Force–velocity relationship of leg extensors obtained from loaded and unloaded vertical jumps

Abstract

Purpose Resent research has suggested that loaded multi-joint movements could reveal a linear force-velocity (F-V) relationship. The aim of the present study was to evaluate the F-V relationship both across different types of vertical jumps and across different F and V variables. Methods Ten healthy subjects performed maximum various vertical jumps that were either loaded or unloaded by constant external forces of up to 30% of their body weight. Both the maximum and averaged F and V data were recorded. Results The observed F-V relationships proved to be strong (median correlation coefficients ranged .78-.93) and quasi-linear. Their F- and V-intercepts and the calculated maximum power (P) were highly reliable (.85<ICC<.98), while their concurrent validity of with respect to their directly measured values was on average moderate-to-large. The obtained F-V relationships also revealed that (1) the assessment of maximum F and P could be somewhat more reliable and valid than the assessment of maximum V, (2) natural countermovement jumps should be employed rather than the jumps performed from a fixed squat position, while (3) both maximum and averaged F and V variables could be used despite revealing markedly different regression parameters. Conclusions The data generally reveal a reliable, valid, strong and quasi-linear F-V relationship across variety of vertical jumps and the recorded F and V variables. Therefore, we conclude that the loaded vertical jumps could be developed into a routine method for testing the force, velocity, and power generating capacity of leg extensors.

Evaluation of force–velocity and power–velocity relationship of arm muscles

“…Note that the results have been obtained from either the maximum (Vandewalle et al 1987;Rahmani et al 2001;Hintzy et al 2003) or mean F and V data (Samozino et al 2012(Samozino et al , 2014aRavier et al 2004), or both (Cuk et al 2014;Sprague et al 2007). Nevertheless, note that the standard methodological approach [c.f., (Vandewalle et al 1987;Samozino et al 2012;Cuk et al 2014)] of the cited studies has been based on the manipulation of external loads providing a range of F and V data that allows for applying the linear regression model (see "Methods" for details).…”

“…However, more recent studies have suggested that the F-V relationship of maximum performance multi-joint tasks could be approximately linear, such as when obtained from leg extensions where leg muscles act through closed kinetic chains (Samozino et al 2012(Samozino et al , 2014bYamauchi et al 2009), cycling (Driss and Vandewalle 2013;Nikolaidis 2012;Ravier et al 2004), vertical jumps (Cuk et al 2014;Rahmani et al 2001;Samozino et al 2014a;Sheppard et al 2008;Vandewalle et al 1987), or upper body movements (Nikolaidis 2012;van der Tillar 2004;Hintzy et al 2003;Sprague et al 2007;Cronin et al 2003). Note that the results have been obtained from either the maximum (Vandewalle et al 1987;Rahmani et al 2001;Hintzy et al 2003) or mean F and V data (Samozino et al 2012(Samozino et al , 2014aRavier et al 2004), or both (Cuk et al 2014;Sprague et al 2007). Nevertheless, note that the standard methodological approach [c.f., (Vandewalle et al 1987;Samozino et al 2012;Cuk et al 2014)] of the cited studies has been based on the manipulation of external loads providing a range of F and V data that allows for applying the linear regression model (see "Methods" for details).…”

Volume estimations for combined free-weight and rubber-band resistance exercise

“…While not the primary purpose of this research, the quantification of internal loads such as body mass and the contribution of work on the muscular system are also important in understanding the stresses placed on the musculoskeletal system during training. With consideration to elite lifters and near-maximal attempts, when external loading would be the dominant factor in total work performed, body weight alone can represent a proportionately large source of work for beginners, lower intensity efforts, as well as during loaded jumping exercises (Cuk, et al, 2014). While additional investigations are required to firmly describe and entrench the combined work done to overcome external and internal factors, an approximation can be made for body mass using existing models from Dempster and Gaughran (1955;1967).…”

Mechanical Misconceptions: Have we lost the "mechanics" in "sports biomechanics"?

“…For example, investigators have "simulated an increase or decrease in body weight" by attaching elastic bands to a pulley system to provide assistance to, or resistance against, an individual while performing vertical jumps [61,62]. Because the authors studied a highly dy-namic task, the inertial effects of increased body (massinduced) weight would not have been reflected by the constant external force that was applied, which may affect the interpretation of some results.…”