When inspecting old homes I often come across interesting methods for shoring up or supporting sagging floor joists. In this case the homeowner had used a 2x4x4 piece of wood as a spacer under a 2x4x12, under a couple of 2x4x48's.
The problem is that the 2x2x4 just doesn't have the ability to take the load due to it's small size and has crushed. Without correction this will eventually just split and squirt out the sides.