Relationship between the physical parameters of socket wrench hand tool with the electrical activity level of forearm muscles among maintenance unit workers of a university

Pouyakian, Mostafa; Ranjbarian, mohammad; khademi_kalantari, khosro; khodakarim, soheila; Ahmadlu, Mahnaz

Volume 17, Issue 1 (2020) ioh 2020, 17(1): 294-304 | Back to browse issues page

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Pouyakian M, Ranjbarian M, khademi_kalantari K, khodakarim S, Ahmadlu M. Relationship between the physical parameters of socket wrench hand tool with the electrical activity level of forearm muscles among maintenance unit workers of a university. , ioh. 2020; 17 (1) :294-304
URL: http://ioh.iums.ac.ir/article-1-2619-en.html

Relationship between the physical parameters of socket wrench hand tool with the electrical activity level of forearm muscles among maintenance unit workers of a university

Mostafa Pouyakian

, Mohammad Ranjbarian

, Khosro Khademi_kalantari

, Soheila Khodakarim

, Mahnaz Ahmadlu ^*

Shahid Beheshti University of Medical Sciences , m.ahmadlu89@gmail.com

Abstract: (4125 Views)

Background and aims: International Labor Organization (ILO) 2015 report shows that about 40% of the all total compensation for work-related diseases and accidents in the world is due to musculoskeletal disorders. According to UK Health and Safety Executive (2019) 41% of all registered Work related Musculoskeletal Disorders (WMSDs) are due to upper limbs. Barr et al. (2004) reported that most absence from work in the United States was due to musculoskeletal injuries to the hand and wrist. Hand, arm, and forearm are most important limbs of human body to work. Hand tools, especially non-powered hand tools, are responsible for a significant portion of damages. Many different types of hand tools are used in industrial, services, and domestic activities including wrenches, pliers, screwdrivers, clamps, snips, saws, etc. The use of hand tools is accompanied by repetitive movements and previous studies have shown that inappropriate design of hand tool can damage human joints, tendons and muscles. Repetitive movements are one of main causes of musculoskeletal injuries. In order to achieve high levels of comfort, safety, and efficiency of hand tools, physical abilities and limitations of users must be taken into account in design phase. Also, women and left-handed people must be considered in design of hand tools due to their different body dimensions and abilities. These factors are directly influences the trading of hand tools. Handle design is an important factor in the safe, convenient and ease of use of non-powered hand tools. Socket wrench is a single-wrench that is widely used to open and close the bolts and nuts that require high force and high speed operation. Due to wide usage of socket wrench this study aimed to investigate the relationship between physical parameters of length and diameter of handle, and weight of different models of socket wrench with electrical activity of two selected forearm muscles. We examined the correlation between three physical parameters of six trade model of socket wrenches.
Methods: This descriptive-analytical study performed among 58 male workers of the installation and maintenance unit staff of a university. Their ages ranged from 25 to 45 years. All participants were right-handed, healthy, and without history of upper limb injury or musculoskeletal disorders. They had at least one year of job experience in maintenance unit of university, and their body mass index was between 20-30. Six different types of socket wrench were selected and named with alphabetic codes A, B, C, D, E, F. Selected wrenches were differed in length and diameter of handle, and weight.

Keywords: Hand tool, Surface Electromyography, Ergonomics, Socket Wrench, Flexor Digitrum Superficialis, Extensor Carpi Radialis Brevis

Full-Text [PDF 472 kb] (2647 Downloads)

Type of Study: Applicable | Subject: Ergonomics
Received: 2018/11/20 | Accepted: 2019/11/27 | Published: 2020/07/6