Effect of Elliptic Handle Shape on Grasping Strategies, Grip Force Distribution, and Twisting Ability

Details

• Journal Article:
  Ergonomics
• Personal Author:
  Armstrong, Thomas J. ; Seo, Na Jin
• Description:
  A generic torque model for various handle shapes has been developed and evaluated using experimental data. Twelve subjects performed maximum isometric torques using circular and elliptic cylinders in medium and large sizes (circular: r = 25.4, 38.1 mm; elliptic: semi-major/minor axes = 30.9/19.3, 47.1/27.8 mm) finished with aluminium and rubber, in two opposite directions. Torque, grip force distribution, and finger position were recorded. Maximum torques were 25%, 7%, and 31% greater for the elliptic, large-size, and rubber-finished cylinders than for the circular, medium-size, and aluminium-finished cylinders, respectively. Greater torque for the elliptic cylinders was associated with 58% greater normal force that the subjects could generate for the elliptic than circular cylinders. The model suggests that greater torques for the large-size and rubber cylinders are related to long moment arms and greater frictional coupling at the hand-cylinder interface, respectively. Subjects positioned their hands differently depending on torque direction to maximise their normal force and torque generation. Statement of Relevance: Desirable handle features for torque generation may be different from those for grip only. Design of handles per advantageous handle features (e.g., shape, size, and surface) may help increase people's torque strength and contribute to increased physical capacity of people. [Description provided by NIOSH]
• Subjects:
  Biomechanical Phenomena Equipment Design Ergonomics Hand Hand Strength Models, Biological Musculoskeletal System Occupational Health Safety Torque
• Keywords:
  Author Keywords: Friction; Torque Direction; Normal Force Distribution; Moment Arm Biomechanics; Equipment Design; Ergonomics; Force; Upper Extremities; Body Mechanics;
• Source:
  Ergonomics 2011 Oct; 54(10):961-970
• ISSN:
  0014-0139
• Pubmed ID:
  21973007
• Pubmed Central ID:
  PMC8856563
• Document Type:
  Text
• Funding:
  T42 OH008455/OH/NIOSH CDC HHSUnited States/
• Genre:
  Journal Article
• Place as Subject:
  Michigan ; OSHA Region 5 ; Wisconsin
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  20 pdf pages
• Volume:
  54
• Issue:
  10
• NIOSHTIC Number:
  nn:20065855
• Contact Point Address:
  N.J. Seo, Department of Industrial Engineering, University of Wisconsin-Milwaukee, 3200 N. Cramer St., Milwaukee, WI, 53211, USA
• Email:
  seon@uwm.edu
• Federal Fiscal Year:
  2012
• Performing Organization:
  University of Michigan, Ann Arbor
• Peer Reviewed:
  True
• Collection(s):
  National Institute for Occupational Safety and Health CDC Public Access
• Main Document Checksum:
  urn:sha-512:6a3453f14fd267f39bcf7215785380c2bfe1fa4068c261427eec4290f31cf551809ce66d54ef55fb062c84df1bbd47fbb47ceb27129cb7c39de5695be15428c7
• Download URL:
  https://stacks.cdc.gov/view/cdc/114603/cdc_114603_DS1.pdf
• File Type:
  [PDF - 1020.88 KB ]