Reliability problems associated with the modified Schöber technique for true lumbar flexion measurement.

The modified Schöber technique, a method for assessing lumbar spine flexion, was subjected to an analysis of reliability. Fifty normal subjects (21 men, 29 women) were evaluated for lumbar flexion mobility using a blind inter-rater "worst case" protocol. Simultaneously, other sources of error affecting test reliability, such as presence of dimples of Venus, relationship of skin distraction to movement of underlying structures, and upper level of Schöber skin landmarks were also considered. Analysis suggested that systematic error can be introduced that adversely affects inter-rater reliability (r = 0.71). Moreover, skin landmarks are inconsistently present, being completely absent in 26% of cases. Skin tends to distract even over completely immobile bony structures (eg, the sacrum), whereas, on average, only 3.5 of the 6 spinal segments (T12-S1) are included in the Schöber technique for purported measurement of "lumbar spine flexion." The utility of this method is questioned on both scientific and clinical grounds.