rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Quantifying the strain response in the rat tibia during simulated resistance training used as a disuse countermeasure
  name:
    name part: Jeffery, Jay Melvin
    name part: 1978-
    role:
      role term: creator
  name:
    name part: Bloomfield, Susan A.
    role:
      role term: thesis advisor.
  name:
    name part: Hogan, Harry A.
    role:
      role term: thesis advisor.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2008
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: electronic
    form: remote
  abstract: Disuse of weight bearing bones has been shown to cause bone loss. This poses a health concern for people exposed to microgravity, such as astronauts. Animal studies are used to study factors related to bone loss and countermeasures to prevent bone loss. This study used a hindlimb unloaded (HU) rat model to simulate microgravity and a muscle stimulation countermeasure to simulate resistive exercise. Uniaxial strain gages were implanted on the antero-medial aspect of the proximal tibia to measure the mechanical strain during a typical exercise session. In a separate but parallel study, the exercise was shown to be an effective countermeasure to disuse related bone loss. The current study sought to understand the loading of the bone during the exercise. To determine if the strain response changes during a protocol using this countermeasure, strains were measured on a group of weight bearing animals and a group that were hind limb unloaded and received the countermeasure for 21 days. Strain magnitudes and rates were considered and related to torques at the ankle joint. No significant differences in strain magnitudes were noted between the baseline control group and the hindlimb unloaded group that received the countermeasure. The two kinds of contractions used in an exercise session are isometric and eccentric. The isometric contractions are used to adjust the stimulation equipment for the eccentric contractions, which constitute the exercise. Peak strain levels during the isometric contractions ranged from 900 to 2200 microstrain while the eccentric were 38% lower and ranged from 600 to 1400. Eccentric strain rates were 62% lower than the isometric contractions strain rates. These results indicate that the strain environment during the isometric contractions may be causing more of the osteogenic response than the eccentric contractions, which have previously been thought to be the primary part of the countermeasure.
  note: by Jay Melvin Jeffery.
  note: "Major Subject: Mechanical Engineering"
  note: Title from author supplied metadata (automated record created on Oct. 13, 2008.)
  note: Vita.
  note: Abstract.
  note: Electronic resource.
  note: Mode of access: World Wide Web.
  note: System requirements: World Wide Web access and Adobe Acrobat Reader.
  note: M. S. Texas A&M University 2007.
  note: Includes bibliographical references.
  note: Text (M. S.).
  subject:
    topic: Major mechanical engineering
  subject:
    topic: Biomechanics
  subject:
    topic: Disuse
  subject:
    topic: Exercise
  subject:
    topic: Rat
  subject:
    topic: Muscle stimualtion
  subject:
    topic: Strain
  subject:
    topic: Tibia
  subject:
    topic: Bone
  subject:
    topic: Mechanics
  identifier: http://hdl.handle.net/1969.1/85851
  record info:
    record content source: TXA
    record creation date: 090216
    record change date: 20151110065940.0
    record identifier: in00002451689