A Kinematic And Kinetic Analysis Of The Ergometer And Recumbent Cycles At Two Different Seat Positions

Abstract

The bicycle ergometer has been used as a rehabilitative tool for patients with various knee injuries. The recumbent bicycle, a relatively new ergometer, is also being used in this capacity. Mechanical loads on different joint structures can be controlled by changes in the workload, pedaling rate, and seat position of the ergometer. The purpose of this study was to compare kinematic and kinetic variables on the traditional ergometer (ERG) with the new recumbent (REC) cycle at 2 different and seat positions. Twenty females (age: 20+/-1.6 yrs; hgt: 167.1+/-5.3 cm; mass: 61.8+/-9.5 kg) volunteered as subjects. Subjects were given a brief warm-up time and then cycled for 10 seconds at each condition: ergometer-large angle at the knee (ELA), ergometer-small angle (ESA), recumbent-large angle (RLA) and recumbent-small angle (RSM). Each subject was videotaped from the sagittal view with a Panasonic AG-450 camcorder set at 1/500th shutter speed and 30 Hz frame rate. Reflective markers were placed at 5 lower body and trunk landmarks of the right side of each subject. Each subject's view was captured, data points digitized, transformed and spatial coordinates analyzed using the Ariel Performance .Analysis System. Data were smoothed with a digital filter set at 10 Hz. ANOVA with randomized blocks design was utilized to examine differences in the kinematic and kinetic variables. A significant difference was found between RLA and ELA for the variables of: hip (HROM), knee (KROM) and ankle (AROM) range of motion, Y peak force of hip (YHP), Y peak force of knee (YKN) and Y peak force of ankle (YAK). Significant differences were found between RSA and ESA for HROM, KROM, YHP, and YKN. No significant differences were noted in the X peak force of the joints under any condition. Subjects experienced greater ROM at the joints during the ERG conditions but greater peak forces during the REC conditions. Additional research needs to be conducted to determine the effectiveness of the recumbent cycle in the rehabilitation setting.