appraisal system integrating with some indexes employed in the work efficiency assess were presented. Also, the optimal efficiency appraisal system’s practicality was verified by the evaluation of heat resistant gloves.
Ding Li Yang Feng Li JingWen Yuan XiuGan
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Effectiveness of Evidence Based Ergonomic Interventions in a Manufacturing Facility
A large US northwest aluminum mill has been committed to combating the work-related musculoskeletal disorders (WMSDs) that the metals manufacturing industry faces by improving their working conditions and protecting the health of their workers. The mill formed an ergonomics team a few years ago, which received 2.5 days of applied production ergonomics training from researchers of the SHARP program. Several changes have been made since then by the ergonomics team. A few changes were made in conjunction with some of the lean process activities, which focused on reducing waste and improving productivity. The goals of the present study were to qualitatively and quantitatively evaluate the improvement changes, with regards to their impact on biomechanical loading that may cause WMSDs. While several production processes and jobs were evaluated, only the following improvements will be reported in the present paper: (1) loading and unloading treated aluminum plates in the vertical heat treat area, (2) changing paper rolls on the Striene machine, (3) some changes associated with lean manufacturing activities. Significant improvements in terms of biomechanical loading reduction were observed in these intervention projects.
Stephen Baoa, Han Kima, Barbara Silversteina, Ninica Howarda
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What are the Feelings of Operators about Physical and Psychosocial Ergonomic Risks? A Case Study in SCANIA Production Angers
Ergonomic improvement and prevention of musculoskeletal disorders still remain quite important among assembly manufacturing. Then, having the valid and precise evaluation for psychological and physical risk factors as well as musculoskeletal symptoms is the first step for ergonomic risk management. The aim of this study was to evaluate the operators’ feelings in regards to physical and mental workloads a long with musculoskeletal symptoms. Furthermore, the interview was done with all the people Friday afternoon and Monday morning to compare the perceived exertion force at the first day and the last day of week. This cross-sectional study was done in SCANIA production Angers. In this trucks assembly plant one sector was chosen and two different questionnaires including self reported and interview questionnaire were filled out. Self-reported questionnaire evaluated 130 ergonomics variables and interview questionnaire 27 variables. The latter was completed two times Friday afternoon and Monday morning. Our finding showed that Most of study population show pain in lower back, elbow and shoulder. The most observed risk factors were in shoulders, elbows and wrists. The prevalence of psychosocial factors were high among assembly operators as 78% reported low decision latitude. Perceived exertion force for whole body for high workload working day in Friday was more than Monday morning even the difference wasn’t significant. The results showed that in addition to physical ergonomic workloads, there are psychosocial risk factors among assemblers. Furthermore, the body region that were more affected by risk factors were reported as WMSDs symptoms.
Mohsen Zare a, Michel Croq b, Julie Bodin a, Elodie Cercier a, Yves Roquelaure a
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Suitable Interhandle Distance on a Roll Box Pallet during Turning Task
Roll box pallets (RBPs) are manual material-handling equipment with four swivel wheels, used in Japan. Although they are widely used in almost all industries, many RBP-related operator accidents have occurred in the transportation industry, usually involving injuries to the hands or feet. To decrease the likelihood of hand injuries, it is important to install special handles situated toward the inside of the frames. This study aimed to determine a suitable RBP interhandle distance for turning movements. Six healthy young males were asked to move the RBP (height, 170 cm; depth, 80 cm; width, 60 cm) by 90° at a normal speed using handles with four different interhandle distances (40, 50, 60, and 80 cm) and two loading conditions (0 and 50 kg) for approximately 1.4 m. A three-axis accelerometer attached to the lower part of the RBP was used to measure motion. Then maximum combined values of the longitudinal and lateral directions (horizontal plane) and maximum upward values were analyzed during the initial response phase. Operability was evaluated by the acceleration data, handling process duration, and subjective evaluation. Operating duration was approximately 5 s. It was longer for the 50-kg loading condition for all interhandle distances, and significant differences between interhandle distances were not observed with both loads; however, the duration tended to be shorter with wider interhandle distances in the 50-kg loading condition. Subjective evaluation ratings were similar in RBP movement durations. The maximal acceleration on the horizontal plane showed varied with different interhandle distances, probably because horizontal acceleration tends to affect RBP movement in tasks combining lateral movement and rotation. In contrast, maximum upward acceleration increased with increased loads, but was not affected by an increase in the interhandle distance. This indicates that the upward acceleration probably corresponded to the lifting of the handles while applying lateral force. The results suggest that a wider interhandle distance, e.g., 80 cm, would be suitable for RBP movements, including lateral movement and rotation.
Akihiro Ohnishia, Masato Takanokurab, Atsushi Sugamaa
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Anthropometry of Indian Hill Women for Development of Agricultural Implements
Anthropometry deals with the measurements of physical properties which are essentials for designing any tools or equipments. For designing ergonomically sound women friendly technology and assessment of nutritional status anthropometry has the pivotal role. In the present study anthropometric measurements of 45 body dimensions of women and nutrition related measurements of body type were documented from farm women’s in hills of Uttarakhand. The aim of this study is to document the mean and percentile range of static and dynamic anthropometric measurements and to provide a comprehensive data for use by anthropologists, nutritionist and ergonomic practitioners who are engaged in designing and evaluating mechanized technologies for women. Various body dimensions in standing and sitting positions, reach measurements, determinants of body fat and Body Mass Index (BMI) were recorded for hill women working in the agricultural domain. Total 100 women extensively involved in agricultural operations were chosen for the study and reference data to specify the physical dimensions for enhancing operational ability, safety, and convenience and comfort were recorded. Skinfold thickness was measured at four sites i.e. biceps, triceps, subscapula and suprailiac. The data(mean ± Standard Deviation) in centimeters pertaining to stature 149.5 ± 9.04, Standing eye height 140.96 ± 6.89, Standing cervical height 129.33 ± 6.21, Standing shoulder height 123.63 ± 4.86 , Naval height 99.67 ± 2.02, Hip Breadth (Standing) 102.12 ± 6.11, Chest depth 85.80 ± 5.58, Chest Breadth 91.13 ± 4.48, Arm Span 57.66 ± 3.41, Elbow span 38.48 ± 2.22, Arm Length 50.12 ± 1.57, Ankle height 7.73 ± 1.01, Thigh Circumference 45.26 ± 4.28, Calf Circumference 29.54 ± 4.08, Sitting measurements, head and face, hand and foot anthropometry and reaches were incorporated. The range of biceps, triceps, subscapula and suprailiac for farm women varied between 3.9 to 8.1 mm, 6.2 to 10.8mm, 8.4 to 15.2 mm and 7.5 to 12.5 with the average of 5.9 ± 0.9 mm, 8.08 ± 1.8 mm, 12.75 ± 1.6 mm, 10.5 ± 3.5 mm respectively. It was found that body density of subjects was ranged from 1.03 to 1.06, with mean of 1.04 ± 0.003 and percent body fat was 24.5 ± 1.4. The subjects were classified into categories of chronic energy deficient, normal and obese on the basis of Body Mass Index. It was found that 46 percent were undernourished, 33.3 percent women were normal, 18 percent low normal and only 1.6 percent overweight.
Pratibha Joshi, Renu Jethi, Nirmal Chandra, M.L.Roy, Atheequlla G.A, H.L.Kharbirkar
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Effects of Force and Repetition on Inflammation due to Eccentric Muscle Contractions
Recent evidence strongly suggests that force and repetition interact in a consistent manner to affect musculoskeletal disorder (MSD) risk, likely due to an underlying fatigue failure process in affected tissues. This pilot study evaluated whether a force-repetition interaction was present with respect to inflammatory responses of elbow flexor muscles after eccentric exercise. 24 subjects performed eccentric contractions with 6 assigned to each of the following groups: low-force, low-repetition (LFLR), low-force, high-repetition (LFHR), high-force, low-repetition (HFLR) or high-force, high-repetition (HFHR). High- and low-force eccentric contractions were set 120% and 60% of maximum isometric capacity, respectively. Low and high repetition rates were defined as two and eight repetitions/set. A baseline magnetic resonance image (MRI) was taken of their non-dominant arm prior to the eccentric exercise, as were relaxed elbow angle and maximum isometric strength. Dependent measures included MRI data on edema in the muscle (day 2 versus day 0), and relaxed elbow flexion angle and isometric strength (obtained days 0, 1, 2, 4, and 8 post-exercise). Significant force-repetition interactions were found for relaxed elbow angle at days 2 and 4 post-exercise (p < 0.05), and for days 2 and 4 for isometric strength (p < 0.05). MRI data demonstrated a non-significant force-repetition interaction (p > 0.05), but a tendency towards the expected interaction pattern.
Sean Gallagher, Richard F. Sesek, Jerry Davis
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Design of Tablet Storybooks Adopting a “Universal Design for Learning” Approach to Assist Bilingual Learning
Prior studies have shown that information technology is effective for increasing children’s vocabularies and reading comprehension; however, its effects on bilingual or heritage language learning require further study. This article reports on a bilingual tablet storybook design using the Universal Design for Learning (UDL) approach. The electronic storybooks were written in two languages: Mandarin and Vietnamese. After the welcome page, the tablet storybooks include four parts: a story in Mandarin (including text and reading), a story in Vietnamese, Mandarin games, and Vietnamese games. The text contains frequently used vocabulary. The storybook apps provide the frequently used vocabulary with Mandarin and Vietnamese pronunciations and explanations (in picture, oral, and text forms). In the second part of the game, “Little Story Teller,” the tablet provides five different background pictures and the users select and arrange the objects and figures presented in the pictures. This study sheds light on the application of tablet storybooks to heritage language learning or bilingual learning. Tablet storybooks can serve as a supplement for bilingual or multilingual learning and encourage a learner-centered and self-directed mode of instruction.
Yu-Ching Yeh, Ming-Chung Chen, Hsiang-Ju Ho
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Conference Proceedings
Measurement of Subject-Specific Local Muscle Fatigability
Cumulative muscle fatigue is one of the potential reasons leading to musculoskeletal disorders, and individual differences also result in different muscle fatigue progressions among workers while completing the same physical operation. Determination of subject-specific muscle fatigability could help the assignment of work-rest schedule individually, and further reduce musculoskeletal disorders. In this paper, the subject-specific fatigability is defined, and the features of subject-specific fatigability are proposed. According to the definition, a muscle fatigue model based approach is proposed and compared with conventional methods used to demonstrate fatigability. A novel and efficient method to determine subject-specific fatigue rate is developed based a muscle fatigue model and preliminarily validated by comparing force decline data from the literature.
Liang Ma, Jing Chang
Open Access
Article
Conference Proceedings
Save the Musicians! The Ergonomics of the Drumming
Drumming is a highly repetitive and demanding physical art nearly played in all music styles. Drummers use both two hands and feet during playing. Due to this fact, the musicians in the drumming profession are facing the risks of developing musculoskeletal pain and injury in the hands, wrists, elbows, shoulders, ankles as well as low back and neck areas. Especially, wrists, ankles and back are the most risky parts. To reduce the risks involved and improve the drumming performance, the drummer´ workstation set up, instruments and the method of performing need to be evaluated and redesigned according to the ergonomics principles. In this pilot study, a sample of eight drummers are surveyed for bodily discomfort/pain and injury. Findings indicate that the seating posture of drumming is the most critical ergonomics related issue. Low back, neck, and shoulders as well as ankles and wrists are at risks due to the awkward and/or static joint postures. Following the survey results, the drummer´s workstation set up, instruments and performing methods are evaluated and recommendations are provided.
Mahmut Ekşioğlu, N. Kaan Öztürk, Orkun Şirin
Open Access
Article
Conference Proceedings
Foot Dynamic Model for Investigate Foot Motion During Walking
Understanding dynamic foot is essential for foot health, footwear design and construction. This study was designed to investigate foot deformation during walking. A pilot experiment using motion capture system was conducted to record the landmark motion. The data showed the foot motion including landmark trajectories and the foot changes with time. In addition, the relative landmark position was further analyzed. The result showed the changes of foot landmarks. Application of this study will be useful for modeling dynamic foot shape, foot evaluation and footwear design.
Qilong Feng, Ameersing Luximon*, Balasankar Ganesan, Chee Kooi Chan
Open Access
Article
Conference Proceedings
Influence of Parameters on Landmark Automatic Identification from Three Dimensional (3D) Data
Local feature extraction is one of the fundamental aspects of the Three Dimensional (3D) data process and thus is quite promising. In our previous study, an algorithm combining Spin Image (SI) with Hidden Markov Model (HMM), was developed and applied on a 200 people database to automatically identify facial landmarks from 3D face data. The purpose of this work is to evaluate the reliability and accuracy of facial landmark identification with different parameter combinations, i.e. Bin Size (BS) and Support Angle (SA). Bin Size can improve or reduce Identification Accuracy Rate (IAR) by its value. The mean value of IAR increases with the Bin Size until the size reaches 10, when IAR acquires its maximum value 100% and remains constant before the Bin Size reaches 65. After that, IAR dropped with the increase of Bin Size, the velocity of the drop keeps increasing. Support Angle influences IAR positively. Support Angle starts to function at the value of 10 degrees, then, IAR increases with it until it reaches the degree of 90, when IAR acquired and maintained a constant maximum value of 100%. There are still several aspects need to be further studied such as efficiency and robustness. Moreover, using our method to identify landmarks on other human body segments is worth more investigation.
Jingchen. Liu, Le. Zhang, Xiao. Chen, Jianwei. Niu, *
Open Access
Article
Conference Proceedings
The Heuristic Evaluation Methodology of the Smartphone Operating System on the User preferences and Satisfaction of the Security System
The aim of this study is to study the smartphone operating system on the user preferences and satisfactions using selected heuristic usability method. In the security operating systems, the first layer of security within a smartphone is at the level of the operating system. Beyond the usual roles of the security operating system on a smartphone, it must also establish the protocols for introducing external applications and data without introducing risk. The security operating system contains important incidents which have greatly influenced development of smartphone security and of their importance today. There has been a leaking of personal information from a major portal site by the hackers. The selected usability principles are classified systematically using paired t-test (two aged groups) selected by Duncan’s Multiple Range Test and Principle Components Analysis (PCA) using Factor Analysis. The results are as follows: 25 usability principles for the operating system on the user preferences and satisfaction of the security system are categorized into four groups. According to their correlations and we named them respectively, users' preference and awareness of smartphone security operating system were significantly statistical different between Adolescence group and Senior-age group (***p< .001).
Ryang-Hee Kim, Young-Guk Kwon
Open Access
Article
Conference Proceedings
Modeling Peripheral Muscle Fatigue Using a Variable Recovery Rate
Muscle fatigue is a transient and reversible decrease in performance capacity after a period of physical exertion. A variety of approaches have been applied to model muscle fatigue. Recently a theoretical, phenomenal parameter-based model (Liu-Xia model) was proposed with the capability of predicting fatigue for tasks of any force-time history. The Liu-Xia model has two parameters F and R that define the fatigue and recovery behavior, respectively. Previously, F and R were treated as constant in model validation. In the current study, R is redefined as a function of exertion level in attempt to reflect the effect of muscle contraction on blood flow. The purpose is to examine if an R varying with exertion level can improve model prediction for low intensity, static and intermittent tasks. Particularly, R is modeled as a step-wise function of three regions: 0-10% maximum voluntary contraction (MVC), no occlusion; 10-50% MVC, 0-100% occlusion, assuming a linear relationship in the region; and 51-100%, full occlusion. The results suggest that an R varying with exertion level may serve as a viable way to improve model performance, dependent on a better modeling of the relationship between muscle contraction and blood flow.
Ting Xia
Open Access
Article
Conference Proceedings
Study on Astronauts’ Workload of Typical Tasks in Orbit
In order to arrange astronauts’ long-term working properly in the space station in the future, this study evaluated the workload of astronauts’ typical tasks in the Shenzhou-10 spacecraft. The seven tasks were selected as typical tasks including replacing the floor, assembling a dynamometer on a bike, connecting the pipeline of the condensed water for sampling test, pulmonary function tests after exercise, tests of oxygen producing with electrolysis, and manual-control rendezvous and docking. Through subjective measurement instrument modified NASA-TLX, the results indicated that astronauts’ workload of replacing the floor were the highest among the 7 tasks. And then followed was the workload from pulmonary function tests after exercise and the tests of oxygen producing with electrolysis. The workload from the task b1, Y1 was relative low. Although the task J1 was more complex and difficult, the astronauts’ workload was not high.
Li Wang, Gaoxiang Wang, Weifen Huang, Changhua Jiang, YuLin Xu
Open Access
Article
Conference Proceedings
Grip Force Simulations Using an Instrumented Cadaver Forearm
Forceful tendon exertions while gripping hand tools may be one of the factors leading to the development of work-related musculoskeletal disorders (WRSMDs). Estimated tendon forces from biomechanical hand models are unreliable and need to be validated. A novel neuromuscular grip simulator using a cadaver forearm was developed consisting of 1) an aluminum frame supporting the specimen, 2) a motion-delivery unit with stepper motors applying force to the FDP and FDS tendons, 3) a data acquisition unit for force transducers, 4) a camera system measuring finger joint angles, and 5) an operating system to control the complete simulator. Of special necessity were an adjustable fixation system, the Wristjack and the use of freeze clamps with liquid nitrogen to insure a tight bond between the slippery tendons and the force delivery system. Key experimental factors varied were five different diameter handles and the ratio of FDP/FDS tendon forces. The results on two specimens showed an inverse relationship of handle size and grip force, with the smallest handle size of 30 mm being best. A 3:2 ratio (40% FDS) provided the best efficiency and the largest gripping. Internal tendon averaged 6.2 times the external forces,matching the biomechanical model predictions of Kong, 2004. 72% of the power grip was concentrated on the distal phalanges. Overall, this novel simulator served well for understanding internal tendon forces.
Andris Freivalds, Shihyun Park, Joonho Changa, Neil Sharkeyb
Open Access
Article
Conference Proceedings
3D Functional Foot
The human foot is a complex biomechanical structure, which is consist of 26 bones, numerous muscles, ligaments, joints, nerves, arteries, veins and other soft tissues, is contributing the overall shape of the foot, and is mainly helping to bear the entire body weight, and static and dynamic motions of the foot. The foot has various dynamic motions such as dorsiflexion, plantar flexion, inversion, and eversion, abduction and adduction. The foot shape, structure, functions and motions will vary from one person to another person due to its own morphological structure. A footwear designer is necessary to know about these structures and functions of the foot to design and construct the footwear with comfort and fit. Conventional methods such as anthropometers, calipers, and tapes are used to get the anthropometric data to design the custom-made footwear. Recently, 3D scanning of the foot has been used to get the accurate anthropometric measurement foot data to design the good-fitting footwear. However, there are very few studies reported about Kinect for foot measurement. It is difficult to predict the changes of the foot inner structures during the various functional position of the foot. Therefore, this study tries to develop the 3D functional foot model with using different high heel position. It also considers the effect of land marking error. A result of this study is essential for the design of better fitting and comfortable footwear.
Luximon Ameersing a, Ganesan Balasankara, KaiWei Zhao a, Lap Ki Chanb
Open Access
Article
Conference Proceedings
Hand Anthropometry of Young Chinese Males Aged 18~35 Years Old
To evaluate the hand form of young Chinese male, an anthropometry survey was carried out in China from 2010 to 2011, and 9812 young Chinese men were measured with two-dimensional color graphs method and three-dimensional scanning technology. The differences exist in young Chinese male from different regions of China were studied by the hand index. The mean and standard deviation of each dimension of young Chinese male are summarized in tables and compared with those of other populations (Jordanian, Mexicans and Vietnamese). The results show that the seven geographical areas of China could be divided into three groups based on the different hand form types, and there are also significant difference in hand dimensions between young Chinese male and other nationalities.
Zheng Xiaohui a*, Ding Songtaoa, Zhang Xuezh i a, Fang Hea, Liu Taijieb, Wang Chunyu a
Open Access
Article
Conference Proceedings
Methodology of Physical Load Risk Assessment in Latvia
Occupational safety and health have a considerable value for employees and employers in Latvia. Despite the fact that modern production systems involve highly specialized and complex machinery, there are many human activities including manual tasks that have not been automated due to flexibility requirements. Physical overloading is caused, for example, by lifting or pushing heavy objects, daily use of vibratory tools or prolonged work while bending over. Insufficient physical load (lack of activities) is caused, for example, by prolonged sedentary work without periodic breaks for movement. The importance of psycho-emotional factors, including stress at work, should also be taken into account here. Musculoskeletal complaints are responsible for one-third of the reported cases of absenteeism and disability. Therefore, physical load forms the core of the problem, and is one of the main factors hindering sustained healthy, productive work, and wellbeing. This calls for the development of practical exposure assessment tools, particularly for health and safety practitioners, to quickly assess an exposure to ergonomic risks. The knowledge of the risk and corresponding risk assessment methods are aim of investigation and provide basis for the formulation and implementation of preventive measures. The road building workers, textile sewers and cutters, as well as fire-fighters-rescuers, who are employed in a wide range of tasks, were used as an example of ergonomic risk analysis.Several tools for description and assessment of ergonomic risks applying subjective, mathematical and experimental (objective) methods were used. The chosen tools and technique are: Extended Nordic Musculoskeletal Questionnaire (NMQ-E); KIM (exposure scores for pushing/pulling, carrying), QEC (exposure levels for main body regions), OWAS (time sampling for body postures and force), RULA (categorization of upper limb postures and force with action levels), MAC (manual handling assessment charts), NIOSH (lifting equations, biomechanical load limits), SI (the strain index), workload energy expenditure (WEE), heart rate monitoring (HRM), myotonometry (MYO), NASA-TLX (mental and physical workload interaction/task load index), WAI (work ability index). The chosen methods have been categorized under four main headings: 1) self-reports from workers, 2) observation methods, 3) mathematical methods, 4) direct measurement of exposure variables at work.Analysing these methods it was established that KIM, QEC, NIOSH, OWAS, WAI and HRM are more suitable for quick assessment of the ergonomic risks at work, while the RULA, WEE and MYO are more complicated for quick assessment. It was found that employee's subjective point of view on workload does not always coincide with the objective measurement results. It was concluded that the physical load assessment methods, analysed in this study, are successfully introduced in Latvia, and preventive measures, such as medical hypnotherapy, including cognitive hypnotherapy and self-hypnosis training sessions, are effective methods to decrease composite chronic pain intensity, as well as to decrease psychogenic tension and muscle fatigue, and to increase the life quality.
Valdis Kalkis, Zenija Roja, Henrijs Kalkis
Open Access
Article
Conference Proceedings
Impact of Physical Load on Workability of Social Caregivers
The contemporary changing labour market has promoted health problems caused by ergonomic load at work. In Latvia, similarly to other places in the world, within the recent 10 years number of work related muscular sceletal disorders (WRMSD) in the structure of occupational diseases has grown rapidly, and according to data from the State Labour Inspection, in 2012 these diseases comprised 60% of the total number of primary cases of occupational diseases. Employees in Latvia report about high physical workload and rapidly increasing psychoemotional strain at the workplaces. In the branch of social care WRMSD are extremely significant for younger and elderly employees. A social caregiver’s duty requires frequent manual lifting and awkward postures that makes severe burden for the waist. Low back pain is prevalent in care staffs with long-term experience. Increasing number of the elderly and severe disability of workers in social care intensifies the work load. Aim of the study is to investigate the effect of the physical load on adult and children caregivers’ workability, to work out preventive measures for reduction of ergonomic load and improvement of workability. The several tools to describe and assess physical load using subjective and experimental (objective) methods were used. Chosen tools and technique are: KIM key item method (assessment of the manual handling of heavy loads), HRM heart rate monitoring (assessment of work heaviness degree depending on workers physical activity), RPE the rating of perceived exertion, NIOSH lifting equation, and WAI workability index (assessment employees’ existing work capacity and forecast for the near future). It was stated that accordingly to results of HRM data (energy consumption) work hardness categories varies from category II (moderate work) for children caregivers to category III (hard work) for adult caregivers. It coincides with the subjective risk assessment methods. It was concluded that physical workload insignificantly impact workability of social caregivers
Zenija Roja, Valdis Kalkis, Henrijs Kalkis, Inara Roja, Janis Dundurs
Open Access
Article
Conference Proceedings
ErgoCapture – A Motion Capture Based Ergonomics Risk Assessment Tool
In the reduction of the work-related musculoskeletal disorders risk assessment tools have a central role. Although plenty of ergonomic risk assessment tool is availably their application is limited due to the inhomogeneity of the work, the difficulty of the selection of the proper assessment tool, the difficulty of the measurement of forces, joint angles and movement speed and the difficulty in the determination of risk modifying factors like vibration and heat.According to the EN 1005 standard the Composite Ergonomics Risk Assessment includes posture, force extension, manual handling and repetitive movements analysis, and in addition a subjective fatigue assessment. Since the Composite Ergonomics Risk Assessment (CERA) is based on the direct wMSD risk factors, the pages reflect to the posture and movement of the user and the evaluation of the working environment. The ErgoCapture system not only makes the risk assessment more precise and easy, but also opens possibilities to eliminate some general limitations of the ergonomic risk assessment methodology. In this paper some findings of a research and development process of a 3D camera based ergonomic risk assessment tool is presented. The report includes the data acquisition environment, the data analysis framework, and the perspectives of the underlying risk monitor approach. A motion capture technology based human posture analysis is presented, where nearest-neighbor analysis was used for data processing.
Gyula Szabó
Open Access
Article
Conference Proceedings
Work-Related Musculoskeletal Disorders and Prevention Among Home Healthcare Workers
Work-related musculoskeletal disorders are common and costly, particularly among home healthcare workers. These workers are a particularly interesting occupational group because of growth of the home healthcare industry and specific patient transfer exposures. This cross-sectional study of 883 home healthcare workers from 17 agencies evaluated self-reported personal and occupational factors related to 1-year period prevalence of neck pain. One-year prevalence odds ratios (PORs) were calculated by separately comparing WMSDs in aides and nurses to office workers/therapists. Multiple logistic regression models were constructed for WMSDs. For neck pain the potential confounders included in the logistic regression models were: age, gender, smoking history (calculated in pack years), body mass index (BMI), time spent performing aerobic exercises, personal psychosocial factors, work related psychosocial factors, miles traveled in an automobile during an average day, and the degree to which the HHCW felt rushed or hurried traveling from patient to patient. Many occupational and non-occupational factors were statistically significantly related to 1-year period prevalence of neck pain with prevalence odds ratios for home healthcare aides at 1.99 after adjustment for above factors. Nurses had higher statistically significant risk estimates at 2.17. Both home healthcare aides and nurses are at increased risk for neck pain.
Arun Garg a, Matthew S. Thieseb, Jay Kapelluscha, Kurt T. Hegmannb
Open Access
Article
Conference Proceedings
Investigation of the Effect of Individual Metabolic Differences on Workers Musculoskeletal Disorders
Evidence that workers have suffered from Musculoskeletal disorders (MSDs) has been noted as far back as 1713, though was known by different names, e.g. writer’s cramp, repetitive strain injury (RSI). These days, students and office workers, who use computer and mobile phones are suffering from it along with process and factory workers. Every year millions of workers are suffering from MSDs. Low productivity, workers’ compensation and other costs due to MSDs are costing billions of dollars every year to employers and governments. Some workers are susceptible to one type of MSDs but not others, despite performing the same repetitive work. This has surprised management and researchers. Researchers have not considered workers’ metabolic types in analysing their research, although correlation between health problems, repetitive work and metabolic types of the workers was reported in 1875. Three metabolic types: ectomorph, mesomorph and endomorph have distinct physical, physiological and psychological traits. The purpose of this research is to find the reasons why some workers are susceptible to one type of MSDs and others are not. By understanding that, it will be possible to develop a strategy to prevent MSDs by studying input, throughput and output. Metabolic types explain why some workers are susceptible to one type of MSDs and others are not, despite performing the same work.
Keshaba Nanda Baidya
Open Access
Article
Conference Proceedings
Psychophysical Responses of Waste Workers in Lifting Tasks at Two Different Levels
Manual Material Handling (MMH) is one of the key problems related to musculoskeletal disorders at the occupational settings. It is essential to assess the risk related to these tasks. The psychophysical approach can be used to assess and redesign the MMH tasks. Following a psychophysical approach and bearing in mind the specific problem faced by waste workers in a Portuguese hospital, this work aimed to determine, the Maximum Acceptable Weight (MAW) for the tasks of BIOBOX’s lifting. Two different levels of BIOBOX’s were assessed based on workers’ usual tasks. The subjects were instructed to lift the box from the height of 110 cm and 174 cm (handling height) up to the height of 84 cm, the same height of the truck. Each set of experiments was conducted for 10 minutes. The heart rate was continuously monitored. At the end of each task, the MAW was achieved and subjects were requested to assess the Index of Perceived Exertion (IPE). The MAW determined at 110 cm and 174 cm was, respectively, 10.0 kg and 6.8 kg. The regions of the shoulders, arms and back were identified as presenting more pain during the tasks. The results show that workers are at risk of musculoskeletal disorders. Therefore, a strategy to reduce the risk related to these tasks is needed.
Felicidade Pacheco a, Matilde A. Rodrigues a, Pedro R. R. Monteirob
Open Access
Article
Conference Proceedings