Introduction of dynamic rate-of-force development scaling factor in progressive drop jumps

Nejc Šarabon (Author), Olivera M. Knezevic (Author), Dragan M. Mirkov (Author), Darjan Smajla (Author)

Abstract

Rapid force generation across submaximal levels has been evaluated with the rate of force development scaling factor (RFD-SF) in different isometric tasks, while such measurement was still not verified in dynamic tasks. Our study was designed to evaluate the feasibility of the RFD-SF in dynamic drop jump (DJ) task (RFD-SFDJ). A total of 55 young athletes performed isometric plantarflexion at different submaximal intensities and 60 DJs (6 different drop heights). For each participant we calculated linearity (r2 ) and slope in isometric task (RFD-SFPF), eccentric part of DJ (RFD-SFDJ-ECC) and concentric part of DJ (RFD-SFDJ-CON), as well as average jump height (DJH) from each drop height. Our results revealed strong linear force-RFD relationship for isometric plantarflexion (r2 = 0.90 % 0.06), eccentric (r2 = 0.87 % 0.09) and concentric phase of DJ (r2 = 0.80 % 0.18). Significant moderate positive correlations were calculated between RFD-SFPF and RFD-SFDJ-ECC (r = 0.311, p < 0.05) and small negative correlations between RFD-SFDJ-CON and RFD-SF (r = -0.276, p < 0.05). Significant positive moderate correlations were seen only between RFD-SFDJ-ECC and DJH from 10 cm (r = 0.459, p < 0.001) and 15 cm (r = 0.423, p < 0.01). This is the first study to introduce and confirm that RFD-SFDJ can be obtained from the multi-joint tasks (60 jumps) and still provide acceptable reliability and linear relationship. Furthermore, RFD-SFDJ may have greater practical application than RFD-SF assessed under the isometric conditions. This verification of RFD-SFDJ opens opportunities for further research regarding its practical application.

Keywords

explosive strength;stretch-shortening cycle;plyometric;ankle;isometric;

Data

Language:	English
Year of publishing:	2020
Typology:	1.01 - Original Scientific Article
Organization:	UP FVZ - College of Health Care Izola
UDC:	796.012.11
COBISS:	24332035
ISSN:	0021-9290
Views:	1765
Downloads:	70
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary keywords:	eksplozivna moč;cikel raztezanja-krčenja;pliometrija;gleženj;izometrično;
Pages:	str. 1-7
Issue:	ǂVol. ǂ110
Chronology:	Sep. 2020
DOI:	10.1016/j.jbiomech.2020.109980
ID:	15493623