The effect of handlebar position and vibration on the electromyographic activity of cervical spine extensors during stationary bicycling

The objectives of this study were to obtain normative data on cervical extensor EMG activity during bicycling with and without vibration using three different handlebar types; to compared EMG activity between the different handlebar types and vibration conditions; and, to determine if there was a correlation between neck extension and trunk inclination angles and EMG activity. A 2 x 3 factorial with repeated measures research design was used. Eighteen untrained male bicyclists between the ages of 21 and 48 were tested on a bicycle fixed to an indoor trainer. Cervical extensor EMG activity was measured using upright, racing, and aero style handlebars, with and without vibration of a frequency of approximately 20 Hz applied through the front fork of the bicycle. The normalized IEMG activity of the cervical extensors increased in the order of upright to racing to aero riding positions, both with and without vibrations. Significant differences were found (p\u3c.05) between the upright position and racing and aero positions without vibrations and between the aero position and upright and racing positions, with vibration. Vibration was found to significant (p\u3c.003) increase the normalized IEMG activity of the cervical extensors in all riding positions. A weak, but significant (p\u3c.05) correlation (rs-.266) between trunk inclination angle and normalized IEMG activity of the cervical extensors without vibration was found. Reduction of vibration during bicycling or a change to the upright riding position could be used as preventive measures during bicycling or during the treatment of neck pain in bicyclists