The Effect of Handle Friction and Inward or Outward Torque on Maximum Axial Push Force

Details

• Personal Author:
  Armstrong TJ ; Ashton-Miller JA ; Chaffin, Don B. ; Seo NJ
• Description:
  Objective: To investigate the relationship among friction, applied torque, and axial push force on cylindrical handles. Background: We have earlier demonstrated that participants can exert greater contact force and torque in an "inward" movement of the hand about the long axis of a gripped cylinder (wrist flexion/forearm supination) than they can in an "outward" hand movement. Method: Twelve healthy participants exerted anteriorly directed maximum push forces along the long axis of aluminum and rubber handles while applying deliberate inward or outward torques, no torque (straight), and an unspecified (preferred) torque. Results: Axial push force was 12% greater for the rubber handle than for the aluminum handle. Participants exerted mean torques of 1.1, 0.3, 2.5, and -2.0 Nm and axial push forces of 94, 85, 75, and 65 N for the preferred, straight, inward, and outward trials, respectively. Left to decide for themselves, participants tended to apply inward torques, which were associated with increased axial push forces. Conclusion: Axial push force was limited by hand-handle coupling - not the whole body's push strength. Participants appeared to intuitively know that the application of an inward torque would improve their maximum axial push force. Axial push forces were least when a deliberate torque was requested, probably because high levels of torque exertions interfered with the push. Application: A low-friction handle decreases maximum axial push force. It should be anticipated that people will apply inward torque during maximum axial push. [Description provided by NIOSH]
• Subjects:
  Biomechanical Phenomena Ergonomics Musculoskeletal System Occupational Health Safety
• Keywords:
  Biomechanical Modeling Biomechanics Force Upper Extremities
• ISSN:
  0018-7208
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Michigan ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  227-236
• Volume:
  50
• Issue:
  2
• NIOSHTIC Number:
  nn:20057834
• Citation:
  Hum Factors 2008 Apr; 50(2):227-236
• Contact Point Address:
  Na Jin Seo, 345 E. Superior St., Suite 1406, Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL 60611
• Email:
  n-seo@northwestern.edu
• Federal Fiscal Year:
  2008
• Performing Organization:
  University of Michigan, Ann Arbor
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Human Factors
• End Date:
  20280630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:5e8e9e8eb56b659ecd17fb3b72c8e7d4e8fa88c2154199a6424eaf2b8e9937af5fe0331154aac28b7eab901614a43a30090309913637f1b08ce00f01d0e38e34
• Download URL:
  https://stacks.cdc.gov/view/cdc/215050/cdc_215050_DS1.pdf
• File Type:
  [PDF - 254.94 KB ]