scholarly journals Ergonomic Mechanical Design and Assessment of a Waist Assist Exoskeleton for Reducing Lumbar Loads During Lifting Task

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 463 ◽  
Author(s):  
Xu Yong ◽  
Zefeng Yan ◽  
Can Wang ◽  
Chao Wang ◽  
Nan Li ◽  
...  

The purpose of this study was to develop a wearable waist exoskeleton to provide back support for industrial workers during repetitive lifting tasks and to assess reductions in back muscular activity. The ergonomic mechanical structure is convenient to employ in different applications. The exoskeleton attaches to the wearer’s body with 4 straps, takes only 30 s to put the exoskeleton on without additional help, weighs just 5 kg and is easy to carry. The mechanical clutch can assist the wearer as needed. Inertia Measurement Unit (IMU) was used to detect wearers’ motion intention. Ten subjects participated in the trial. Lower back muscle integrated electromyography (IEMG) of the left and right lumbar erector spinae (LES), thoracic erector spinae (TES), latissimus dorsi (LD) were compared in symmetrical lifting for six different objects (0, 5, 10, 15, 20, 25 kg) under two conditions of with and without the exoskeleton. The exoskeleton significantly reduced the back muscular activity during repetitive lifting tasks. The average integrated electromyography reductions were 34.0%, 33.9% and 24.1% for LES, TES and LD respectively. The exoskeleton can reduce burden and the incidence of strain on lumbar muscles during long-term lifting work.

2014 ◽  
Vol 564 ◽  
pp. 644-649 ◽  
Author(s):  
Halim Isa ◽  
Rawaida ◽  
Seri Rahayu Kamat ◽  
A. Rohana ◽  
Adi Saptari ◽  
...  

In industries, manual lifting is commonly practiced even though mechanized material handling equipment are provided. Manual lifting is used to transport or move products and goods to a desired place.Improper lifting techniquescontribute to muscle fatigue and low back pain that can lead to work efficiency and low productivity.The objective of this study were to analyze muscle activity in the left and right Erector Spinae, and left and right Biceps Brachii of five female subjects while performing manual lifting taskwithdifferent load mass, lifting height and twist angle.The muscle activitywere measured and analyzed using surface electromyography (sEMG).This study found that the right Biceps Brachii, right and left Erector Spinae experienced fatigue while performingasymmetric lifting (twist angle = 90°) at lifting height of 75 cm and 140 cm with load mass of 5 kg and 10 kg. Meanwhile, the left Biceps Brachii experienced fatigue when the lifting task was set at lifting height of 75 cm, load mass of 5 kg and twist angle of 90°.The load mass and lifting height has a significant influence to Mean Power Frequency (MPF) for left Biceps Brachii, left and right Erector Spinae. This study concluded that reducing the load mass can increase the muscles performance which can extend the transition-to-fatigue stage in the left and right Biceps Brachii and Erector Spinae.


2020 ◽  
Vol 21 (2) ◽  
pp. 164-176
Author(s):  
Radin Zaid Radin Umar ◽  
Fatin Ayuni Mohd Azli Lee ◽  
Muhammad Naqiuddin Khafiz ◽  
Nadiah Ahmad ◽  
Nazreen Abdullasim

Manual material transfer tasks are common in occupational settings. Repetitive lifting tasks usually involve twisting and bending which are associated with occupational lower back injuries. One of the approaches to reduce bending and twisting is to separate the distance between lifting origin and destination, which will encourage lifters to step and turn entire bodies. However, adding lifting distances is likely to affect space usages and requirements. A study was conducted to investigate how the transfer distances influence space usage during the lifting task. Raw data of hip and hand wrists motion of 26 male subjects during transfer in 4 different distances were captured using X-Sens motion capture system. MVN Studio software was used to process and extract positional data. Tabulated space mapping revealed limited hip movement and semicircular shaped hand motions for short transfer distances. The pattern changes into a more stretched-curve shape as the distance increases. Overall, it was observed that shorter transfer distance caused participants to adopt more twisting and less bending postures, while further transfer distances resulted in more bending and less twisting. This study may provide industrial practitioners with information to design a space requirement for manual material transfer tasks. ABSTRAK: Kerja-kerja pemindahan barang secara manual adalah biasa dalam persekitaran kerja. Kerja-kerja mengangkat barang yang kebiasaannya melibatkan badan membengkok dan berpusing boleh menyebabkan kecederaan tulang belakang. Salah satu cara bagi mengurangkan risiko ini adalah dengan memisahkan jarak antara tempat asal dan tempat tuju pemindahan barang. Pemindah barang digalakkan untuk melangkah dan memusingkan seluruh badan. Namun, cara ini menyebabkan penggunaan ruang yang banyak. Satu kajian telah dijalankan bagi mengkaji bagaimana jarak pemindahan barang mempengaruhi penggunaan ruang ketika kerja-kerja pemindahan. Data asal pergerakan pinggul dan pergelangan tangan daripada 26 subjek lelaki ketika pemindahan barang pada 4 jarak berbeza diperolehi menggunakan sistem rakaman gerakan X-Sens. Perisian MVN Studio digunakan bagi memproses dan mengekstrak data ini. Ruang pemetaan berjadual mendedahkan pergerakan pinggul yang terhad dan pergerakan tangan berbentuk separa bulat pada jarak pemindahan terdekat. Corak ini berubah kepada bentuk lengkung memanjang apabila jarak bertambah. Keseluruhannya, jarak pindahan yang kurang menyebabkan para peserta lebih terdedah kepada postur memusingkan badan berbanding membengkok, sementara jarak yang jauh menyebabkan peserta lebih membengkok berbanding memusingkan badan. Kajian ini memberikan maklumat untuk penggiat industri mereka cipta keperluan ruang bagi kerja-kerja pemindahan barang secara manual.


2020 ◽  
Vol 20 (Special1) ◽  
pp. 255-259
Author(s):  
Nur Athirah D ◽  
Karmegam K ◽  
Irniza R ◽  
Shamsul Bahri MT ◽  
Vivien H ◽  
...  

Discomfort due to riding a motorcycle is an issue that need to be addressed as it has long-term effects of musculoskeletal disorders on motorcyclists especially among occupational motorcyclist. Thus, this study was conducted to analyse the rating of muscle discomfort and correlation with the risk factors among traffic police riders. A cross-sectional study was carried out among 137 male traffic police riders (high-powered motorcycle) with the age between 20 to 39 years old. The 100-mm visual analogue scale questionnaire included ratings of perceived discomfort scales for 20 specific body regions was used in the study. The results indicate that the lower back (left and right) were the highest mean of discomfort which were 56.6 mm and 55.9 mm respectively. This followed with right (48.5±36.2 mm) and left (48.4±30.3 mm) upper back, and right hand (47.0±33.0 mm). The mean of overall discomfort ratings for all regions were more than 20 mm.  Besides, there is a strong positive significant correlation between duration of ridings (hours) and overall discomfort ratings (p<0.01, r=0.785) and moderate positive correlation between year of traffic police motorcycle riding experience and overall discomfort ratings (p<0.01, r=0.410). As a conclusion, cumulative riding hours, riding experience and no support of the back area of the body in motorcycle seat, are the most concern in this study as this are the contributing factors to the muscle discomfort among traffic police riders while riding high-powered motorcycle. Thus, this study suggested an additional feature is needed in current motorcycle design in order to enhance comforts of traffic police riders. Also, it will improve the condition of traffic police riders’ discomfort and indirectly also improve their work and health performance as well as productivity.


2017 ◽  
Vol 2 (1) ◽  
pp. 21
Author(s):  
Tirthankar Chatterjee ◽  
Sohini Paul ◽  
Anilendu Pramanik ◽  
Madhusudan Pal ◽  
Dhurjati Majumdar

<p>Soldiers of Indian Army need to carry moderate to heavy load in complex terrain conditions as their routine activity, which may prove to be highly tiring for leg and back muscles. Soldiers’ regular movement at hilly area was simulated in a study consisting of a continuous uphill (UH) and downhill (DH) load carriage task to monitor state of fatigue at back and lower limb muscles. Twelve Indian soldiers walked at a fixed speed on five UH and five DH gradients with three loads (0, 10.7 kg and 21.4 kg). Electromyographic (EMG) recording was carried out throughout the experimentation on four groups of muscles- left and right Erector spinae (ESR and ESL), Vastus medialis (VMR and VML), Gastrocnemius medialis (GMR and GML), and Soleus (SOR and SOL) muscles. Median frequency (MDF) responses of tested muscles were derived from raw (EMG) data. Higher level of muscle fatigue was observed at highest UH inclination as the MDF response in GMR, GML and VMR was lowest at this point. The MDF response were found to be lower at DH gradients as the physical demand of that stage is less than the UH gradients.</p>


1988 ◽  
Vol 4 (2) ◽  
pp. 156-165 ◽  
Author(s):  
Bart Van Gheluwe ◽  
Paul Huybrechts ◽  
Erik Deporte

This study evaluates the action of 20 selected arm and torso muscles. The subjects were 19 windsurfers of different skill levels. Muscular activity was recorded electromyographically, using surface electrodes. The subjects were standing on a specially devised windsurf simulator in order to keep the different surf postures as standardized as possible. Through two-way ANOVA techniques, the electromyographic activity relative to its maximal isometric value was compared for different muscles, surf postures, and skill levels. Also, differences between the left and right sides of the body were investigated. From the results, the following may be concluded: (a) As all muscles display rather low activity (an average of less than 20% of their maximal isometric values), windsurfing does not seem very demanding of muscular force. (b) The M. flexor carpi radialis, together with the M. erector spinae, tend to exhibit higher levels of activity for beginners, which suggests, respectively, a more rigid grip on the wishbone and stronger low back muscle activation in order to keep a correct posture, (c) Left–right asymmetries mainly occur for symmetrical body postures, especially for the M. flexor carpi radialis and the M. erector spinae. As for the M. trapezius (pars superior), experienced surfers tend to display a dominant right asymmetry, (d) Muscle activity does not exhibit significantly different values for various surf postures. However, typical deviating postures, as observed in beginners, may induce higher levels of muscle activation.


Author(s):  
Nathan Poon ◽  
Logan van Engelhoven ◽  
Homayoon Kazerooni ◽  
Carisa Harris

Although the effect of wearing a back-support exoskeleton during lifting has been demonstrated to reduce overall muscle activation, less is known about how wearing exoskeletons affect muscular fatigue and oxygen consumption. The purpose of this study is to evaluate the effect of wearing a back-support exoskeleton (backX) on muscle fatigue during repetitive lifting by assessing whether wearing backX increases endurance time relative to lifting unassisted. A secondary objective of this study is to quantify changes in oxygen consumption rate while performing a repetitive lifting task with and without backX to address a common industry concern. The UC Ergonomics Lab evaluated backX on twelve male subjects by measuring bilateral muscle activity of the erector spinae and oxygen consumption rate. Summary measures of muscle activity for 50 and 90 percent of the repetitive lifting session were used to characterize peak and mean muscle activity. Oxygen consumption rate was collected continuously during the repetitive lifting session. Compared to the unassisted condition, wearing backX reduced peak lumbar erector spinae activation by 16.5% and 21.8% (p < 0.05). The time subjects could hold a back-straining posture after the repetitive lifting session increased by 52% after wearing backX during the lifting task. The was no significant negative change in oxygen consumption rate. This study confirms that wearing a backX reduces muscle activation in the lower back for this specific dynamic lifting task. Additionally, we find that wearing a backX may reduce the risk of low back injuries by reducing muscle activity and increasing endurance time to fatigue


2005 ◽  
Vol 4 (3) ◽  
pp. 185-197
Author(s):  
Kamal Kothiyal ◽  
Tai Wai Yuen

This study presents the results of an evaluation of a patient handling aid commonly used for transferring patients from bed to toilet or other type of chairs. The results of the study showed that use of the patient handling aid (sling) increased the rate of perceived exertion at the lower back and the shoulder. Investigation of the muscular activity using electromyography in the shoulder and the lower back regions revealed that there was significant increase in the erector spinae activity in the lower back region. The increase in the back strain in the sling transfer was related to the increase in lumbar flexion resulting from the relatively smaller size of the sling. Trapezius muscle on the other hand did not indicate any difference in activity. The results of this study indicate that for positive outcomes there is a need for ergonomic evaluation of the sling and the postures adopted by the patient handler while transferring the patient with the sling.


2021 ◽  
Author(s):  
Betty Thomas ◽  
Shyam Krishnan K ◽  
Ashish John Prabhakar ◽  
Megha M. Nayak ◽  
Charu Eapen

Abstract Background: An on body personal lift assist device (OBPLAD) is a non-motorized, passive device in which the elastic elements act as an external muscle power generator to assist lifting thereby offloading the trunk muscles. Though there is enough evidence for the use of OBPLAD generated through laboratory studies, we found a scarcity of evidence on the use of OBPLAD in real-life work settings, especially in the Indian population. This study investigates the effect of the Jaipur belt, an OBPLAD, on trunk muscle fatiguability while performing repetitive lifting task in manual material handlers. Methods:70 subjects engaged in manual material handling were recruited from industries in and around Mangalore, Karnataka in this non-randomized single group trial. Subjects were made to perform a repetitive lifting task over a period of 15 minutes with and without an OBPLAD. Electromyographic data were recorded from rectus abdominis, transverse abdominis, quadratus lumborum, and erector spinae from either side of the body, and the onset of fatigue was deduced from the changes in electromyographic parameters. Results: We found a delay in the onset of fatigue in all the muscle groups studied while the lift was performed wearing the Jaipur belt. However, the findings were statistically significant only for right erector spinae, right rectus abdominis, left transverse abdominis, and left quadratus lumborum. It was found also that number of repetitions as well as time for which a task would be sustained were both found to be significantly better wearing an OBPLAD.Conclusion: The findings of the study imply that the Jaipur belt could potentially delay the onset of fatigue in the trunk muscles while performing repetitive lifting task and hence, is proved to be useful in the prevention of fatigue-related musculoskeletal disorders of the lower back.CTRI Registration date: 10/02/2020 Trial registration number: CTRI/2020/02/023219


2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Charles Tembo ◽  
Allan Maganga ◽  
Peterson Dewah

 This article presents various points of view regarding the treatment of sunken fontanelle by various communities as ignited by the controversial practice of kutara(a practice that involves the father of a child sliding his penis from the lower part of the left and right cheeks to the top of the head, as well as from the lower part of the face to the top of the head, and from the lower back part of the head to the top). The story of Alick Macheso’s use of his manhood to treat nhova (sunken fontanelle) opened a Pandora’s box. The story not only attracted the attention of critics from diverse cultural and ethical backgrounds, but revealed multi-ethnic positions. That is, reactions were steeped in a multiplicity of intellectual, religious and even cultural grounding. Reactions ranged from accusations of backwardness and absurdity, through to medical and Christian orientations toward the treatment of nhova. The overarching idea is that there is a general tendency to dismiss the age-old practice of kutara,coupled with an uncritical celebration of certain positions. The debate that ensued following publication of the story seemed to revolve around ethical considerations. The school of thought that dismisses kutara with disdain regards it as unethical and unimaginable in the present-day world—it is redolent with insinuations of absurdity on the part of those that live and celebrate it. We contend that the raging debate that followed the publication of the story can best be conceptualised within the context of African ethics. We note that kutara has relevance to the spirituality, ethical values, privacy, and protection of children’s rights, among other ethical issues. It is hoped that the article will stir further debate and encourage more research among information practitioners, scholars and researchers into the ethical issues surrounding the treatment of sunken fontanelle in various African communities. It argues for an Afrocentric conceptualisation of phenomena in order to contribute to debates on the renaissance of African cultures, and stresses that it is imperative to harness the life-furthering age-old traditions in African ontological existence.


Author(s):  
Brian D. Lowe

Psychophysical approaches to quantifying perceived effort have been used to evaluate the physical demand of many industrial work activities. An experiment was conducted to examine the relationship between ratings of whole-body perceived exertion and differentiated, regional ratings of exertion. The Borg, CR-10 scale was used by 16 subjects performing a simulated repetitive lifting task. Ratings of perceived exertion were obtained for the arms, legs, torso, and central (cardiorespiratory) effort sensations as well as a rating of overall, whole-body exertion. A multiple linear regression analysis was used to predict the whole-body rating of exertion from the differentiated ratings in lifting tasks using both a squat and stoop posture. In the stoop posture condition the coefficient of determination between whole-body perceived exertion and the model including arm, torso, and central ratings was R2=0.81. In the squat posture condition, the final regression model predicting whole-body exertion contained only the rating from the legs (R2 = 0.62). Differentiated ratings explained the majority of the variance in whole-body perceived exertion for squat and stoop lifting tasks.


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