Reliability of the Biodex B-2000 Isokinetic Dynamometer and the Evaluation of a Sport-Specific Determination for the Angle of Peak Torque During Knee Extension
Note: [*] Department of Health and Sport Sciences, Room 120, Huston Huffman Center, University of Oklahoma, Norman, OK 73019.
Note: [**] Address reprint requests to Michael G. Bemben, PhD, Department of Health and Sport Sciences, Room 120, Huston Huffman Center, University of Oklahoma, Norman, OK 73019.
Note: [***] Health and Fitness Institute, 2231 Gallaxy Court, Concord, CA 94520.
Abstract: The purpose of this study was to assess the reliability of the Biodex B-2000 Isokinetic Dynamometer and to determine whether there exists a sports-specific angle at which concentric peak torque (PT) is generated during both right and left isokinetic knee extension exercises at 60 deg/sec and 450 deg/sec. Thirty college-aged men (soccer, n = 10; baseball, n = 10; and nonathlete controls, n = 10) were tested on the Biodex B-2000 isokinetic dynamometer. Five members of each group were retested on a 2nd day to determine reliability. Anthropometric measurements included leg lengths, thigh circumferences, and anterior and posterior thigh skinfolds. Reliability measures found no significant differences between days concerning PT or the angle of PT for either leg; however, the reliability coefficients were generally higher for the athletic groups, as well as for the slower isokinetic speed. There were no significant differences between the three groups concerning PT and the angle of PT. Therefore, their data were combined to evaluate right versus left leg measures. Again, no significant differences were observed concerning PT and the angle of PT that both legs generated. In conclusion, generally reliable data can be obtained on the Biodex B-2000 at the slower speeds regardless of athletic ability. There also appeared to be a specific joint angle (17 deg at 60 deg/sec and 55 deg at 450 deg/sec) at which PT is generated independent of athletic ability or leg dominance. Deviations from these angles of PT may indicate injury or a predisposition for injury in the force-producing musculature of the upper leg. These results suggest that normative data could be established that would aid physicians, therapists, and trainers to determine if the angle of PT for a specific testing protocol is appropriate or if further evaluation is needed.
Keywords: Sport-specific and speed-specific angle of peak torque, knee extensors, concentric assessment
