Evaluation of leg muscles’ mechanical capacities using a linear force-velocity relationship

Standardna mišićna relacija sila-brzina (F-V) može se primenjivati u testiranjima mehaničkih osobina mišića. Generalizacija parametara F-V relacije modela dva opterećenja sa jedne mišićne grupe na druge i primena ovog modela u izokinetičkim uslovima nije dovoljno istražena. Ciljevi su realizovani kroz dva dela istraživanja. U prvom su postavljeni ciljevi: Da se utvrdi linearnost F-V relacije, konkurentna validnost parametara modela dva opterećenja i mogućnost generalizacije između istih parametara modela dva opterećenja pri skokovima sa počučnjem, na bicikl ergometru i pri opružanju potkolenice u izometrijskim uslovima. U drugom delu istraživanja cilj je bio da se utvrdi konkurentna validnost parametara modela dve brzine kod opružanja potkolenice u izokinetičkim uslovima. Rezultati prvog dela istraživanja pokazali su da su parametri modela dva opterećenja bili veći od direktno izmerenih varijabli za sve testove. Korelacija između pomenutih parametara je bila visoka, osim pri parametru sile na bicikl ergometru. Rezultati su pokazali da je korelacija između istih parametara novog i standardnog modela pri različitim testovima za mišiće nogu varirala od umerene do visoke. Rezultati drugog dela istraživanja pokazali su da je F-V relacija gotovo linearna. Dobijena je gotovo identična F-V relacija primenom modela dve brzine, pri samo dve standardne ugaone brzine - 60 i 180 °/s. Dobijeni rezultati govore u prilog upotrebi modela dva opterećenja koji je daleko jednostavniji, a daje jednako kvalitetne informacije kao klasičan regresioni model približno linearne F-V relacije. Pokazano je da je mogućnost generalizacije mišićne snage nešto veća, nego generalizacija mišićne sile. Ovaj naučni doprinos otvara mogućnost pojednostavljenja testiranja mehaničkih kapaciteta mišića.he standard muscle force-velocity (F-V) relationship can be applied in testing the mechanical properties of muscles. The generalization of the parameters of the F-V relationship of the two-load model from one muscle group to another and the application of this model under isokinetic conditions have not been sufficiently investigated. The objectives have been achieved by two parts of the study. Aims within first were: To determine the linearity of the F-V relationship, the concurrent validity of the two-load parameters and the possibility of generalization between the same parameters of the two-load model during testing in squat jumps, on the cycle ergometer and for lower leg extension under isometric conditions. In second part of the study, the aim was to determine the concurrent validity of two-velocity model parameters in lower leg extension under isokinetic conditions. The results of the first part of the study showed that in all tests the parameters of the two- load model were higher than the directly measured variables. The correlation between the above parameters was high, except for the force parameter on the cycling ergometer. The results showed that the correlation coefficients between the same parameters of the new and the standard F-V model varied from moderate to high in different tests for the leg muscles. The results of the second part of the study showed that the F-V relationship was approximately linear. An almost identical F-V relationship was obtained by applying the two- velocity model, at only two standard angular velocities - 60 and 180 °/s. The results obtained speak in favor of applying the two-load model, which is far simpler, and provides the same quality of information as the classical regression model of approximately linear F-V relationship. It has been shown that the possibility of generalizing the muscle power is slightly higher than the generalization of the muscle force. This scientific contribution opens the possibility to simplify the testing of mechanical muscle capacities