METHODS
The electrical activity of both the sternocostal head and the clavicular head of the pectoralis major muscle contraction will be measured via EMG. The action potential in all muscular activity comes in response to motor unit recruitment, and the electrical impulses of such will be measured in voltage. These signals will be picked up by skin-surface electrodes and converted into readable data via EMG.

As tested in this study, both the bench press and cable crossovers were examined over two trials, collecting 10 seconds of data in each, and combining the two sets.

As most exercise programs do not routinely incorporate exercises performed at maximal strength capacity, this study targeted a percent of this maximum between the 20% and 81% that has shown up in numerous other tests. This was done in the bench press particularly in attempt to ensure standardization of a commonly used bar path as well as the possibility of an influence on pectoralis involvement as it relates to grip width.

Because horizontal bench press is thought to most efficiently target the sternocostal head of the pectoralis major (Barnett, et. al., 1995), that is the primary area of focus. However, the clavicular head will be measured as well in order to develop a greater range of data for comparison between exercises.

Once data was collected, the EMG was rectified, filtered (low pass Butterworth @ 10 Hz, roll off 5 Hz), integrated, and averaged over the multiple trials, and compared via repeated measures ANOVA.