scholarly journals Assessment of Muscular Activity and Postural Load During Coffee Harvesting Activities – A Case Study

2020 ◽  
Vol 24 (1) ◽  
Author(s):  
Sebastián Alberto Pelaez ◽  
Leonardo Augusto Quintana
Keyword(s):  
Maximum Voluntary Contraction ◽  
Muscular Activity ◽  
Voluntary Contraction ◽  
The Body ◽  
Repetitive Movement ◽  
Dynamic Activity ◽  
Activity Assessment ◽  
Lower Back ◽  
Postural Load

Objective: The goal of this case study was to analyze and evaluate the posture, force and repetitive movement risks associated with manual coffee harvesting activities. Materials and Methods: A self-discomfort report was administered to 28 participants, of whom 4 volunteered for an evaluation of postural load on muscular activity using electromyography and electrogoniometry. Eight upper limb muscles and the kinematics of the wrist and upper arm of the dominant arm were assessed. Results: The results of the self-discomfort report showed a greater demand, from the harvester’s perception, in areas such as the back, lower back, knees and feet during a period of one week of work. The outcomes of the muscular activity assessment showed that the extensor carpi ulnaris (ECR) was the muscle with the highest demand during the assessment. The dynamic activity of the muscle exceeded 20% of the maximum voluntary contraction (MVC), which classifies coffee harvesting as a threatening activity. The postural load on the body segments revealed that wrist deviation was critical due to an abnormal range of the wrists during the activity. Conclusions: It is necessary to improve the working conditions of the coffee harvesters.

scholarly journals Análisis biomecánico en la actividad de recolección café en Colombia

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
Sebastián Alberto Peláez-Gómez ◽  
Luis Eduardo Rodríguez-Cheu
Keyword(s):  
Muscular Activity ◽  
The Body ◽  
Body Segments ◽  
Lower Back ◽  
Muscular Load ◽  
Biomechanical Evaluation ◽  
Hands And Feet ◽  
Coffee Sector ◽  
Load Evaluation

During this case study, the risks of posture, strength and repetition associated with the activity of manual coffee harvesting were evaluated. The sample studied was 26 volunteers who participated in the completion of a Nordic questionnaire, 10 of these were evaluated using observational,and postural tools and 8 people participated in the biomechanical evaluation of postural and muscular load using electromyography and inertial. Seven muscles and two body segments of the upper limbs were evaluated. The goal was to assessthe working conditions of coffee manual harvesting considering ergonomics.The results of the discomfortsweremanifested in the Nordic questionnaire where it was evident that throughout a workday harvesting coffee, the discomfort focuses on the back, lower back, hands,and feet. In the muscle load evaluation was identified that the muscles with the highest activity were the Extensor, Flexor Carpi Ulnar and the trapezius.On average,their muscular activity was20% of their maximum volunteer contraction when performing the statistical analysis. -Tics showed a greater correlation in muscle activationbetween the Carpi Radial Extender and the trapezius. In the postural evaluation of the body segments from the coffee harvesters evaluated, it was identified that they only maintain between 10% and 20% in neutral ranges, so they are always in risky conditions. In conclusion, it is necessary to carry out interventions in the Colombian coffee sector not only because of these evaluated conditions but also for theconditions in theirwork environment.

scholarly journals Effect of kinesio taping in myoelectric activity in patients with shoulder impingement

2020 ◽  
pp. 1-7
Author(s):  
William Dhein ◽  
Marcelo La Torre ◽  
And Jefferson Fagundes Loss
Keyword(s):  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
The Body ◽  
Wilcoxon Test ◽  
Shoulder Abduction ◽  
Myoelectric Activity ◽  
Kinesio Taping ◽  
Upper Trapezius ◽  
Occupational Activities ◽  
Impact Syndrome

Introduction: The complex shoulder joint is equipped with the greater joint mobility of the body, however, is commonly injured in repetitive, sport or occupational activities. Shoulder Impact Syndrome (SIS) is one of the most common injuries affecting the shoulder, thus causing limitations in its functionality. Several strategies have been used by physiotherapy for prevention and rehabilitation of SIS, one of them is the Kinesio Taping (KT). However, even with its abundant use there is still no clear evidence of its benefits. Objective: The aim of the study was to examine the effect of KT on myoelectric activity and the level of pain in patients with SIS. Method: Seven women with SIS participated, which performed the flexion and shoulder abduction up to 90° with and without KT. During the gestures, the pain level and surface electromyography data of the upper trapezoid, middle deltoid and anterior serratus were acquired. The treatment of the electromyography data was performed in the BIOMEC-SAS software and presented as percentage values of the maximum voluntary contraction. To compare the myoelectric activity and pain levels, it was performed, respectively, one way ANOVA and the Wilcoxon test (α <0.05). Results: Pain reductions were observed and myoelectric activity of upper trapezius (46.0±34.4% MVIC to 35.6 ± 19.5% MVIC) and middle deltoid (39.0±11.5% MVIC to 35.2±12.5% MVIC) in motion abduction use of KT. No changes were observed in the signs during flexion movement. Conclusion: Finally, the KT generated a reduction in the level of pain and myoelectric activity of the middle deltoid and upper trapezius in the movement of abduction in patients with SIS.

scholarly journals Development and Experimental Verification of an Ergonomic Backpack

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Mohamed Z. Ramadan ◽  
Sultan N. Al-Tayyar
Keyword(s):  
Body Weight ◽  
Experimental Verification ◽  
Continuous Monitoring ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
The Body ◽  
Oblique Muscle ◽  
Independent Variables ◽  
Reducing Activity ◽  
Spinal Muscles

Carrying a heavy school backpack has extensively been reported as a prime cause of children’s body strain. It is suggested that the load should not exceed 10 percent of the child’s body weight; however, ensuring this requires continuous monitoring. The study explores how ergonomically designed school backpack based on the user anthropometric data (n=280) and ergonomic parameters help reduce force concentration on shoulders and back. It provides a validation process of the developed prototype by experimental verification. The developed design was assessed in a comparison experiment with a commercially available local school backpack. An experimental study was used which recruited thirty healthy college students (aged 19 to 23 years). Two independent variables evaluated were school backpack type (developed backpack versus commercial one) and load levels as a percentage of body weight. Three load levels were employed 10%, 15%, and 20%. These variables were measured on the responses: bag comfort scale and the percent of maximum voluntary contraction (%MVC) of six muscles (right and left of erector spine, right and left of external abdominal oblique muscle, and right and left of trapezius). The developed backpack provided astonishing performance at levels of 15% and 20% of body weight in terms of subjective measure and electromyography (EMG) responses. It also showed that increasing the carried weight more than 10% result in reducing activity on the erector spinal muscles, while it increases on abdominal oblique muscles. The developed backpack design confirmed the efficiency of its bases by distributing the carried weight among the trunk through side pockets, attached to the body through two upper and lower straps. It helped the body to distribute the carried weight and avoid concentrating pressure on specific areas.

scholarly journals Dynamics of forearm muscle activity in slanted computer mice use

Work ◽  
2020 ◽  
pp. 1-13
Author(s):  
Denis A. Coelho ◽  
Miguel L. Lourenço
Keyword(s):  
Maximum Voluntary Contraction ◽  
Muscular Activity ◽  
Surface Emg ◽  
Voluntary Contraction ◽  
Musculoskeletal Health ◽  
Hand Size ◽  
The Difference ◽  
Forearm Muscle ◽  
Muscular Activation ◽  
Activity Dynamics

BACKGROUND: Static muscular activity of muscles activated in the use of the conventional PC mouse is believed to represent a higher risk for the musculoskeletal health of the user than dynamic muscular activity. OBJECTIVE: This paper presents a compounded muscular activity dynamics indicator (akin to percent relative range), enabling comparison between computer handheld pointing devices. METHODS: This muscular dynamism approach considers baseline muscular activity (APL, ECR, ECU and ED) relative to the Maximum Voluntary Contraction as well as the dynamics of muscular activation. The latter is computed as the ratio of the difference between APDF90 and APDF10 divided by APDF50 (APDF-Amplitude Probability Distribution Function for the 90th, 50th and 10th percentiles). The paper demonstrates the approach with results of comparative evaluation of a horizontal, a slanted and a vertical PC mouse, through surface EMG monitoring of 20 participants performing standardized graphical task with the devices. RESULTS: Hand size impacts muscular activity dynamics in these four muscles, which supersedes differences in device geometry, across the range of devices tested. CONCLUSION: Smaller devices relative to hand size foster more dynamic muscular activity.

Whole-Body Reaching Movements Formulated by Minimum Muscle-Tension Change Criterion

2016 ◽  
Vol 28 (5) ◽  
pp. 950-969 ◽  
Author(s):  
Naoki Kudo ◽  
Kyuheong Choi ◽  
Takahiro Kagawa ◽  
Yoji Uno
Keyword(s):  
Muscle Tension ◽  
Maximum Voluntary Contraction ◽  
Weighting Factor ◽  
Voluntary Contraction ◽  
The Body ◽  
Joint Torque ◽  
Reaching Movements ◽  
Whole Body ◽  
Hand Position ◽  
Tension Change

It is well known that planar reaching movements of the human shoulder and elbow joints have invariant features: roughly straight hand paths and bell-shaped velocity profiles. The optimal control models with the criteria of smoothness or precision, which determine a unique movement pattern, predict such features of hand trajectories. In this letter on expanding the research on simple arm reaching movements, we examine whether the smoothness criteria can be applied to whole-body reaching movements with many degrees of freedom. Determining a suitable joint trajectory in the whole-body reaching movement corresponds to the optimization problem with constraints, since body balance must be maintained during a motion task. First, we measured human joint trajectories and ground reaction forces during whole-body reaching movements, and confirmed that subjects formed similar movements with common characteristics in the trajectories of the hand position and body center of mass. Second, we calculated the optimal trajectories according to the criteria of torque and muscle-tension smoothness. While the minimum torque change trajectories were not consistent with the experimental data, the minimum muscle-tension change model was able to predict the stereotyped features of the measured trajectories. To explore the dominant effects of the extension from the torque change to the muscle-tension change, we introduced a weighted torque change cost function. Considering the maximum voluntary contraction (MVC) force of the muscle as the weighting factor of each joint torque, we formulated the weighted torque change cost as a simplified version of the minimum muscle-tension change cost. The trajectories owing to the minimum weighted torque change criterion also showed qualitative agreement with the common features of the measured data. Proper estimation of the MVC forces in the body joints is essential to reproduce human whole-body movements according to the minimum muscle-tension change criterion.

scholarly journals Proposal of Non-Rotating Joint Drive Type Power Assist Suit for Lower Limbs Considering Squat Lifting

2018 ◽  
Vol 30 (5) ◽  
pp. 752-761 ◽  
Author(s):  
Hirokazu Arakawa ◽  
Shun Mohri ◽  
Yasuyuki Yamada ◽  
Kazuya Yokoyama ◽  
Isao Kikutani ◽  
...  
Keyword(s):  
Back Pain ◽  
Lower Back Pain ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Lower Limbs ◽  
Joint Torque ◽  
Health Concern ◽  
Lumbar Region ◽  
Lower Back ◽  
Squat Lifting

Lower back pain is a major health concern worldwide. One cause of lower back pain is the burden on the lumbar region caused by handling heavy objects. The Ministry of Health, Labour and Welfare in Japan has recommended “squat lifting” to reduce this burden. However, this technique, which supports a large force on the lower limbs, is not very popular. Therefore, we aim to develop a power assist suit for squat lifting and propose herein a gastrocnemius-reinforcing mechanism. We also discuss the joint torque estimation from a motion analysis of squat lifting to construct a prototype. Finally, we describe the performance of the prototype when mounted on a human body. We found that when using the prototype assist suit, the %MVC (maximum voluntary contraction) of the gastrocnemius while performing squat lifting reduced by 48% compared to the value obtained without using the suit.

scholarly journals FUNCTIONAL BANDAGE ON BIOMECHANICAL PARAMETERS IN THE KNEE

2020 ◽  
pp. 40074-40079
Author(s):  
Keyword(s):  
Muscle Activation ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Descriptive Case Study ◽  
Acute Response ◽  
Postural Changes ◽  
Neuromuscular Responses ◽  
Infrared Cameras ◽  
Gait Support

Background: Postural changes in the lower limb influencebiomechanically and functionally the other joint complexes, which may be related to myofascial dysfunctions. The functional elastic bandages seem to promote muscle activation that may go against the valgus pattern of the knee. Objective: To evaluate the acute response of the use of elastic bandages applied in the direction of the line of action of both fascial chains, valgus or varus, during a gait cycle. Methods: A descriptive case study was carried out with a young adult volunteer with genuine valgus and pronated feet. Electromyographic data were collected from the Middle Gluteal, Tensor Fascia Lata, Vasto Lateral and Vasto Medial muscles during gait at two speeds and two techniques for applying different functional bandages. The order of speeds and techniques for applying functional bandages was randomized by simple drawing. For the kinematic capture of gait, support and balance cycles, a Cinemetry system with 6 infrared cameras was used. The Electromyographic signal was processed to obtain the maximum voluntary contraction. Results: The results were divided into a sign of inhibited muscle activation or with greater activation during the execution of the movement. There was greater activation of the middle gluteal muscle during the support phase in gait with the use of varus banding and greater activation of the vastus during the same phase with the use of valgus bandage. Conclusion: In this case study, different strategies for applying functional bandages impacted different neuromuscular responses during gait.

scholarly journals Parylene-Based Flexible Microelectrode Arrays for the Electrical Recording of Muscles and the Effect of Electrode Size

2020 ◽  
Vol 10 (20) ◽  
pp. 7364
Author(s):  
Bong-Jun Choi ◽  
Ju-Hwan Kim ◽  
Woo-Jin Yang ◽  
Dong-Jun Han ◽  
Jaewon Park ◽  
...  
Keyword(s):  
Small Area ◽  
Microelectrode Array ◽  
Maximum Voluntary Contraction ◽  
Microelectrode Arrays ◽  
Specific Area ◽  
Skin Surface ◽  
Voluntary Contraction ◽  
The Body ◽  
Electrode Size ◽  
Semg Signals

Miniaturized flexible microelectrode arrays are desirable for small-area surface electromyography (sEMG) to detect the electrical activity generated by muscles in a specific area of the body. Here, we present a flexible 8-channel microelectrode array with electrodes of diameter 150–300 μm for small-area sEMG recordings. The microelectrode arrays based on a flexible Parylene C substrate recorded the sEMG signals from a curved skin surface with a maximum signal-to-noise ratio (SNR) of 21.4 dB. The sEMG signals recorded from a small area of 17671–59325 μm2 showed a clear distinction between the signal and noise. Further, the sEMG data were analyzed in the frequency domain by converting the signals via fast Fourier transform (FFT), and it was verified that the proposed microelectrode could reliably record multichannel sEMGs over a small area. Moreover, a maximum voluntary contraction (MVC) experiment was performed to confirm the recording capability of the microelectrode array, which showed consistency with the previous reports. Finally, we demonstrated the effects of the electrode size by comparing the results for two different electrode sizes. When the electrode size was increased 3.37 times, the root-mean-square value of the amplitude (Vrms) increased 2.64 times, consequently increasing the SNR from 16.9 to 21.4 dB. This study demonstrates the expanded utility of Parylene-based flexible microelectrode arrays.

scholarly journals The Effect of Vibration on Muscle Activity and Grip Strength Using an Electric Drill

2013 ◽  
Vol 10 ◽  
pp. 318-323 ◽  
Author(s):  
Mirta Widia ◽  
Siti Zawiah Md Dawal
Keyword(s):  
Grip Strength ◽  
Muscle Activity ◽  
Maximum Voluntary Contraction ◽  
Muscular Activity ◽  
Voluntary Contraction ◽  
Wood Material ◽  
Percentage Decrease ◽  
Hand Dynamometer ◽  
Electric Drill ◽  
Extensor Carpi Radialis

The paper focused on the effects of vibration exposure on muscle activity and grip strength. The study was conducted on eighteen subjects, required to drill wood material using electric drill for 5 and 15 minutes. Electromyography (EMG), Vernier Labpro with 3 axis accelerometer and hand dynamometer were used in the experiment. The results showed that right extensor carpi radialis muscle had the highest percentage of Maximum Voluntary Contraction (MVC) with values of 21.8%MVC-23.5%MVC. The mean vibration level was 10.45 m/s2 (5 minutes) and 10.69 m/s2 (15 minutes). Drilling wood material for 15 minutes resulted in higher percentage MVC (7.79%), vibration levels (2.29%), and percentage decrease ratio (11.17%) than using 5 minutes for the extensor carpi radialis muscle. The findings of the study indicated that as the level of vibration and exposure duration increase the muscular activity and the percentage decrease ratio of grip strength would also increase.

HIPEREMESIS GRAVIDARUM PADA IBU HAMIL DI KLINIK BIDAN SUPRIYATI SRIBIT BERBAH SLEMAN

2019 ◽  
Vol 14 (1) ◽  
pp. 51
Author(s):  
Pramukti Dian Setianingrum ◽  
Farah Irmania Tsani
Keyword(s):  
Blood Pressure ◽  
Pregnant Women ◽  
Hyperemesis Gravidarum ◽  
Unwanted Pregnancy ◽  
The Body ◽  
Nausea And Vomiting ◽  
Daily Activities ◽  
World Health ◽  
The World

Backgroud: The World Health Organization (WHO) explained that the number of Hyperemesis Gravidarum cases reached 12.5% of the total number of pregnancies in the world and the results of the Demographic Survey conducted in 2007, stated that 26% of women with live births experienced complications. The results of the observations conducted at the Midwife Supriyati Clinic found that pregnant women with hyperemesis gravidarum, with a comparison of 10 pregnant women who examined their contents there were about 4 pregnant women who complained of excessive nausea and vomiting. Objective: to determine the hyperemesis Gravidarum of pregnant mother in clinic. Methods: This study used Qualitative research methods by using a case study approach (Case Study.) Result: The description of excessive nausea of vomiting in women with Hipermemsis Gravidarum is continuous nausea and vomiting more than 10 times in one day, no appetite or vomiting when fed, the body feels weak, blood pressure decreases until the body weight decreases and interferes with daily activities days The factors that influence the occurrence of Hyperemesis Gravidarum are Hormonal, Diet, Unwanted Pregnancy, and psychology, primigravida does not affect the occurrence of Hyperemesis Gravidarum. Conclusion: Mothers who experience Hyperemesis Gravidarum feel nausea vomiting continuously more than 10 times in one day, no appetite or vomiting when fed, the body feels weak, blood pressure decreases until the weight decreases and interferes with daily activities, it is because there are several factors, namely, hormonal actors, diet, unwanted pregnancy, and psychology.

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