Methodological Differences in the Interpretation of Fatigue Data from Repeated Maximal Effort Knee Extensions

Method: In this study, we quantified fatigue from a repeated maximal effort isokinetic knee extension test using different methods, as seen in published research. Nine healthy males and nine healthy females performed 50 concentric knee extensions at 180°•s. For each repetition, torque was quantified as either peak torque (PT), torque at the mid-point of the range of motion, and torque integrated over the full, middle 30° range of motion, and isokinetic range of motion. Fatigue Index was quantified using either the first and last three or five repetitions or the peak and last three or five repetitions. Torque slopes were quantified using all repetitions or repetitions that occurred at and beyond the repetition at which the greatest torque value occurred.