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Mechanical and Magnetic Resonance Imaging Changes Following Eccentric or Concentric Exertions



Details

  • Personal Author:
  • Description:
    BACKGROUND: Prior work has shown that changes in mechanical parameters and magnetic resonance imaging parameters occur following submaximal eccentric activity but it is unclear whether similar changes occur following submaximal concentric activity. This study compared mechanical response parameters and MRI relaxation parameters following submaximal concentric or eccentric exertions. METHODS: This single site, randomized study investigated in vivo changes in human upper limb dynamic mechanical properties following exposure to short term repetitive submaximal eccentric or concentric exertions. Eighteen subjects were assigned to either an eccentric or concentric group and exercised for 30 min at 50% of isometric forearm maximum voluntary contraction. Changes in strength, symptom intensity, magnetic resonance imaging T2 relaxation measurements, which are indicative of edema, and dynamic mechanical parameters (stiffness, effective mass, and damping) were ascertained prior to exercise, 1h after, and 24h later. FINDINGS: Strength decreased following exercise (P<0.01), however only the eccentric exercise group exhibited a reduction in mechanical stiffness (55%, P<0.01) and damping (31%, P<0.05), and an increase (17%, P<0.05) in magnetic resonance imaging T2 relaxation time. INTERPRETATION: The changes in mechanical parameters and magnetic resonance imaging findings following repetitive submaximal eccentric activity could negatively impact the ability of the arm to react to rapid forceful loading during repetitive industrial work activities and may result in increased strain on the upper limb. Similar changes were not observed following concentric exercise. [Description provided by NIOSH]
  • Subjects:
  • Keywords:
  • ISSN:
    0268-0033
  • Document Type:
    Text
  • Funding:
    Grant
  • Genre:
    Journal Article
  • Place as Subject:
  • CIO:
    National Institute for Occupational Safety and Health (NIOSH)
  • Topic:
    Workplace Safety & Health
  • Location:
    North America
  • Volume:
    23
  • Issue:
    7
  • NIOSHTIC Number:
    nn:20034628
  • Citation:
    Clin Biomech 2008 Aug; 23(7):961-968
  • Contact Point Address:
    Robert G. Radwin, Department of Biomedical Engineering, University of Wisconsin, Madison, WI 53706
  • Email:
    radwin@bme.wisc.edu
  • Federal Fiscal Year:
    2008
  • Performing Organization:
    University of Wisconsin, Madison
  • Peer Reviewed:
    True
  • Start Date:
    20020930
  • Source Full Name:
    Clinical Biomechanics
  • End Date:
    20060929
  • Collection(s):
  • Main Document Checksum:
    urn:sha-512:589649b3709519591bbcee1950164bbbc190ebb896c6e47741dfc52152170a3e1fe10187823f005f63e81f6b92cffccdd1bab61bbb54f12f5868e2f911729c37
  • Download URL:
  • File Type:
    Filetype[PDF - 4.90 MB ]
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