![]() 2002 Dec 133(4):1101-7.Įffects of exercise on the biomechanical, biochemical and structural properties of tendons. Here is the citation from PubMed:Ĭomp Biochem Physiol A Mol Integr Physiol. These authors appear not to advance the issue since then. ![]() In the meanwhile, the immediate issue of adaptive properties of tendons has been reviewed recently. Deep-etch EM's of non-overlap fibers disclosed abundant structures (about 75 A) wide Non-overlap fibrils, when treated with elastase, released A-segments which retain three-dimensional coherency. Treatment of non-overlap fibers with a high ionic strength pyrophosphate myosin solvent caused a large drop in passive tension and stiffness, but no change in SL was detected nor was myofibril continuity detectably affected. Extreme stretch of fibers caused the thick filaments to strain several-fold. Equatorial X-ray measurements showed that stretching relaxed skinned muscles squeezed the thick filaments closer this radial compression continued beyond filament overlap. Unlike actin, these filaments did not become decorated by myosin S-1. In the gap between them could be seen filaments, 40-50 A in diameter, connected to the thick filament ends. ![]() Ned and freeze-fracture/deep-etch specimens) of non-overlap fibers showed orderly fibril structure with clear separation of A- and I-bands. Passive tension phasically exceeded 3 X 10(5) N/M2. Isolated myofibrils (mechanically-skinned and detergent-treated frog semitendinosus fibers) when stretched progressively showed exponentially-increasing passive tension which did not disappear when filament overlap was exceeded, but continued to rise. C-filaments would act as the parallel elastic element and transmit the passive tension to the thick filaments. The proposal includes: connecting filaments (C-filaments) which connect the ends of each thick filament to the neighboring Z-lines, core filaments which support the myosin of the thick filament and which attach to the C-filaments, and side-struts which bind the thick filaments together along their length and restrict their radial movement. This report concerns structural forces in resting muscle and proposes three additions to the sliding filament model to account for these mechanical properties. Magid A, Ting-Beall HP, Carvell M, Kontis T, Lucaveche C. This is an abstract of our ‘84 paper:Ĭonnecting filaments, core filaments, and side-struts: a proposal to add three new load-bearing structures to the sliding filament model. My structural, mechanical, and analytic approach applies rather to all muscles in all creatures. He also focuses on the galloping or bounding gait of long-legged mammals (think prong-horn antelope or kangaroo). This likely limits the generality of his approach. In the meantime.Ī first point: R McNeill Alexander, an authority on “tendon stretch” appears to be unaware of the three “new” elastic structures within the sarcomere itself that we proposed and justified back in 1984. This effort will take many months to complete. ![]() This effort will obviously entail more than an email will accommodate since I have many data and thoughts to pull together. ![]() Saw the thread with the peculiar subject line and it has provoked me to write a review of muscle elasticity at long last from the sarcomere level up to the whole body level. Just back from a delightful minivacation (2 nights, 1 day) to Charleston SC.
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