Investigation of Grip Force, Normal Force, Contact Area, Hand Size, and Handle Size for Cylindrical Handles

Seo, Na Jin; Armstrong, Thomas J.

doi:10.1518/001872008x354192

Cited by 127 publications

(98 citation statements)

References 15 publications

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“…Relative to what is known about how stone tool related behaviours may have influenced the evolution of human hand anatomy, however, a great deal less has been empirically demonstrated in respect to how biometric variation may have impacted on technological choices and cultural variability in the Lower Palaeolithic. The notion that individual biometric differences significantly influence hand-held tool use or gripping tasks is, however, both long lived and widely supported within engineering and ergonomic literature (e.g., Tichauer and Gage, 1977;Hall, 1997;Ruiz-Ruiz et al, 2002;Edgren et al, 2004;Nicolay and Walker, 2005;Hwang et al, 2011), with it having been demonstrated on a number of occasions that optimal tool forms are directly related to the biometric traits of tool users (e.g., Eksioglu, 2004;Seo and Armstrong, 2008). Such considerations indicate that those tool forms that are of greatest functional value, and thus the tool forms most likely to be replicated, are determined by the biometric conditions observed in a tool user's upper limb.…”

Section: Introductionmentioning

confidence: 99%

Investigating interrelationships between Lower Palaeolithic stone tool effectiveness and tool user biometric variation: implications for technological and evolutionary changes

Key

Lycett

2016

Archaeol Anthropol Sci

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with cutting efficiency using both flakes and handaxes over extended periods of use and in multiple types of cutting task. Results indicate that (1) both handaxe and flake cutting efficiency is significantly related with biometric variation of individual tool-users, (2) relationships between biometric parameters and efficiency are consistent across extended durations but vary dependent upon task-type conditions, (3) manipulative strength is the most significant biometric trait in terms of predicting flake efficiency, while (4) hand size is the strongest predictor of handaxe cutting efficiency. These results demonstrate the long-term impact that stone tool use likely had on the evolution of hominin biometric variation during the Lower Palaeolithic, while also highlighting the variable influence of different tool use contexts.Most notably, results indicate that the onset of the Acheulean may have been dependent, a priori, upon hand dimensions that are close to the modern human range, and that prior to the appearance of this anatomy, handaxe use would have been an impractical (i.e. inefficient) tool use behaviour compared to the use of flakes.

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Section: Introductionmentioning

confidence: 99%

Investigating interrelationships between Lower Palaeolithic stone tool effectiveness and tool user biometric variation: implications for technological and evolutionary changes

Key

Lycett

2016

Archaeol Anthropol Sci

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“…The handle grip is improved by the optimum handle diameter in a way where it is easier to be secured in the hand and increases voluntary force applications. It is supported by other studies, where an optimal handle diameter increases the grip force and total normal force (Edgren et al, 2004;Kong and Lowe, 2005b;Mastalerz et al, 2009;Seo and Armstrong, 2008). At the same time, the secureness of the handle in the hand can be explained as the optimal handle diameter allowed the thumb and fingertips to work together against the palm, resulting in a greater reaction force (Seo and Armstrong, 2008).…”

Section: Effect Of Ergonomics Features On Handle Gripmentioning

confidence: 56%

“…At the same time, the secureness of the handle in the hand can be explained as the optimal handle diameter allowed the thumb and fingertips to work together against the palm, resulting in a greater reaction force (Seo and Armstrong, 2008). In addition, the grip force decreases along with the increase of the handle diameter beyond the optimal diameter (Edgren et al, 2004;Kong and Lowe, 2005b;Mastalerz et al, 2009;Seo and Armstrong, 2008).…”

Section: Effect Of Ergonomics Features On Handle Gripmentioning

confidence: 99%

“…A forceful exertion can cause localised fatigue (Rohmert, 1973;Seo et al, 2007) and damage to the human body structure (Armstrong et al, 1993), leading to the development of Cumulative Trauma Disorders (CTDs) (Falck and Aarnio, 1983). Previous studies suggested that the use of inward torque direction increases the total normal force and torque capacity and reduces the grip force (Seo and Armstrong, 2008;2011;Seo et al, 2007;2008a;2008b). This observation can be seen in the use of a normal manual screwdriver.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Usability Validation of an Ergonomic Inward Directional Screwdriver for Enhanced Musculoskeletal Comfort

Ng¹,

Choong²,

Jee³

2016

American Journal of Applied Sciences

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Previous studies suggested that the use of inward torque direction in hand-related manual activities not only increases the total normal force and torque capacity but also reduces grip force. This means lesser effort is required to perform the task, which prevents overexertion and hand injuries. Manual screwdrivers are the most common hand tools used in the industry and daily life. However, due to the difficulty users face when unfastening screws, it can also be a hand tool that potentially leads to the development of cumulative trauma disorders. In this study, 50 subjects participated in a psychophysical testing of an ergonomic inward directional screwdriver and a normal manual screwdriver. The comparative study involved the perceptions of grip, comfort and ease-of-twist for both normal and ergonomic manual screwdrivers. The data was analysed using the analysis of variance via Minitab 16. The results showed that grip, comfort and ease-of-twist are significantly affected by torque direction and ergonomics features. Further observations on participant justifications also suggested that participants rated the inward screwdriver as a better tool to be used compared to the normal screwdriver.

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“…Extensive studies have been carried out on grip force and the parameters that affect grip force, such as torque direction, object size and technique (Enders and Seo, 2011;Seo and Armstrong, 2008;Seo et al, 2008a;2008b). However, there appear to be no studies that investigate the effects of tactile sensation on pinch force.…”

Section: Introductionmentioning

confidence: 99%

Influences of Tactile Sensation on Pinch Force under Loaded and Unloaded Conditions

Ng¹,

Jee²,

Saptari³

et al. 2015

American Journal of Applied Sciences

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Although researchers have studied various parameters that affect grip force, few studies investigate the effects of tactile sensation on pinch force. This study aims to determine the influences of tactile sensation on pinch force with a special emphasis on screw knobs under loaded and unloaded conditions. The participants included 32 manual workers who were required to pinch and turn the knobs to generate pinch force under reduced and increased sensations simulated using cotton and nitrile gloves. The data were analysed using the analysis of variance via Minitab 16. Results show that the pinch force exerted for reduced sensations is higher than that of increased sensations because the reduced friction increased skin-object slippages, which caused participants to spontaneously increase their force to prevent slippages. This study serves as a guideline to potentially improve the design of objects operated with pinch grips to be safe and suitable for manual, sedentary or general tasks.

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Investigation of Grip Force, Normal Force, Contact Area, Hand Size, and Handle Size for Cylindrical Handles

Abstract: The quantitative relationships described in this paper can be used in the design of objects and hand tools to determine optimal handle sizes for maximizing grip force, total normal force, or contact area.

Cited by 127 publications

References 15 publications

Investigating interrelationships between Lower Palaeolithic stone tool effectiveness and tool user biometric variation: implications for technological and evolutionary changes

Investigating interrelationships between Lower Palaeolithic stone tool effectiveness and tool user biometric variation: implications for technological and evolutionary changes

Usability Validation of an Ergonomic Inward Directional Screwdriver for Enhanced Musculoskeletal Comfort

Influences of Tactile Sensation on Pinch Force under Loaded and Unloaded Conditions

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