INFLUENCE OF AN ERGOLINE BICYCLE ERGOMETER ON BODY SEGMENT KINEMATICS AND POSTURE
AbstractINTRODUCTION Bicycle erogmeters have been the most used modality in the investigation of physiological and biomechanical parameters in cycling, for their ease of calibration and adaptation to various body size. In addition, the possibility to apply rackg type saddles, handlebars, and pedals allows the athlete to more closely replicates road racing condition in laboratory. There is, however, very little information about the effects of these devices on body kinematics. By a simultaneous right and left 3-D kinematic analysis, the purpose of this study was to compare body segment kinematics and posture of five experienced cyclists while pedaling on their own racing bicycle and on a widely used bicycle ergometer. METHODS Five experienced road cyclists were the subjects of this study. Each athlete first pedaled on his own bicycle mounted on rollers fitted with a variable-load device and then, performed on an electronically braked cycle erogmeter (Ergoline, Germany) which was mechanically modified to allow the athletes to correctly adjust the seat and handlebar, and to use their nonnal cycling shoes and cleats. Using the ELm system motion analyzer (four 100 Hz-TV cameras), the 3-D coordinates of small retoreflective markers glued onto 19 anatomical repere points were recorded with the subjects pedaling at 90-95 rpm. RESULTS As it can be seen in the table, considering lower limb joint motion in the sagittal plane, sigdcant differences between the two pedaling conditions were found in the ankle range of motion (ROM) and in maximum (MAX) and minimum (MIN) angular hip flexion. Others relevant differences were evident examining joint rotation center trajectories in the frontal plane, with the foot and shank performing farther from the bicycle frame using the Ergoline. In most of the subjects this resulted in an excessive transverse/frontal knee motion. The pelvis is significantly less anteroversed on the bicycle ergometer with more pelvic tilt in the frontal and horizontal plane. CONCLUSION The use of the examined ergometer significantly altered lower limb and pelvis kinematics in the frontal plane compared to standard bicycle. This must be considered when this device is used for training andlor to collect physiological and biomechanical data.
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