caa a22 4500 445353619 CHVBK 20180317142852.0 cr unu---uuuuu 170323e20110701xx s 000 0 eng 10.1007/s00221-011-2735-7 doi (NATIONALLICENCE)springer-10.1007/s00221-011-2735-7 The rate of force development scaling factor (RFD-SF): protocol, reliability, and muscle comparisons [Elektronische Daten] [Maria Bellumori, Slobodan Jaric, Christopher Knight] Performing a set of isometric muscular contractions to varied amplitudes with instructions to generate force most rapidly reveals a strong linear relationship between peak forces (PF) achieved and corresponding peak rates of force development (RFD). The slope of this relationship, termed the RFD scaling factor (RFD-SF), quantifies the extent to which RFD scales with contraction amplitude. Such scaling allows relative invariance in the time required to reach PF regardless of contraction size. Considering the increasing use of this relationship to study quickness and consequences of slowness in older adults and movement disorders, our purpose was to further develop the protocol to measure RFD-SF. Fifteen adults (19-28years) performed 125 rapid isometric contractions to a variety of force levels in elbow extensors, index finger abductors, and knee extensors, on 2days. Data were used to determine (1) how the number of pulses affects computation of the RFD-SF, (2) day-to-day reliability of the RFD-SF, and (3) the nature of RFD-SF differences between diverse muscle groups. While sensitive to the number of pulses used in its computation (P<.05), RFD-SF was reliable when computed with >50 pulses (ICC>.7) and more so with 100-125 pulses (ICC=.8-.92). Despite differences in size and function across muscles, RFD-SF was generally similar (i.e., only 8.5% greater in elbow extensors than in index finger abductors and knee extensors; P=.049). Results support this protocol as a reliable means to assess how RFD scales with PF in rapid isometric contractions as well as a simple, non-invasive probe into neuromuscular health. Springer-Verlag, 2011 Neuromuscular nationallicence Physical function nationallicence Measurement nationallicence Assessment nationallicence Power nationallicence Motor control nationallicence Muscle nationallicence Bellumori Maria Department of Kinesiology and Applied Physiology, University of Delaware, 541 S. College Ave, 19716, Newark, DE, USA aut Jaric Slobodan Department of Kinesiology and Applied Physiology, University of Delaware, 541 S. College Ave, 19716, Newark, DE, USA aut Knight Christopher Department of Kinesiology and Applied Physiology, University of Delaware, 541 S. College Ave, 19716, Newark, DE, USA aut Experimental Brain Research Springer-Verlag 212/3(2011-07-01), 359-369 0014-4819 212:3<359 2011 212 221 https://doi.org/10.1007/s00221-011-2735-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00221-011-2735-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bellumori Maria Department of Kinesiology and Applied Physiology, University of Delaware, 541 S. College Ave, 19716, Newark, DE, USA aut NATIONALLICENCE 700 1- Jaric Slobodan Department of Kinesiology and Applied Physiology, University of Delaware, 541 S. College Ave, 19716, Newark, DE, USA aut NATIONALLICENCE 700 1- Knight Christopher Department of Kinesiology and Applied Physiology, University of Delaware, 541 S. College Ave, 19716, Newark, DE, USA aut NATIONALLICENCE 773 0- Experimental Brain Research Springer-Verlag 212/3(2011-07-01), 359-369 0014-4819 212:3<359 2011 212 221 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer