Trunk Kinematics and Trunk Muscle Activity During a Rapidly Applied Load

Details

• Personal Author:
  Andersson GB ; Corcos DM ; Lavender SA ; Thomas JS ; Andersson GB ; Corcos DM ; Lavender SA ; Thomas JS
• Description:
  This study investigated the trunk kinematics and electromyographic (EMG) activity of eight trunk muscles when "expected" and "unexpected" loads were applied directly to the torso. Twenty individuals (mean age: 25.1 yr; range 20-33 yr) participated in this mixed model study in which gender was the between-subjects factor, and expectancy and symmetry of the applied load were within-subject factors. The sudden load was delivered to the subject via a cable attached to a thoracic harness and motion was restricted to the lumbar spine by strapping the pelvis to a rigid fixation apparatus. Surface EMG was recorded bilaterally from the longissimus thoracis (LGT), erector spinae (ERS), rectus abdominis (RAB) and the external obliques (EXO). Trunk kinematics were measured with a Lumbar Motion Monitor. During expected loading conditions, the peak muscle activity was reduced for the RAB and EXO bilaterally, and for the ERS(R) (p < 0.01) relative to the unexpected conditions. Conversely, the normalized area of EMG activity prior to the onset of load was increased for the ERS and EXO bilaterally, and for the RAB(R) (p < 0.05) during an expected loading event. Trunk motion in the sagittal and frontal planes was reduced during expected loading. Activation of the trunk muscles just prior to a rapid loading event increases trunk stiffness, decreasing trunk displacement and peak muscle activity. [Description provided by NIOSH]
• Subjects:
  Mining Occupational Health Safety
• Keywords:
  Age-factors Age-groups Biomechanics Demographic-characteristics Models Muscles Sex-factors
• ISSN:
  1050-6411
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article ; Journal Article
• Place as Subject:
  Illinois ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH) ; National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health ; Workplace Safety & Health
• Location:
  North America ; North America
• Pages in Document:
  215-225
• Volume:
  8
• Issue:
  4
• NIOSHTIC Number:
  nn:20030587
• Citation:
  J Electromyogr Kinesiol 1998 Aug; 8(4):215-225
• Federal Fiscal Year:
  1998
• Peer Reviewed:
  True
• Source Full Name:
  Journal of Electromyography and Kinesiology
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:54a87026e6255978e80e4b3c4dc5056aee8e2d4e51ad1948349518f10be60411cfc0a2a2b680573d311bda2003d4ab209a8be1bb7932a52ccc613e0a8bb9a3ac
• Download URL:
  https://stacks.cdc.gov/view/cdc/191143/cdc_191143_DS1.pdf
• File Type:
  [PDF - 782.38 KB ]