Electromechanical delay estimated by using electromyography during cycling at different pedaling frequencies.

The purpose of this study was to propose a new method that can be used to calculate electromechanical delay (EMD) without the measurement of forces. A secondary purpose, as an example of the importance of measuring EMD, was to predict muscle force development events based on the EMG activity of selected muscles during cycling at different pedaling frequencies. EMD was estimated using newly derived equations based on activation dynamics hypothesis. Tibialis anterior (TA) and soleus (SL) muscles of 16 male participants were studied while subjects pedaled at targeted cadences of 60, 80, and 100 revolutions per minute. The estimated EMDs of TA and SL were significantly different from each other with means of 68.1 and 88.7 ms, respectively. The average crank angle for the initiation and time to peak TA contraction was estimated at 75 +/- 35 degrees and 26 +/- 15 degrees before the crank reached top-dead-center (TDC), while the contraction ended at 31 +/- 19 degrees after the TDC on average. The projected starting, peak and end angles of SL contraction activity were 45 +/- 18 degrees , 123 +/- 13 degrees, and 218 +/- 35 degrees after the TDC, respectively. There was no difference among different pedaling cadences observed for these mechanical events. The proposed method was proven to be effective in studying EMD and estimate muscle contraction patterns during cycling.