title: Reliability of the inter-rectus distance measured by palpation. Comparison of palpation and ultrasound measurements.
abstract: An increased inter-rectus distance (IRD) is a common condition in late pregnancy and in the postnatal period. The condition is difficult to assess. Palpation is the most commonly used method to assess IRD. To date there is scant knowledge of intra and inter-tester reliability of palpation to measure IRD and how palpation compares with ultrasound measurements. The aims of this study were: 1) evaluate intra and inter-rater reliability of abdominal palpation; 2) validate abdominal palpation of IRD measurements using ultrasound imaging as a reference. Two physiotherapists (PTs) conducted the palpation study in random order, blinded to each other's assessments. IRD was measured as finger widths between the two rectus abdominis (RA) muscles. Ultrasound images were recorded at the same locations as the palpation test. A blinded investigator measured the IRD offline. Palpation showed good intra-rater reliability between days expressed by a weighted Kappa (wK) higher than 0.7 for both physiotherapists, and moderate inter-rater reliability (wK = 0.534). Ultrasound was found to be more responsive for differences in IRD compared with values obtained by palpation. The intra-rater reliability was higher than the inter-rater reliability. Besides the difference in experience with palpation testing between the PTs, this result may be due to differences in finger width and/or the subjective interpretation of abdominal soft-tissues pressure. Ultrasound measures are highly sensitive to changes of IRD, which is not possible to replicate by palpation assessment using a finger width scale. Palpation has sufficient reliability to be used in clinical practice. However, ultrasound is a more accurate and valid method and is recommended in future research of IRD.
authors.affiliation: Faculty of Human Kinetics, Technical University of Lisbon, CIPER, LBMF - Neuromechanics Research Group, Portugal. patimota@gmail.com
authors.forename: Patrícia
authors.initials: P
authors.lastname: Mota
authors.forename: Augusto Gil
authors.initials: AG
authors.lastname: Pascoal
authors.forename: Fátima
authors.initials: F
authors.lastname: Sancho
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Carita
authors.forename: Kari
authors.initials: K
authors.lastname: Bø
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D015588:Observer Variation; D010173:Palpation / Q000379:methods*; D017568:Rectus Abdominis / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D016683:Supine Position; D018608:Ultrasonography, Doppler / Q000379:methods*; D014894:Weights and Measures; D055815:Young Adult