The trunnion is a very important component of the shaker system. It is the U shaped support base that supports the electrodynamic shaker body itself. The shaker trunnion allows the shaker to be rotated in place and provides convenient mounting holes for hanging from a lateral excitation stand, for example the 2050A shaker stand. Without a trunnion, it is very difficult to set up a shaker for modal testing. The trunnion allows the shaker to be configured in different skewed orientations and angles for excitation. Skewing the input force can be particularly important for exciting structures with vertical and lateral modes that are highly uncoupled. The trunnion is also beneficial when aligning the shaker to the structure for modal testing.