AI Article Synopsis
- The study aimed to analyze the viscous properties of human muscle during plantarflexion using 17 subjects with an ankle ergometer for isometric contractions and isokinetic movements.
- Sinusoidal oscillations allowed for the creation of Bode diagrams that helped determine damping and viscous coefficients, while isokinetic movements revealed a torque-velocity relationship showing that torque decreases as angular velocity increases.
- The findings indicated that the damping coefficient from Bode diagrams (Bbode) was the lowest viscous parameter, suggesting a distinction between muscle cross-bridge viscosity and the mechanical damping of passive muscle structures.
Article Abstract
The purpose of this study was to determine viscous properties of human muscle during plantarflexion efforts. Experiments were performed on 17 subjects with an ankle ergometer allowing sinusoidal oscillations during isometric contractions and isokinetic movements. Sinusoidal oscillations led to the expression of (i) Bode diagrams of the musculo-articular system allowing the determination of a damping coefficient (Bbode); and (ii) a viscous coefficient (Bsin) using an adaptation of Hill's equation to sinusoidal oscillations. Isokinetic movements led to torque-velocity relationships. They showed a fall in torque associated to an increase in angular velocity what was quantified by calculating a damping coefficient (Biso). Both experiments gave consistent results indicating that Bbode was the lowest viscous parameter. This difference is discussed in terms of (i) "analog" viscosity originating from muscle cross-bridges; and (ii) real mechanical damping of passive structures.
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| http://dx.doi.org/10.1016/s0021-9290(99)00039-1 | DOI Listing |
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