Electromyographic and subjective evaluation of hand tools: The example of masons' trowels

Association between objective and subjective measurements of comfort and discomfort in hand tools

“…All the above mentioned objective measures have proven to discriminate between hand tools. For example, differences in EMG were found between different types of masons' trowels, file handles, shovel handles and plate shears (Strasser et al, 1996;Kluth et al, 2004;Chang et al, 1999;Kilbom et al, 1993). A new designed scraper influenced hand-wrist postures (Eikhout et al, 2001) and grip force was found to discriminate between different types of plate-shears, meat cutting knives and shovel handles McGorry et al, 2003;Chang et al, 1999).…”

“…Methods to assess discomfort are 1) assessing the intensity of discomfort using a map of the palmar side of the hand (Groenesteijn et al, 2004;Kilbom et al, 1993;Kuijt-Evers et al, 2005), 2) rating handle discomfort (Kong and Freivalds, 2003;Chang et al, 1999) and 3) rating discomfort of whole body and hand . In other studies, properties of hand tools are evaluated like general handiness, and suitability for longer work (Kluth et al, 2004;Freund et al, 2000;Strasser, 1996;Chang et al, 1999;Groenesteijn et al, 2004). Comfort experience is considered in only a few hand tool evaluation studies (Kuijt-Evers et al, 2005;Freund et al, 2000).…”

“…In order to recognize ergonomically well-designed and comfortable hand tools, many hand tool evaluation studies have been conducted. Most studies combined objective measurements (to measure physical load) with subjective experiences of the subjects (to measure comfort or discomfort; e.g., Kluth et al, 2004;Strasser et al, 1996;Groenesteijn et al, 2004;Chang et al, 1999;Li, 2003;Kong andFreivalds, 2003, Freund et al, 2000).…”

“…In some cases, factors which have nothing to do with comfort or discomfort may influence the results. Therefore, objective measurements are used in addition to subjective measurements (e.g., electromyography (EMG) (e.g., Strasser et al, 1996;Fellows and Freivalds, 1991;Freund et al, 2000;Habes and Grant, 1997;Niemelä et al, 2000;Chang et al, 1999;Kadefors et al, 1993), hand-wrist postures (Eikhout et al, 2001;Kadefors et al, 1993), and grip force distribution and grip force (Fellows and Freivalds, 1991;Chang et al, 1999;McGorry, 2003). All the above mentioned objective measures have proven to discriminate between hand tools.…”

The effects of tool handle shape on hand performance, usability and discomfort using masons' trowels

“…It has been suggested that for reliable assessment of the ergonomic quality of a tool it is necessary to take into account both objective and subjective measurements (Strasser et al, 1996;KuijtEvers et al, 2007). Moreover, the combination of both objective and subjective evaluations enables the identification of new design factors in terms of the tool geometry parameters (P€ aivinen and Heinimaa, 2009).…”