title: [Sincerity of effort: isokinetic evaluation of knee extension].
abstract: The aim of this study was to find a reliable method to evaluate the sincerity of the muscular maximal effort performed in a dynamometric isokinetic test of knee flexion-extension. The coefficient of variation of the peak torque (CV) and 3 new indices were analysed: (1) the average coefficient of variation calculated on the complete peak torque curve (CVM); (2) the slope of the regression line in an endurance test (PRR); (3) the correlation coefficient of the peak torques in the same endurance test (CCR). Twenty healthy subjects underwent assessment in two different trials, maximal (MX) and 50% submaximal (SMX), with 20 minutes of rest between trials. Each trial consisted of 4 tests, each of 3 repetitions, at angular speed of 30, 180, 30, and 180 degrees/s, respectively, and 1 test of 15 repetitions at 240 degrees/s. Our findings confirmed the ability of CV to detect a high percentage of sincere efforts: at 30 degrees/s Sensibility (Sns)=100% and Specificity (Spc)=70%; at 180 degrees/s Sns=75%, Spc=95%. The 3 new indices here proposed showed high characteristics of Sns and Spc, generally better than those of CV. CVM showed at 180 degrees/s Sns=90% and Spc=100%, while at 30 degrees/s Sns=90%, Spc=75%. PRR was the best index identifying all the efforts, except one (Sns=100%, Spc=95%). The CCR coefficient showed Sns and Spc values both of 90%.
authors.affiliation: Fondazione Salvatore Maugeri, IRCCS, Servizio di Bioingegneria e Servizio di Fisiatria Occupazionale ed Ergonomia, Veruno (NO), Italy. roberto.colombo@fsm.it
authors.forename: R
authors.initials: R
authors.lastname: Colombo
authors.forename: G
authors.initials: G
authors.lastname: Demaiti
authors.forename: F
authors.initials: F
authors.lastname: Sartorio
authors.forename: D
authors.initials: D
authors.lastname: Orlandini
authors.forename: S
authors.initials: S
authors.lastname: Vercelli
authors.forename: G
authors.initials: G
authors.lastname: Ferriero