Evaluation of Handle Design Characteristics in a Maximum Screwdriving Torque Task

Details

• Personal Author:
  Kong, Yong-Ku ; Krieg EF ; Lee SL ; Lowe, Brian D.
• Description:
  The purpose of this study was to evaluate the effects of screwdriver handle shape, surface material and workpiece orientation on torque performance, finger force distribution and muscle activity in a maximum screwdriving torque task. Twelve male subjects performed maximum screw-tightening exertions using screwdriver handles with three longitudinal shapes (circular, hexagonal and triangular), four lateral shapes (cylindrical, double frustum, cone and reversed double frustum) and two surfaces (rubber and plastic). The average finger force contributions to the total hand force were 28.1%, 39.3%, 26.5% and 6.2%, in order from index to little fingers; the average phalangeal segment force contributions were 47.3%, 14.0%, 20.5% and 18.1% for distal, middle, proximal and metacarpal phalanges, respectively. The plastic surface handles were associated with 15% less torque output (4.86 Nm) than the rubber coated handles (5.73 Nm). In general, the vertical workpiece orientation was associated with higher torque output (5.9 Nm) than the horizontal orientation (4.69 Nm). Analysis of handle shapes indicates that screwdrivers designed with a circular or hexagonal cross-sectional shape result in greater torque outputs (5.49 Nm, 5.57 Nm), with less total finger force (95 N, 105 N). In terms of lateral shape, reversed double frustum handles were associated with less torque output (5.23 Nm) than the double frustum (5.44 Nm) and cone (5.37 Nm) handles. Screwdriver handles designed with combinations of circular or hexagonal cross-sectional shapes with double frustum and cone lateral shapes were optimal in this study. [Description provided by NIOSH]
• Subjects:
  Ergonomics Musculoskeletal System Occupational Health Safety
• Keywords:
  Analytical-methods Analytical-processes Hand-tools Musculoskeletal-system Tools
• ISSN:
  0014-0139
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DART - Division of Applied Research and Technology
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  50
• Issue:
  9
• NIOSHTIC Number:
  nn:20032530
• Citation:
  Ergonomics 2007 Sep; 50(9):1404-1418
• Contact Point Address:
  BD Lowe, National Institute for Occupational Safety and Health, Division of Applied Research and Technology, Engineering and Physical Hazards Branch, 4676 Columbia Parkway, MS C-26, Cincinnati, OH 45226
• Email:
  blowe@cdc.gov
• Federal Fiscal Year:
  2007
• NORA Priority Area:
  Construction
• Peer Reviewed:
  True
• Source Full Name:
  Ergonomics
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:9efeac5cc00242a0b54be5f5fd45a7218e2ae4fa2c90448a112338a9c45f13f22df2a32bf8e2164ede2ef47baf45c817ffcb88fd7df0d346ebcf2f70cdd6bb0f
• Download URL:
  https://stacks.cdc.gov/view/cdc/186467/cdc_186467_DS1.pdf
• File Type:
  [PDF - 1.59 MB ]