503 KB0 KB200520252022Fonda, BorutKozlovič, PeterŠarabon, Nejcštevilka:1/2letnik:70str. 181-187ISSN:0353-7455COBISSID:113088259URN:URN:NBN:SI:doc-UOOJM8YVslFakulteta za športŠport (Ljubljana)biomehanikakolesarjenjekolesarjikolesarstvošportučinkovitostŠtudija primera| vpliv dolžine gonilke na biomehanske lastnosti kolesarjenja|To date, studies were primary focused on crank length impact on metabolic efficiency and kinematics of cycling with emphasis to joint range of motion, crank angular velocity and crank power. The purpose of this study was to examine the effects of crank arm length on cycling biomechanics at different workloads. Cycling efficiency and joint forces and torques of the lower extremity were monitored as well as potential biomechanical characteristics of cycling to the occurrence of overuse injuries in the lower extremity joints. Two well trained cyclists volunteered for the study. They cycled on an indoor ergometer twice for one minute at 175 and 225 W. Sessions were performed using crank arm length of 160 mm and 172 mm. The net joint forces, joint power, crank torque, resultant and effective force on the pedals, index of effectiveness, pedal forces, patellofemoral force, tibiofemoral force and knee angle were calculated. Results showed that shorter crank reduce loads of internal and external knee torque in transverse plain as well as varus and valgus torque in sagittal plain. Also, hip shear forces and patellofemoral forces were reduced by 10 % using shorter crank. Cycling effectiveness wasn’t affected by crank arm lengthV dosedanjih študijah je bil raziskan vpliv dolžine gonilke na metabolično učinkovitost in kinematiko kolesarjenja, pri čemer so opazovali obseg giba v sklepih, kotno hitrost gonilke in moč na gonilki. V tej študiji primera smo raziskali vpliv dolžine gonilke na biomehaniko kolesarjenja pri različnih obremenitvah. Zanimal nas je vpliv dolžine gonilke na učinkovitost kolesarjenja ter potencialne biomehanske lastnosti kolesarjenja na nastanek poškodb v sklepih spodnjih okončin zaradi prekomerne obrabe. V raziskavi sta sodelovala dobro trenirana kolesarja. Kolesarila sta dvakrat po eno minuto na 175 W in 225 W, z dolžino gonilke 160 mm in 172 mm. Po meritvah smo izračunali neto sklepne sile in moč v gležnju, kolenu in kolku, izračunali smo navor na gonilki, skupno in učinkovito silo na pedalu, indeks učinkovitosti, sile na pedalu, patelofemoralno in tibiofemoralno silo ter kot kolena v iztegu. Rezultati so pokazali, da sta navora v smeri notranje in zunanje rotacije v prečni ravnini in navora v smeri odmika in primika goleni v čelni ravnini manjša pri krajši gonilki, pri čemer se strižna sila v kolku in kompresijska patelofemoralna sila pri daljši gonilki povečata za 10 %. Ne glede na dolžino gonilke se je učinkovitost kolesarjenja spremenila neznatnoTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za šport