ANALYSIS OF CARDIOSKELETAL SYNCHRONIZATION DURING LOCOMOTION.

The application of two analytical techniques, spectral analysis and three-dimensional plotting, used to investigate the relationship between cardiac and skeletal muscle firing patterns during normal human locomotion is described. An accelerometer was attached to the sternum to produce a signal representating each step and single-lead electrocardiography (ECG) for the cardiac timing. Both signals were recorded on FM tape while the subjects walked and ran on a motorized treadmill, and later, by sampling them from the FM tape at 120 Hz, their power- and cross-spectra were obtained. The two signals were also recorded on a computer at each treadmill speed. Using the accelerometer signal peaks to identify the start and end of a step cycle, the ECG signals were plotted three-dimensionally against time for qualitative analysis. The combination of these two approaches has provided insight into cardioskeletal synchronization.