Does the landmarks used in the modified schober test cover the entire lumbar spine? Proposal for a new procedure

Introduction Although the Modified Schöber Test (McRae and Wright version) has been widely used to measure the flexibility of the lumbar spine, its validity remains controversial
Purpose The aim of this study was to compare the validity of the Modified Schöber Test (MST) to a new test based on different cutaneous marks by investigating (by means of MRI) if the distance between these landmarks cover the complete lumbar spine
Method 80 Patients with low back pain having a lumbosacral MRI prescription were included in the study. Radiopaque markers were placed 10 cm above (superior point) of the lumbosacral junction, identified by palpation, and 5 cm below (inferior point) for the MST (n = 80/80) and, for the New Test (n = 52/80), at a point 5 cm below (inferior point) of the line passing through the posterior superior iliac spines (PSIS-5) as well as at a point (superior point) corresponding to 30% of the distance between this inferior point and C7. The subsequent imaging examination was performed in a supine position
Results For the MST participants, the superior point was on (41,25%), above (8,75%) or below (50%) L1. For the new test, 100% of the skin markers were on (53,85%) or above (46,15%) L1
Conclusion The new test presented in the present study might be more valid than the traditional MST to reflect the coverage of the full lumbar spine and therefore its mobility