M Geelhoed, J McGaugh, P Brewer and D Murphy
The aim of this study was to test out the proposed model of locating transverse processes (TPs) in the thoracic spine through surface palpation. Many clinicians use the more superficial spinous processes (SPs) when orientating themselves to the thoracic spine. The "rule of threes" is often employed to help with this process. Following a pilot study the authors felt that the rule of threes was not an accurate predictor of level. The study looked at 15 cadavers and a more accurate rule of prediction is that TPs are generally at the level of the SP of the adjacent cranial thoracic vertebra (the vertebra above). The authors pointed out that it may be more difficult to predict the levels of T11 and T12 as the position of the TP varies in relation to that of the SP.
Journal of Orthopaedic Sports Physical Therapy (2006); 36(11): 876-881