Physiotherapists' reliability of inter-recti distance measurement with real-time ultrasound across a mixed women population sample.

Ultrasound imaging has become popular among physiotherapists for monitoring diastasis rectus abdominis postpartum, but its reliability requires further exploration. To investigate physiotherapists' intra-tester, inter-tester, and test-retest reliability of inter-recti distance measurement utilizing real-time ultrasound across a mixed women sample. Reliability study. Volunteers comprising nulliparous and parous women of different ages and body mass index participated. Five physiotherapists performed ultrasound measurements, following sonographic training. Four conditions were tested in supine; rest, curl-up, transversus abdominus activation, and transversus abdominus with curl-up. Three locations were randomly measured: umbilicus, 3 cm above the umbilicus, and halfway between the umbilicus and xiphoid process. For intra-tester reliability, each therapist undertook three repeated measurements. For inter-tester reliability, mean inter-recti distance measurements were explored across any two tester combinations within and across sessions. Test-retest reliability explored repeated measurements 5-8 days later. Data were analyzed with intraclass correlation coefficients2,1. 54 women (33.2 ± 15.2 years old, body mass index: 24.2 ± 3.7), 19 (35.2%) being parous participated. Intra-tester reliability across each physiotherapist was very good (intraclass correlation coefficients = 0.677-0.989). Intra-session reliability across any two testers yielded very good results (intraclass correlation coefficients = 0.76-0.92), whereas across-session yielded good reliability (intraclass correlation coefficients >0.76) except for one condition (3 cm above umbilicus in combined transversus abdominus and curl-up). Test-retest reliability was also very good (intraclass correlation coefficients = 0.78-0.96). Significant differences in inter-recti distance were found, with parous women showing consistently larger values (p < 0.05). Physiotherapists, following sonographic training, can reliably measure inter-recti distances in both nulliparous and parous women across active and resting tasks. Thus, ultrasound measurement of inter-recti distance is recommended in physiotherapy practice for monitoring diastasis rectus abdominis and assessing rehabilitation progress. However, sub-umbilical inter-recti distance measurements and the impact of co-contraction on reliability require further research.