A Study on Lower Limb Joint Angles and Muscle Activities during Maximal and Sub-maximal Pedaling by Saddle Heights

Cyclists can achieve an effective pedaling through the fitting to adjust various frame sizes by considering their physical characteristics. Among several fitting parameters, saddle height is a key factor for both injury prevention and optimal cycling performance. The purpose of this study was to analyze lower limb joint angles and muscle activities due to different saddle heights via well-known knee angle method during maximal & sub-maximal pedaling. Seven elite cyclists (Age : 34.3±3.5, Height : 174.2±4.6, Weight : 82.5±7.2) participated in 10 sec maximal (sprint) test and 3 min submaximal (90RPM) test with 3 different saddle heights which was set to the corresponding height by 25, 30, 35 angle between lower leg and extended shank at bottom dead center position. Movement of hip, knee, and ankle joint was obtained through 3D motion analysis system (Motion analysis Corps., USA), and EMG (Delsys Inc, USA) of biceps femoris (BF) and vastus lateralis (VL) were measured at the same time. Results showed that hip (knee angle: 35, 30) and knee (knee angle: 30, 25) joint angle were significantly increased during maximal test. There was not significantly decreased compared to 25 knee angle during maximal test, and that of biceps femoris at 35 knee angle was significantly decreased compared to 25 knee angle during the sub-maximal test. It is suggested that selection of saddle height for effective pedaling be considered with the cadence and the sport entries of cycling.