Rate of force development: methodological issues - Dr. Maffiuletti скачать в хорошем качестве

Rate of force development: methodological issues - Dr. Maffiuletti

Invited Session "Rate of force development: methodological, physiological and practical issues" Rate of force development: methodological issues Maffiuletti, N.A. Schulthess Clinic The rate of rise in contractile force at the onset of an explosive voluntary contraction, better known as the rate of force development (RFD), is commonly measured in one of three ways: (1) as the highest value from the first derivative of the joint torque-time curve (peak RFD), (2) as the ratio between Deltatorque and Deltatime at predetermined intervals (RFD 0-50 to 0-250 ms) and/or as the corresponding area (impulse) beneath the torque-time curve, (3) as the RFD-scaling factor relationship using the peak RFD (scaled to MVC) recorded during short ballistic contractions at various submaximal levels plotted against MVC torque. The EMG counterpart of RFD, the rate of EMG rise (DeltaEMG/Deltatime), could also be recorded to characterize rapid muscle activation at the onset of a voluntary contraction. Besides voluntary actions, rate of force development can be quantified from electrically-evoked torque responses, which improve the reliability of RFD assessment (compared to voluntary contractions) and offer insights into the peripheral contractile determinants of RFD. Interestingly, electrically-evoked RFD largely exceeds voluntary RFD. The purpose of this talk is to present an overview of the main methodological issues in RFD quantification, which include measuring principles, considerations on the validity and reliability of RFD assessments, and recommendations for future applications in clinical and research settings.