Physiological and dynamic response to vibration in cycling: A feasibility study

Comfort in cycling is related to the level of vibration of the bicycle: more vibration results in less comfort and also it can generate health problems for the rider. The vibration level found in the joints of the lower limb while cycling is directly related to the characteristics of vibration exposure and influenced by the movement in this extremity. The aim of this work was the development of a protocol to analyze the dynamic and physiological response of the human body subjected to vibration exposure while cycling. In this preliminary study, the dynamic response is analyzed using the measure of the transmissibility from the pedal to three joints of the lower body (ankle, knee and hip). In addition, the analysis of the physiological response is done through the measure of muscular activity (electromyography). The subject performs a cycling exercise at a constant speed and power (80 RPM, 150 W) with a vibration exposure at six different frequencies (20-30-40-50-60-70 Hz) and with two amplitudes of vibration (2 mm and 4 mm). The accelerometric results are analyzed taking into account the different phases of the pedaling cycle. The preliminary results of our analysis show that the vibration frequency and the different phases of the movement have an influence on the induced vibrations. The frequencies and phases where the transmissibility is higher for each joint are found, as well as the frequencies where the muscular activity is increased