Abstract des Autors

The intertest reliability of an isokinetic (90 deg/s) knee extensor endurance protocol consisting of 100 maximal contractions was investigated. A group of healthy moderately active subjects (n = 16) was tested twice with an interval of 14 days. A Biodex isokinetic dynamometer was used for eccentric and concentric torque measurements. Absolute endurance (mean peak torque of contraction 50 to 100), relative endurance (absolute endurance divided by the mean peak torque of contraction 1 to 5), and total work were analyzed. Intraclass Correlation Coefficients (ICCs) for concentric knee extensor endurance indicated high reliability (0.90-0.96). For eccentric measures, ICCs were high for absolute endurance and total work (0.93 and 0.92) but not for relative endurance (0.71). Systematic increases from test to retest were observed for concentric absolute endurance (5%), eccentric absolute endurance (8%) and eccentric total work (9%). This study has shown that eccentric as well as concentric isokinetic knee extensor endurance can be reliably measured using a protocol consisting of 100 maximal contractions. Estimates of required sample sizes for detecting clinically significant differences between paired observations using this protocol are provided. Verf.-Referat