Joint contribution to fingertip movement during a number entry task: an application of Jacobian matrix

Details

• Personal Author:
  Buchholz B ; Dennerlein, Jack T. ; Katz JN ; Qin J ; Trudeau M ; Xu X
• Description:
  Upper extremity kinematics during keyboard use is associated with musculoskeletal health among computer users; however, specific kinematics patterns are unclear. This study aimed to determine the dynamic roles of the shoulder, elbow, wrist and metacarpophalangeal (MCP) joints during a number entry task. Six subjects typed in phone numbers using their right index finger on a stand-alone numeric keypad. The contribution of each joint of the upper extremity to the fingertip movement during the task was calculated from the joint angle trajectory and the Jacobian matrix of a nine-degree-of-freedom kinematic representation of the finger, hand, forearm and upper arm. The results indicated that in the vertical direction where the greatest fingertip movement occurred, the MCP, wrist, elbow (including forearm) and shoulder joint contributed 10.2%, 55.6%, 27.7% and 6.5%, respectively, to the downward motion of the index finger averaged across subjects. The results demonstrated that the wrist and elbow contribute the most to the fingertip vertical movement, indicating that they play a major role in the keying motion and have a dynamic load beyond maintaining posture. [Description provided by NIOSH]
• Subjects:
  Biomechanical Phenomena Computers Men Musculoskeletal System Occupational Health Safety Women
• Keywords:
  Biomechanics Extremities Humans Musculoskeletal-system Physical-capacity Physical-reactions Physiological-factors Physiology Posture Statistical-analysis
• ISSN:
  1065-8483
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Massachusetts ; OSHA Region 1
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  338-342
• Volume:
  30
• Issue:
  2
• NIOSHTIC Number:
  nn:20046225
• Citation:
  J Appl Biomech 2014 Apr; 30(2):338-342
• Federal Fiscal Year:
  2014
• Performing Organization:
  Harvard University School of Public Health
• Peer Reviewed:
  True
• Start Date:
  20070301
• Source Full Name:
  Journal of Applied Biomechanics
• End Date:
  20120228
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:77267e3f5c3c60a93669753313bcb534234111d84f588c4572733d015cb5d4a41bb8035f62cd22fe06c1c9cb58340fce16fefbe773be587a00b142ed899fd28a
• Download URL:
  https://stacks.cdc.gov/view/cdc/201340/cdc_201340_DS1.pdf
• File Type:
  [PDF - 1.85 MB ]