This study quantified mechanical and structural responses to loading conditions at subtendon hierarchical levels. Tensile tests were performed at three strain rates on three groups of rabbit patellar tendon specimens. For each rate, tangent modulus (E) was computed from the stress-strain curves and the following structural responses were evaluated: (i) Area percent of collagen fibrils (FAR) and (ii) Skewness angle formed between proteoglycans and collagen fibrils. For 0.1%/s, 10%/s, and 70%/s, E was 48.8±20.3MPa, 64.7±29.3MPa, and 78.6±31.7MPa, respectively. For control, 0.1%/s, 10%/s, and 70%/s, the mean FAR was 0.7552±0.1476, 0.6628±0.1190, 0.6335±0.1013, and 0.6047±0.0384, respectively; and proteoglycan skewness angles were 14.70º±11.01º, 12.76º±10.13º, 15.08.0º±11.66º, and 16.68º±12.07º, respectively. For increased E, interfibrillar components had less time for effective fluid flow, energy dissipation, and structural rearrangement. The inverse relationship of FAR to strain rate may be due to broken fibrils and the Poisson effect. Proteoglycan skewness angle increase is likely due to stretched fibrils.
| Identifer | oai:union.ndltd.org:MSSTATE/oai:scholarsjunction.msstate.edu:td-5064 |
| Date | 13 December 2008 |
| Creators | Davis, Deborah D |
| Publisher | Scholars Junction |
| Source Sets | Mississippi State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
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