The point-to-point test: A new diagnostic tool for measuring lumbar tactile acuity? Inter and intra-examiner reliability study of pain-free subjects

• The point-to-point test (PTP) is a new approach aimed at measuring lumbar tactile acuity.
• The reliability of PTP is good and moderate for two investigated points.
• The data suggest that PTP is more reliable than the two-point discrimination test.
• Further research on the validity of the new test is needed.

A two-point discrimination test (TPD) is commonly used to investigate lumbar tactile acuity. However, low inter-examiner reliability and difficulties in execution significantly limit its application. Therefore the aim of this study was to compare the inter- and intra-examiner reliability of a new approach, the point-to-point test (PTP), with the TPD. Twenty-one pain-free subjects attended the inter-examiner stage of the study. Eighteen of them were further recruited into an intra-examiner (reproducibility and repeatability) reliability study. PTP was performed on the three points plotted at the L3 spinal level. Point ‘0’ overlapped with the L3 spinous process, from which points ‘1’ and ‘2’ were horizontally separated by 5 and 10 cm, respectively. Participants manually indicated a point previously touched by the examiner, while the distance (error) was measured. Reliability was determined with the intraclass correlation coefficient (ICC2,3). The results revealed good and moderate inter- and intra-examiner reliability at point ‘1’ (ICC2,3 = 0.68–0.84) and good reliability at point ‘2’ (ICC2,3 = 0.84–0.86). At point ‘0’, reliability was moderate to poor (ICC2,3 = 0.13–0.63). TPD was characterised by a poor to moderate level of inter- (ICC2,1 = 0.51; ICC2,3 = 0.56) and intra-examiner reliability (ICC(2,1) = 0.50; ICC2,3 = 0.74). Our findings suggest that PTP is more reliable than TPD at two investigated points at the L3 spinal level. However, further research on PTP validity data is strongly warranted.