Showing 12 results for Hand
M Motamedzadeh, M Shafiei Motlagh, E Darvishi,
Volume 3, Issue 1 (5-2013)
Abstract
Introduction: Manual material handling activities in long and short periods may lead to complications such as laceration, fracture, cardiovascular stress, muscle fatigue, and musculoskeletal disorders especially in the vertebrae column. The purpose of this study was to assess manual handling of oxygen cylinders by casting workers and to implement ergonomic intervention to reduce the risk of musculoskeletal disorders.
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Material and Method: This is an interventional study conducted among 18 male workers of a steel casting unit. Assessment of manual handling of oxygen cylinders, was done using in order Snook tables. The manual handling of oxygen cylinders was changed to mechanical handling and making a box with the capacity of 16 oxygen cylinders which can be moved by crane.
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Result: According to the results, lifting and lowering cylinders was not suitable for most of the workers. Moreover, caring, pulling and pushing was suitable for less than 10 percent of the workers. Condition of lifting cylinders by fire workers was suitable only 25 percent of them. According to the snook tables material handling activities must be suitable for at least 75 percent of workers.
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Conclusion: With the implementation of ergonomic intervention is casting unit, the risk of exposure to musculoskeletal disorders caused by manual handling of oxygen cylinders was eliminated and safety of employees against the risk of explosion of the cylinders in comparison with before the intervention was improved.
P. Nassiri, I. Ali Mohammadi, M. H. Beheshti, K. Azam,
Volume 3, Issue 2 (8-2013)
Abstract
Introduction: The power tiller is a multipurpose hand tractor designed primarily for rotary tilling and other farm operations. Vibration, transmitted from the handles of the tiller to the operators’ body, causes many injuries such as, pain, musculoskeletal disorders and white finger syndrome. The aim of this study was to evaluate the hand-arm vibration exposure in the operators of tiller model HT900, as the most frequently used model of tillers.
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Material and Method: In this study, 40 operators tiller of model HT900 in the city of Kashmar, Khorasan Razavi were examined. Hand-arm vibration measurement was done according to ISO 5349-1 and ISO 5349-2 in three different modes including, static and neutral (mode), transition to the ground mode and plowing the land mode in different gears. In order to measure the vibrations, human response vibration meter of B and K model 2512 was utilized.
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Result: Results of the present study indicated that in all measured situations, exposure to hand arm vibration was higher than the standard limit suggested by Iranian occupational health committee and there was risk of vibration-induced disorders. The maximum exposure to vibration is in plowing ground. Exposure to hand arm vibration in three modes of plowing, transmission and natural, were respectively 16.95, 14.16 and 8.65 meters per second squared. Additionally, in all situations, vibration exposure was highest in the X-axis in comparison with Z- and Y-axes.
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Conclusion: This study emphasizes on the need to provide intervention and controlling and managing strategies in order to eliminate or reduce vibration transmitted from tiller to operators hand and arm and also prevent to serious problems including neurovascular disorders, discomfort and white finger syndrome. Meanwhile, more studies are necessary to identify the sources of vibration on different models of tiller.
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Volume 3, Issue 2 (8-2013)
Abstract
Introduction: Musculoskeletal disorders are the most prevalent problem in the workplace. Unsafe manual material handling is amongst important causes of such disorders. Unsafe manual material handling can result in different musculoskeletal disorders such as acute physical injuries and increase of strain in back, shoulders and arms. United state society of orthopedic surgeons ranked back pain as the most costly disorder, which workplaces are considered to be responsible for most of them. Few studies compare related national and non-national standards in Iran. Therefore, the aim of the present study was to compare Iranian manual material handling regulation, NIOSH equation and MAC method in one of metal casting industries in Tehran, 2001.
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Material and Method: In this cross-sectional study, participants were randomly selected among men workers, working in industry. Data collection was done using MAC data sheet, NIOSH equation and Iranian MMH regulation. Data were Analyzed using stata software and P-value of 0.05 or less was considered significant.
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Result: Results showed an acceptable agreement between Iranian regulation and MAC method as well as Iranian regulation and NIOSH equation. However, no acceptable agreement was observed between MAC method and NIOSH equation.
T. Allahyari, H. R. Khalkhali, F. Khanehshenas,
Volume 3, Issue 4 (2-2014)
Abstract
Introduction: Manual dexterity impairment due to wearing latex and nitrile gloves among health care employees and laboratory personnel can be a remarkable problem because of its adverse outcomes. The present study was conducted to “compare the effect of using latex and nitrile laboratory gloves on hand dexterity”.
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Material and Method: In a semi experimental study design, 30 university were students randomly selected from Urmia University of medical sciences. Subjects assigned in three experimental conditions, such as the control condition (without gloves), with latex glove and with nitrile gloves. Then, dexterity level of fine finger and gross of the subjects were calculated using the Purdue pegboard test. Repeated measures one-way ANOVA test and T-test and Pearson’s correlation coefficient were used for statistical analysis.
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Results: The result showed that the differences between three groups of laboratory conditions from the level of gross and fine finger dexterity were statistically significant (p‹0.05). As the latex gloves showed significant and positive effect on gross and fine finger dexterity comparable with nitrile gloves and control group but there was no significant difference between the gross and fine finger dexterity of nitrile gloves when comparing with the control group. In other words, the nitrile gloves had not negative effect on gross and fine finger dexterity.
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Conclusion: Considering that there was no significant difference in the score of both fine finger and gross hand dexterity while using nitrile gloves as compared to the control condition (without gloves), means that use of nitrile gloves has no adverse effect on hand dexterity therefore, using nitrile gloves is recommended as a alternative for the latex gloves, considering the additional advantage of no allergic reaction in this gloves.
E. Darvishi, A. Shafikhani, A. A Shafikhani,
Volume 5, Issue 1 (4-2015)
Abstract
Introduction: Manual material handling (MMH) is the most common cause of work-related Musculoskeletal Disorders (MSDs). Prevention of MSDs is highly critical. The aim of this study was to assess risk of carpets manual handling by retail workers, and to implement ergonomic interventions in order to reduce risk of MSDs.
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Material and Method: This interventional study was conducted among 36 workers in 19 retailer sites of a textile corporation. Ergonomics assessment of the retailers was done using the comprehensive risk assessment model of the British Carpet Foundation. Moreover, the Nordic Musculoskeletal Questionnaire was used to determine the prevalence of workers’ MSDs. Reassessment was conducted after implementation of the ergonomics interventions.
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Result: The mean age and work tenure of participants were 36.28 and 16.2 years, respectively. The results of Nordic Questionnaire before intervention showed that overall 37.8% of the workers had experienced pain at least once during the past year, with the highest frequency belonged to the lower back (75%), shoulder (61%), and neck and upper back (55%), respectively. After implementing the interventions, the prevalence of MSDs reduced to 23.5%. The results of risk assessment before and after the interventions showed that of the 19 retailer sites, six sites were improved from poor to average state, and one site showed improvement from average to good condition.
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Conclusion: By implementing ergonomics interventions in carpet delivery sites, the risk factors of MSDs, induced by manual carpet handling, were reduced and safety and ergonomic conditions of the retailers were improved, compared to the previous conditions.
Fateme Dehghani, Seyed Abolfazl Zakerian, Asma Zare, Fariborz Omidi, Zahra Moradpour, Abouzar Eynipour, Masoud Ghanbari Kakavandi,
Volume 6, Issue 4 (12-2016)
Abstract
Introduction: A high percentage of musculoskeletal disorders in workplaces occur due to awkward posture and non-ergonomic design of the work stations for lifting and carrying of materials. To avoid these injuries, jobs should be designed in a way that ergonomics risk factors are controlled properly. The aim of this study was to utilize ergonomics interventions to minimize ergonomics risk factors in bag packing unit in a mineral processing plant.
Material and Method: This cross sectional study was carried out among 20 workers of bag packing unit. Camera recording of working postures, evaluation of medical records, interview, and REBA technique were used to identify the ergonomic risk factors. Interventions included changing the conveyor belt height and the use of spring pallets (spring table). Data were analyzed using Paired T-Test by SPSS software version 18.
Result: Before implementing ergonomics intervention, a total of 75% of evaluated postures by REBA technique obtained score of 8-10 (very high risk level) and 25% had score of 11-15 (very high risk level) that correspond to the action level 3 and 4, respectively. Following the implementation of ergonomics interventions, a total of 90% of the analyzed postures showed action level 2 (moderate risk level) and the remainder 10 percent of evaluated postures showed high risk level. Comparison of REBA technique scores before and after implementing interventions showed a significant difference (P-value < 0.05).
Conclusion: Based on the findings of this study, the implementation of ergonomics interventions has remarkably decreased the required action level and it may be able to improve work-related postures.
Faranak Masakini, Fatemeh Noorbakhsh, Sahar Honarmand Jahromi,
Volume 7, Issue 4 (12-2017)
Abstract
Introduction: Hospital acquired infections recognize as an important risk factor in health care. In this regard health care and hand hygiene is the first step in controlling the infections. This study, carried out with the aim of comparing the effect of hand washings in the usual way with disinfectants without water in microbial contamination of the hospitals hand nurses.
Material and Method: Accordingly, samples were taken from hand of 30 nurses in the wards of surgery, pediatrics, emergency, CCU, ICU and cardiology in 4 steps before and after washing with soap and washing with liquid hand rub. Samples were cultured in EMB and Blood Agar medium, then identified by gram staining, catagase and coagugas tests and growth on manitol salt agar.
Result: The findings showed that 30 samples were not grown on EMB medium، but 30 samples of Blood agar, before and after washing with soap and liquid hand rub, were grown and applying hand rub alcohol liquid is most effective than washing with soap. Identification of bacteria in manitol salt agar medium and coagulas test revealed %80 were coagulas negative staphylococcus and %20 coagulas positive staphylococcus.
Conclusion: In this study washing with soap dose not effect on hand hygiene of nurses but disinfectant with liquid alcohol shows significant correlation in reducing microbial load on personnels’ hand that is revealed alcohol was more effective in reducing pollution.
Samira Barakat, Behnam Moradi,
Volume 11, Issue 3 (9-2021)
Abstract
Introduction: Long-term exposure to hand-arm vibration causes musculoskeletal disorders mainly in hand and shoulder. The purpose of this study was to determine the effect of sport and using anti-vibration gloves on the grip strength of workers exposed to the hand-arm vibration.
Material and Methods: In this descriptive-interventionist study, 41workers working in one of the Isfahan metal industries were studied. Data were collected by the demographic questionnaire, hand-arm vibration acceleration measurement was performed based on the ISO 5349 standard and grip strength was measured using the dynamometer device model Jamar. The investigations were performed on 3 groups including sporting moves, using of anti-vibration gloves and combination of sporting move and using of gloves. Twenty workers were selected as control group without exposure to any hand-arm vibration. Data were analyzed by the SPSS-21 software.
Results: Workers’ grip strength difference was significant before and after vibration (PValue<0.001) and grip strength had significant and inverse relation with vibration (PValue<0.001, R= -0.411). Grip strength was higher in the group that used anti-vibration gloves accompanied with the sporting moves compared to before the intervention and significant relation was observed (PValue<0.001).
Conclusion: Vibration affects decreasing in grip strength and grip strength itself can be used as a screening measure for those workers exposed to the risk and diseases related to the vibration. Regular sporting moves and using anti-vibration gloves are effective on improvement of workers’ grip strength and preventing vibration-induced complications.
Masoud Feyzi, Ali Jafari, Hojat Ahmadi,
Volume 12, Issue 2 (6-2022)
Abstract
Introduction: Due to the non-developed mechanization situation, chainsaw is a widely used tool in Iranian forests. This tool can trigger unwelcome disorders (e.g., white finger syndrome) due to the transmitted vibrations from its handle to the body members. Characterizing these vibrations can result in minimizing the intensity of these disorders. This study aims to investigate the effect of different hardwood species (Beech, Hornbeam, and Alder) on the vibrations transmitted to the wrist and arm.
Material and Methods: Experiments are conducted during four operations including Beech-, Hornbeam-, and Alder-cross-cutting and without cutting as the control sample. Vibration accelerations in three directions of a local Cartesian coordinate system are measured at three points including chainsaw handle, operator's arm and wrist. Using the time and frequency spectra of vibration accelerations, root mean square (RMS), total vibration acceleration, total vibration transmissibility, and frequency-weighted vibration acceleration are calculated based on ISO 5349 (2001) and ISO 10819 (2013) standards. The calculated parameters were statistically analyzed in SAS.
Results: The results showed that variations in wood species could significantly affect the RMS at all three points. The RMS magnitude decreases from handle towards the arm. Interestingly, a significant variation in vibration transmissibility is observed in different frequencies. This study confirms that body organs can damp the high-frequency vibrations better than the low frequency ones.
Conclusion: Although the RMS for cutting operations is less than the control sample, frequency-weighted vibration acceleration and consequently the risk of white finger syndrome is higher in cutting regimes. Furthermore, some vibration accelerations (below 40 Hz for wrist and below 25 Hz for arm) are amplified during transmission despite significant damping in total vibrations.
Kaykāvus Azrah, Ali Khavanin, Majid Shahi, , Mahbubeh Parsaeian, Mohammad Reza Monazzam,
Volume 12, Issue 4 (12-2022)
Abstract
Introduction: This study aims to determine the amount of hand-arm vibration transmitted from heavy electric destruction tools and the effect of using chisel with different lengths and shapes when demolishing concrete surfaces.
Material and Methods: To evaluate the magnitude of hand-arm vibration on the left and right handles of two powerful electric demolition hammers commonly applied in Iranian construction work and urban services, 323 measurements were made (RONIX and NEC). The demolition procedure was carried out by two experienced users on 49 concrete slabs of the same grade (20 C) with thicknesses of 10 and 15 cm while utilizing standard tools, such as hammers with two different chisel head shapes (flat and point) and lengths (40 and 60 cm). Utilizing two SVANTEK vibration meters concurrently on each hammer handle, measurement and evaluation were according to the ISO 5349:1, 2 procedures.
Results: The mean effective (frequency weighted root mean square) acceleration (awrms) for the Vector Sum Values (VSV) in the hammer handles were 15.71 m/s2. The primary vibrational axis transmitted to the handle of tool was the vertical axis, at 13.60 m/s2. When employing flat and point chisel, the mean awrms were 16.59 m/s2 and 14.82 m/s2, respectively. The difference between the results of 60 and 40 chisel was a little more than 2m/s2. The dominant and harmonic frequencies of the tools were generally in the range of 25 Hz to 80 Hz and 200 Hz to 400 Hz
Conclusion: The mean results generally indicated that point chisel with shorter lengths (40 cm) accelerates at a lower rate than flat chisel with longer lengths (60 cm). In the frequency range below 40 Hz, the RONIX hammer produced a larger acceleration than the NEC hammer indicating that the NEC hammer had a higher safety competitive advantage compared to the another hammer.
Hassan Mehridiz, Mohamad Sadegh Ghasemi Ghasemi, Hassan Saeedi, Mahsa Varmazyar, Ehsan Garosi,
Volume 14, Issue 2 (6-2024)
Abstract
Introduction: Lifting loads in awkward postures is a main cause of low back musculoskeletal disorders. In this context, researchers have used various indicators to determine the relationship between biomechanical variables and the risk of these disorders. This study aimed to investigate the correlation between plantar pressure distribution and the values of UTAH back-compressive forces (BCF) and lifting index (LI) during symmetrical load-lifting tasks.
Material and Methods: Thirteen healthy men, aged 25 to 35, took part in this study. The participants were instructed to symmetrically lift loads weighing 7.5 kg and 15 kg in 15 different postures, considering three horizontal distances (A, B, C) and five different heights (1-5). Pressure on the foot soles was recorded using 16 force-sensitive resistors (FSR) corresponding to eight anatomical areas on each foot. The BCF and LI were also calculated using the UTAH method and the NIOSH equation, respectively. Statistical analysis was performed using SPSS (version 21) software.
Results: Based on the results, when the load was closest to the body (A1-A5), the highest pressure was recorded in the heel and the 4th and 5th metatarsal of both feet. In lifting a load of 15 kg in the A2, B1, B2, C1, C2 postures and lifting a load of 7.5 kg in the C2 posture, the average BCF exceeded 700 pounds. The LI was greater than 1 for specific postures (B1, B2, B4, B5, C1-C5) at 15 kg and (C1, C2, C4, C5) at 7.5 kg load-lifting. During the 7.5 kg and 15 kg load-lifting, there was a significant correlation between the plantar pressure and the values of LI and UTAH (p-values < 0.05) in most postures.
Conclusion: The results showed a significant correlation between plantar pressure distribution and load-lifting postures. The study findings, which identify risk levels associated with lifting postures, lay the groundwork for future research aimed at categorizing safe and unsafe plantar pressure patterns.
Mohammad Sadegh Sohrabi, Atousa Rezayi, Tayeb Mohammadi, Mehrane Shabani,
Volume 14, Issue 3 (10-2024)
Abstract
Introduction: In all societies, tools and equipment are generally designed for right-handed people, who make up approximately 90% of the population, but left-handed and ambidextrous people (those who use both hands in manual activities) also live among us. Even in delicate and sensitive jobs. This research investigated the relationship between the spectral effect of the dominant hand and grip strength and hand dexterity.
Material and Methods: A cross-sectional study was designed to measure the power and precision grip of 182 adult participants (56% female and 44% male). The dominant hand of the participants was determined using the Edinburgh Dominant Hand Questionnaire. Power grip strength was measured using the Constant 14192-709E. Pinch grip test was performed using Saehan Hydraulic Pinch Gauge SH5005 for both hands separately. Dexterity of both hands was also measured using the Pegboard 32020A tool.
Results: Power and precision grips were more common in men than in women (P<0.001). Power grip differed between right- and left-handed women (P=0.019), with right-handed women having greater grip strength. The Precision grip of left-handed men was significantly (P<0.001) greater than that of right-handed men. Hand dexterity of left-handed men was significantly (P<0.001) higher than that of right-handed men. Two-handed agility (P<0.001) and assembly dexterity (P<0.001) are significantly higher in ambidextrous people than in right- and left-handed people.
Conclusion: The power, precision grip and dexterity are different between women and men. The grip strength of men is stronger than that of women. Ambidextrous people have more dexterity and assembly agility, so in jobs that require the use of two hands, they perform better and will be recommended for employment in this category of jobs.
