Document Detail


The effect of handhold orientation, size, and wearing gloves on hand-handhold breakaway strength.
MedLine Citation:
PMID:  22768636     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: The aim of this study was to quantify the effect of handhold orientation, size (diameter), and wearing a glove on the maximum breakaway strength between a hand and handhold.
BACKGROUND: Manual breakaway strength is known to be greatly reduced for vertical compared with horizontal handholds, but oblique orientations have yet to be studied.
METHOD: For this study, 12 young adults (6 female) attempted to hold on to fixed overhead cylindrical handholds with one hand in low-speed simulated falls as forces on the handhold were recorded in two experimental designs. Breakaway strength was measured for (a) three different-sized cylinders in four orientations while the participants were using the dominant hand and (b) a single-sized cylinder in four orientations while the participants were bare-handed or wearing a glove on the nondominant hand.
RESULTS: Handhold orientation (p < .001), handhold diameter (p < .001), and wearing gloves (p < .001) significantly affected breakaway strength. Breakaway strength increased 75% to 94% as the orientation of the handhold was moved from vertical to horizontal. Breakaway strength decreased 8% to 13% for large-diameter (51-mm) handholds as compared with smaller diameters (22 mm to 32 mm), depending on orientation. Gloves may increase or decrease the ability to hang on depending on interface friction; greater friction increased breakaway force.
CONCLUSION: Handles oriented perpendicular to the pull direction and high-friction gloves provide the greatest breakaway strength. Smaller handhold diameters than predicted by grip strength afford greater capability in these orientations.
APPLICATION: These insights can be used to design handholds that increase the ability to support one's body weight and reduce the effort needed to pull or lift heavy items.
Authors:
Justin G Young; Charles B Woolley; James A Ashton-Miller; Thomas J Armstrong
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Publication Detail:
Type:  Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Human factors     Volume:  54     ISSN:  0018-7208     ISO Abbreviation:  Hum Factors     Publication Date:  2012 Jun 
Date Detail:
Created Date:  2012-07-06     Completed Date:  2012-08-02     Revised Date:  2013-06-14    
Medline Journal Info:
Nlm Unique ID:  0374660     Medline TA:  Hum Factors     Country:  United States    
Other Details:
Languages:  eng     Pagination:  316-33     Citation Subset:  IM; S    
Affiliation:
Department of Environmental Health, Harvard School of Public Health, 3rd Floor East, Area 49, Landmark Center, 401 Park Dr., Boston, MA 02215, USA. jgyoung@hsph.harvard.edu
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MeSH Terms
Descriptor/Qualifier:
Adult
Biomechanics
Equipment Design
Female
Gloves, Protective*
Hand / physiology*
Hand Strength*
Humans
Male
Muscle Strength* / physiology
Muscle Strength Dynamometer
Young Adult
Grant Support
ID/Acronym/Agency:
P30 AG024824/AG/NIA NIH HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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