Spine alignment problems can be caused by two different shaft properties. The first which can be found in any material that shafts are made from is shaft bow or straightness. The second which is predominate in the plastic reinforced shafts such as graphite is a hard side along the shaft caused in most cases by the overlap of material along one side of the shaft when it is produced. If we analyze what the affect these two shaft defects have on the performance of the golf club we can see that the primary fault comes in the stability of the shaft as it is loaded. When we test a shaft for a spine we find that the shaft will always seek a stable position when the shaft is loaded/bent away from the hard side or with the built-in bow of the shaft. This then means that the hard side of the shaft should be at the target or the built-in bow should be in the direction of the take-away. This insures the shaft will load or flex on a straight back path and return on the same path for the first 1/4 cycle of the shafts natural frequency to ball impact and being stable during this loading and unloading period. What happens after The first 1/4 cycle period has no affect on the results of the shot. If the shaft is not spine aligned in the club the club head will tend to track inside or outside of the straight or stable loading path and there fore will return to impact on some inconsistent path.