Incorrect bicycle saddle height may lead to discomfort and knee injuries especially for casual or normal cyclist. Each day, around the world, the numbers of cyclists are increasing. This necessitates an appropriate saddle height configuration method to enhance cyclist performance. This research not only investigate the muscle fatigue but also taking into concern of knee joint angle at two different saddle height (Heel to Pedal and LeMond), during cycling. Seven male active right dominant subjects voluntarily participated in this study. Five lower limb muscle are investigated (Rectus Femoris, Vastus Lateralis, Vastus Medialis, Gastrocnemius Lateralis, and Gastrocnemius Medialis) using Surface Electromyography. Prior to cycling test, the subjects at first warm up for five minutes at (60-RPM cadence, 50-Watt load power), then rest for five minutes to measure Heart Rate and to make sure that sEMG cables connected securely. The cyclists cycled until fatigue and try to maintain constant power of 100 watt and 60 RPM cadence. High-speed video have been recorded for later analysis on knee joint angle measurement. The sEMG signals were transformed to time-frequency domain using Short Time Fourier Transform. The feature extraction methods used in this research were instantaneous median frequency (IMDF) and instantaneous mean frequency (IMNF). These features were extracted from the sEMG signals to detect the muscle fatigue and statistical analysis were applied to the extracted features to specify if there is significance difference in muscle fatigue between each saddle height. ANOVA results for individual muscle between Heel to Pedal and LeMond shows variation between results. Vastus Lateralis and Vastus Medialis show significance in fatigue with p-value <0.05 in both (IMNF and IMDF percentage of deviation), the other muscles have different results and p-values. Knee Angle results shows that heel to pedal knee angle mean (43.15°) is higher than LeMond angle results (34.82°). Higher knee angle increase the risk of knee injuries. The knee angle was higher for all subjects during Heel to Pedal cycling session compared to LeMond session. However, ANOVA test results shows that there is no significance in knee angle that due to the higher standard deviation for both results where p-value result was 0.072 >0.05. The overall outcome of this research have successfully demonstrate that LeMond method is superior to H/P method in term of fatigue and risk of knee injury.
