Mechanical loading, damping, and load-driven bone formation in mouse tibiae

Details

• Personal Author:
  Akkus O ; Ayoub R ; Bhattacharya, Amit ; Dodge T ; Robling A ; Wanis M ; Watts NB ; Yokota H ; Zhao L
• Description:
  Mechanical loads play a pivotal role in the growth and maintenance of bone and joints. Although loading can activate anabolic genes and induce bone remodeling, damping is essential for preventing traumatic bone injury and fracture. In this study we investigated the damping capacity of bone, joint tissue, muscle, and skin using a mouse hindlimb model of enhanced loading in conjunction with finite element modeling to model bone curvature. Our hypothesis was that loads were primarily absorbed by the joints and muscle tissue, but that bone also contributed to damping through its compression and natural bending. To test this hypothesis, fresh mouse distal lower limb segments were cyclically loaded in axial compression in sequential bouts, with each subsequent bout having less surrounding tissue. A finite element model was generated to model effects of bone curvature in silico. Two damping-related parameters (phase shift angle and energy loss) were determined from the output of the loading experiments. Interestingly, the experimental results revealed that the knee joint contributed to the largest portion of the damping capacity of the limb, and bone itself accounted for approximately 38% of the total phase shift angle. Computational results showed that normal bone curvature enhanced the damping capacity of the bone by approximately 40%, and the damping effect grew at an accelerated pace as curvature was increased. Although structural curvature reduces critical loads for buckling in beam theory, evolution apparently favors maintaining curvature in the tibia. Histomorphometric analysis of the tibia revealed that in response to axial loading, bone formation was significantly enhanced in the regions that were predicted to receive a curvature-induced bending moment. These results suggest that in addition to bone's compressive damping capacity, surrounding tissues, as well as naturally-occurring bone curvature, also contribute to mechanical damping, which may ultimately affect bone remodeling and bone quality. [Description provided by NIOSH]
• Subjects:
  Animals Biomechanical Phenomena Genetics Laboratories Musculoskeletal System Occupational Health Safety Skin
• Keywords:
  Animal-studies Author Keywords: Tibia Loading Biomechanics Body-burden Body-mechanics Body-regions Bone-structure Bone Remodeling Damping Genes Histomorphology Laboratory-animals Laboratory-testing Muscle-tissue Muscles Phase Shift Angle Physiology Skeletal-system Tissue-distribution Ulna Loading

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• ISSN:
  8756-3282
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Indiana ; Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  51
• Issue:
  4
• NIOSHTIC Number:
  nn:20042134
• Citation:
  Bone 2012 Oct; 51(4):810-818
• Contact Point Address:
  Hiroki Yokota, Biomedical Engineering, Indiana University Purdue University Indianapolis, 723 West Michigan Street, SL220C, Indianapolis, IN 46202, USA
• Federal Fiscal Year:
  2013
• Performing Organization:
  University of Cincinnati
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Bone
• End Date:
  20260630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:9cdaa2543334ccc7e8461fe23908d644ae86dee5e4fba95e5be928ef450681fcd7529385a9c5a1302034ecfaf9b01618c5cb5b2a6c9995dbb751cdfc241ed772
• Download URL:
  https://stacks.cdc.gov/view/cdc/194455/cdc_194455_DS1.pdf
• File Type:
  [PDF - 1.10 MB ]