Force Deficits After Repeated Stretches of Activated Skeletal Muscles in Female and Male Rats

Details

• Personal Author:
  Stauber WT ; Willems ME
• Description:
  Force deficits after stretches of activated plantar flexor muscles were measured in six male Sprague-Dawley rats (285 +/- 10 g, age 62 +/- 4 days, mean +/- SE) and compared with six age-matched (193 +/- 6 g, age 67 +/- 3 days) and six weight-matched female rats (273 +/- 7 g, age 141 +/- 9 days). Twenty stretches, imposed on isometric contractions at 90 degrees (0.2 ms pulse duration, 80 Hz, 5.4 +/- 0.3 V, duty cycle 0.006), were produced by ankle rotation from 90 to 40 degrees. Before the stretch protocol, weight-matched groups had similar isometric forces at an ankle position of 90 degrees at 5, 10, 20, 40, 60 and 80 Hz but forces were lower for age-matched females. For all groups, normalized force-frequency relationships were similar. During the stretch protocol, deficits for isometric force at 90 degrees and peak stretch force at 40 degrees with stretch number were similar for all groups. One hour after the stretches, isometric force deficits at 90 degrees at 40, 60 and 80 Hz were larger for females in weight-matched groups (e.g. 80 Hz, female: 47.8 +/- 1.7%; male: 41.1 +/- 1.7%; P < 0.05), perhaps because of a difference in age (P < 0.05). For age-matched groups, isometric force deficits at 90 degrees were similar at all frequencies. The susceptibility for force deficits by stretches of activated skeletal muscles was not gender-dependent for 2-month-old rats. [Description provided by NIOSH]
• Subjects:
  Air Movements Air Pollution Air Pollution, Indoor Air Pressure Dust Filtration Laboratories Manufacturing And Industrial Facilities Mining Occupational Exposure Occupational Health Particulate Matter Safety Silicon Dioxide

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• Keywords:
  Animals Animal Studies Fatigue Laboratory Animals Muscles Musculoskeletal System Skeletal System
• ISSN:
  0001-6772
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  63-67
• Volume:
  172
• Issue:
  1
• NIOSHTIC Number:
  nn:20029526
• Citation:
  Acta Physiol Scand 2001 May; 172(1):63-67
• Contact Point Address:
  Department of Biochemistry, P.O. Box 9142, West Virginia University Health Sciences Center, Morgantown, WV 26506-9142
• Federal Fiscal Year:
  2001
• NORA Priority Area:
  Disease and Injury: Musculoskeletal Disorders of the Upper Extremities
• Performing Organization:
  West Virginia University, Morgantown, West Virginia
• Peer Reviewed:
  True
• Start Date:
  19920101
• Source Full Name:
  Acta Physiologica Scandinavica
• End Date:
  20050531
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:63c34085aabc06d8689f1ff9f1aa50479a60f34fc3f036c60bf76526db8d346b78bd0ca49852e1b4d27649a5167e45d4541a85f598cbec1dbbeca3bff49412b2
• Download URL:
  https://stacks.cdc.gov/view/cdc/190482/cdc_190482_DS1.pdf
• File Type:
  [PDF - 154.93 KB ]