Intra-rater reliability of rectus abdominis diastasis measurement using dial calipers

Aust J Physiother. 1997;43(2):109-114. doi: 10.1016/s0004-9514(14)60405-0.


To date, physiotherapists have relied upon the use of finger widths for measurement of rectus abdominis diastasis (RAD). This method has been proven unreliable, due to variations in finger widths. The intra-rater reliability of dial calipers for measurement of RAD was investigated by this study, using a repeated measures design. Measurements were taken at rest and during contraction on three occasions in 30 postpartum subjects. High reliability was demonstrated for resting and active RAD measurements, (ICC=0.93 and 0.95 respectively). In conclusion, dial calipers are a reliable measuring device when used by a single clinician. Further testing is required to determine inter-rater reliability.