Palpation identification of spinous processes in the lumbar spine

The purpose of this study was to determine the accuracy of manipulative physiotherapists in palpating radiologically identified lumbar spinous processes (SPs).Five experienced manipulative physiotherapists were each allocated a cohort of 15 consecutive low back pain (LBP) patients presenting for X-rays and were asked to use surface palpation to identify the L1, L3 and L5 SPs. Spherical radio-opaque markers were taped to the skin over these palpated points and standard lateral radiographs taken. Measurements were made to determine the proximity of these nominated markers to identified SPs.Seventy-two percent of markers were either placed accurately over the nominated SP or consistently within one SP of the nominated level. Forty-seven percent were accurately placed over the nominated SPs. A greater SP height at L3 and L5, and decreased soft tissue thickness over L5, were associated with an increase in palpation accuracy levels, yet the patient variables of age, sex and body mass index (BMI) had no effect. The strongest effect on accuracy was between-therapist variability.The manipulative physiotherapists used in this study appear to be moderately successful in either palpating a nominated SP or being no more than one spinal level in error. Further research will focus on the choice of palpation procedure and a larger sample.