Virtual Poster Session

Welcome to the Virtual Poster Session, a new and powerful tool for networking and information exchange. Here you can share your work, search though the poster library, and start a dialogue with others in your field. Each uploaded poster that pertains to force measurement and testing can currently be used to apply for an academic travel scholarship; please see the Scholarships page for application details and deadlines.

Residual Force Enhancement in Context of Everyday Human Movement

Conference: ISB Brasil 2013
Abstract:

When an active muscle is stretched, the resulting post-eccentric steady-state force is known to be greater than the isometric force at the corresponding muscle length. The aim of our research was to clarify if residual force enhancement (RFE) is relevant for voluntary human muscle action in everyday like scenarios. Therefore 13 healthy subjects participated in our study and had to perform bilateral leg extensions using a motor-driven leg press dynamometer, measuring external reaction forces (Fext) as well as activity of 9 lower extremity muscles. In addition, ankle (Ma) and knee (Mk) joint torque were calculated using inverse dynamics. Subjects performed isometric and isometric-eccentric-isometric contractions (20° stretch, ω=60°/s) at 30% of maximum voluntary activation. Visual feedback of VL muscle activation was given to control submaximal muscle action. We did not find differences in VL activation level between contraction conditions and time points. Mean VL activity ranged between 29.1 ± 2.2% and 29.8±2.5% MVA. We found significantly enhanced Fext (p < 0.002) as well as joint torques in knee (p < 0.002) and ankle joint (p < 0.033) for all instances in time. In summary RFE seems to be relevant in everyday like human motion.


Listed In: Biomechanics, Sports Science,
Tagged In: Electromyography, multi-join, residual force enhancemenet, submaximal

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