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Constrained tibial vibration in mice: a method for studying the effects of vibrational loading of bone
- Source :
- Journal of biomechanical engineering. 130(4)
- Publication Year :
- 2008
-
Abstract
- Vibrational loading can stimulate the formation of new trabecular bone or maintain bone mass. Studies investigating vibrational loading have often used whole-body vibration (WBV) as their loading method. However, WBV has limitations in small animal studies because transmissibility of vibration is dependent on posture. In this study, we propose constrained tibial vibration (CTV) as an experimental method for vibrational loading of mice under controlled conditions. In CTV, the lower leg of an anesthetized mouse is subjected to vertical vibrational loading while supporting a mass. The setup approximates a one degree-of-freedom vibrational system. Accelerometers were used to measure transmissibility of vibration through the lower leg in CTV at frequencies from 20 Hz to 150 Hz. First, the frequency response of transmissibility was quantified in vivo, and dissections were performed to remove one component of the mouse leg (the knee joint, foot, or soft tissue) to investigate the contribution of each component to the frequency response of the intact leg. Next, a finite element (FE) model of a mouse tibia-fibula was used to estimate the deformation of the bone during CTV. Finally, strain gages were used to determine the dependence of bone strain on loading frequency. The in vivo mouse leg in the CTV system had a resonant frequency of 60 Hz for +/-0.5 G vibration (1.0 G peak to peak). Removing the foot caused the natural frequency of the system to shift from 60 Hz to 70 Hz, removing the soft tissue caused no change in natural frequency, and removing the knee changed the natural frequency from 60 Hz to 90 Hz. By using the FE model, maximum tensile and compressive strains during CTV were estimated to be on the cranial-medial and caudolateral surfaces of the tibia, respectively, and the peak transmissibility and peak cortical strain occurred at the same frequency. Strain gage data confirmed the relationship between peak transmissibility and peak bone strain indicated by the FE model, and showed that the maximum cyclic tibial strain during CTV of the intact leg was 330+/-82microepsilon and occurred at 60-70 Hz. This study presents a comprehensive mechanical analysis of CTV, a loading method for studying vibrational loading under controlled conditions. This model will be used in future in vivo studies and will potentially become an important tool for understanding the response of bone to vibrational loading.
- Subjects :
- Male
Frequency response
Materials science
Biomedical Engineering
medicine.disease_cause
Mechanotransduction, Cellular
Models, Biological
Vibration
Article
Weight-bearing
Weight-Bearing
Mice
Physiology (medical)
Physical Stimulation
medicine
Animals
Computer Simulation
Tibia
Transmissibility (structural dynamics)
Strain gauge
business.industry
Natural frequency
Structural engineering
Equipment Design
Equipment Failure Analysis
Mice, Inbred C57BL
Deformation (engineering)
business
Biomedical engineering
Subjects
Details
- ISSN :
- 01480731
- Volume :
- 130
- Issue :
- 4
- Database :
- OpenAIRE
- Journal :
- Journal of biomechanical engineering
- Accession number :
- edsair.doi.dedup.....9876477f2c28447aac0805197e5a5249