Ergonomic evaluation of the effects of handle types on garden tools

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

“…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).…”

“…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 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.…”

“…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).…”

Identification and Analysis of Comfort Predictors in the Use of a Hand Tool

“…Different object measurements were performed to evaluate hand tools e.g., muscle activity [7][8][9], distribution of grip force [8]; [10] and hand-wrist postures induced [9]; [11] but still their relationships with user's comfort experience are unknown. The current study aims to identify the descriptors that predict comfort in using hammer and if possible classify the descriptors into meaningful groups or factors and identify the comfort predicting factors.…”