Inter-Rectus Distance Measurement Using Ultrasound Imaging: Does the Rater Matter?

Reliability of inter-recti distance measurement on ultrasound images captured by novice examiners

BACKGROUND

With the increased interest in inter-recti distance measurement using ultrasound imaging in physiotherapy, there is a question of measurement reliability, and the importance of the examiner's experience.

PURPOSE

The study aimed to investigate the reliability of inter-recti distance measurement in a DICOM viewer software by an experienced radiologist. For the measurement, the radiologist used linea alba images captured by two physiotherapists who were novice examiners.

METHODS

Ultrasound images were acquired by two novice examiners on repeated occasions 7 days apart (sessions A and B) in 28 nulliparous women at supraumbilical, umbilical, and infraumbilical locations along linea alba.

RESULTS

Excellent intra-examiner reliability of inter-recti distance measurements was shown at the supraumbilical and umbilical levels (ICC2,k = 0.941-0.983) with minimal detectable change (MDC95) ranging from 1.31 mm to 2.29 mm. Infraumbilical measurements had good to excellent reliability (ICC2,k = 0.894-0.972) with MDC95 ranging from 0.33 mm to 0.72 mm. Session A inter-examiner reliability was excellent for the mean measurements of two, three, four, and five images taken at each location (ICC2,k = 0.913-0.954) with MDC95 ranging from 0.47 mm to 2.96 mm. Session B inter-examiner reliability was excellent for the mean measurements of two, three, four, and five images taken at the supraumbilical and umbilical (ICC2,k = 0.94-0.98), MDC95 ranging from 1.38 mm to 2.58 mm and good (ICC2,k ≥ 0.81) with MDC95 ranging from 0.72 mm to 0.80 mm at the infraumbilical locations.

CONCLUSION

Novice examiners were able to capture good-quality ultrasound images of the linea alba that allowed for good to excellent intra- and inter-examiner reliability.

Effects of Pilates on inter-recti distance, thickness of rectus abdominis, waist circumference and abdominal muscle endurance in primiparous women

BACKGROUND

Pilates is expected to have a positive effect on women with weakened abdominal muscles after childbirth. Pilates may have a beneficial effect on the structure and function of the abdominal muscles in pregnant women. Therefore, the objective of this study was to investigate the effects of Pilates on inter-recti distance, thickness of the rectus abdominis, waist circumference, and abdominal muscle endurance in primiparous women.

METHODS

Thirty-five primiparous postpartum women were assigned to either the Pilates exercise group (n = 20) or the control group (n = 15). Pilates was undertaken by the exercise group for 50 min/day, 5 days/week, for 4 weeks. The control group maintained their daily activities without any intervention. The inter-recti distance was measured at three locations along the linea alba, and the thickness of the rectus abdominis was measured using ultrasound. Abdominal muscle endurance was measured using a repeated 1-min curl-up test. Waist circumference was also measured.

RESULTS

The exercise group showed significant improvements from baseline in inter-recti distance, waist circumference, and abdominal muscle endurance (p < 0.05). The control group showed no significant improvement in these variables. Compared with the control group, the exercise group showed significantly improved performance in terms of inter-recti distance, waist circumference, and abdominal muscle endurance (p < 0.05).

CONCLUSIONS

The results of this study demonstrate that Pilates was effective in reducing inter-recti distance and waist circumference and improving abdominal muscle endurance in primiparous postpartum women. Pilates is considered an effective exercise for improving muscle structure and function in primiparous postpartum women, helping in the recovery from, and preventing, diastasis rectus abdominis.

Technical aspects of inter-recti distance measurement with ultrasonographic imaging for physiotherapy purposes: the scoping review

BACKGROUND

Inter-recti distance (IRD) measurement using musculoskeletal USI has been used in physiotherapy research, in particular, to investigate pregnancy-related diastasis recti abdominis (DRA) and to seek its effective treatment methods. Severe and untreated diastasis may result in the formation of umbilical or epigastric hernias.

OBJECTIVE

This study aimed to systematically map physiotherapy-related research articles that included descriptions of IRD measurement procedures using USI to present their similarities and differences, and formulate recommendations on the procedure.

DESIGN

A scoping review was conducted according to PRISMA-ScR guidelines, including 49 of 511 publications from three major databases. Publications were selected and screened by two independent reviewers whose decisions were consulted with a third reviewer. The main synthesized data items were: the examinees' body position, breathing phase, measurement sites, and DRA screening methods. The final conclusions and recommendations were the result of a consensus between seven reviewers from four research centers.

RESULTS

Studies used 1-5 measurement sites that were differently determined. IRD was measured at the umbilicus (n = 3), at its superior (n = 16) and/or inferior border (n = 9), and at different levels: between 2 and 12 cm above the umbilicus, or a third of the distance and halfway between the umbilicus and xiphoid (n = 37); between 2 and 4.5 cm below the umbilicus or halfway between the umbilicus and pubis (n = 27). Different approaches were used to screen subjects for DRA.

CONCLUSIONS

The discrepancies between the measurement procedures prevent between-study comparisons. The DRA screening method should be standardized. IRD measurement protocol standardization has been proposed.

CRITICAL RELEVANCE STATEMENT

This scoping review indicates that the inter-recti distance measurement procedures using ultrasound imaging differ between studies, preventing between-study comparisons. Based on the results synthesis, the measurement protocol standardization has been proposed.

KEY POINTS

The inter-recti distance measurement procedures using USI differ between studies. Proposed standardization concerns body position, breathing phase, measurements number per location. Determination of measurement locations considering individual linea alba length is suggested. Recommended locations: umbilical top, ½ of umbilical top-xiphoid, ¼ of umbilical top-xiphoid/pubis distances. Diastasis recti abdominis diagnostic criteria are needed for proposed measurement locations.

Immediate Effect of Kinesio Taping on Lumbopelvic Stability in Postpartum Women With Diastasis Recti: A Review

Diastasis of abdominal muscles is defined as a gap of more than two finger breadths between two rectal abdominal muscle bellies, above or below the umbilicus. According to the literature, female diastasis recti is more common in women who have recently given birth although it also occurs in the male population. Lower back pain is the most prevalent reason for postpartum women to restrict their everyday activities. Women's mobility, discomfort, and typical activities are all concerns for postpartum women, all of which change a person's quality of life. During pregnancy, diastasis of the rectus abdominal muscles is very common to occur. It is linked to instability of lumbar pelvic region and pelvic floor improper function. Recently, the use of Kinesio taping is gaining popularity as a technique to reduce the separation and increase stability. The review of studies revealed that Kinesio taping is highly effective for diastasis recti and in improving the stability of lumbo-pelvic spine which was evaluated by an active straight leg raise test. There are just a few studies accessible that show the need for further research.

The Impact of Hypopressive Abdominal Exercise on Linea Alba Morphology in Women Who Are Postpartum: A Short-Term Cross-Sectional Study

OBJECTIVE

The purpose of this study was to determine the acute effect of an abdominal hypopressive exercise (AHE) on linea alba morphology among women who are primiparous and to compare this effect with that of other common abdominal exercise modalities.

METHODS

A cross-sectional study of 46 women 3 months after first delivery was conducted. B-mode ultrasound imaging of the interrectus distance (IRD) and linea alba distortion was performed 2 cm below (I-point) and above (S-point) the umbilicus and at the mid-point between the umbilicus and xiphoid process (X-point). Images were recorded at rest and during an AHE performed in a supine position, a semi curl-up (SCU), an abdominal drawing-in maneuver (ADIM), and a SCU performed after an initial ADIM (ADIM+SCU).

RESULTS

The SCU exercise narrowed the IRD at the X- and S-points. Compared with SCU, AHE and ADIM widened the IRD at the S- and X-points. No significant differences were found when comparing the IRD at rest, during AHE and during ADIM, but AHE tended to narrow I-point IRD more than ADIM but to widen S-point IRD more than ADIM+SCU. No participant showed linea alba distortion during the AHE or ADIM. When compared, SCU increased the occurrence of distortion with respect to AHE and ADIM. The isolated hypopressive posture did not change the IRD or linea alba distortion.

CONCLUSION

Among women who were postpartum, AHE seemed to narrow IRD below the umbilicus compared with ADIM without either of these 2 modalities generating linea alba distortion, as SCU or ADIM+SCU does. Thus, although no significant differences were found when comparing the IRD at rest and during AHE, the AHE could improve the tensile response of the linea alba without increasing the IRD.

IMPACT

This is believed to be the first study to describe linea alba changes during AHE in women who are postpartum. AHE and ADIM seem to show different effects on infraumbilical IRD. The lack of distortion suggests that linea alba may undergo tensile loading at all levels.

Effectiveness of Yoga on the Interrectus Distance in Early Postpartum Women: A High-Frequency Ultrasound Study

To investigate the effects of ultrasonic evaluation of a progressive yoga exercise program on reducing the inter-recti distance (IRD) among women in the early postpartum period. Postpartum women (n = 116), free of obstetric complications and in recovery following vaginal delivery between weeks 1 and 12, were recruited. Participants were randomly assigned to the control and yoga exercise group in the pre- and post-intervention design. The control group received no treatment, while the yoga exercise group participated in a guided 12-week progressive yoga exercise program started at postpartum week 1. The IRD was examined using high-frequency ultrasound at postpartum weeks 6 and 12. The results showed that the supraumbilical, umbilical, and subumbilical IRD were significantly decreased in the yoga exercise group after the 12-week progressive yoga exercise intervention compared with the first (week 6) and second (week 12) measurements. The differences in IRD at supraumbilical, umbilical, and subumbilical intervals between weeks 6 and 12 significantly increased in the yoga exercise group. Progressive yoga exercises are effective program that reduce IRD among women in the early postpartum period through ultrasound evaluation. In conclusion, women should advocate combined yoga exercise in the early postpartum days following a supervised program.

Association Among Pelvic Girdle Pain, Diastasis Recti Abdominis, Pubic Symphysis Width, and Pain Catastrophizing: A Matched Case-Control Study

OBJECTIVE

Pregnancy-related pelvic girdle pain (PGP) may persist or occur postpartum and negatively affects women's lives. There is uncertainty regarding the association between the structures of the bony pelvis, diastasis recti abdominis (DRA), pain processing, and PGP and to what extent these factors should be considered during physical therapy. This study aimed to evaluate the differences between women with and without PGP shortly after delivery regarding the separation of a pubic symphysis, DRA, and pain catastrophizing.

METHODS

Women diagnosed with PGP 24 to 72 hours after vaginal delivery were matched to pain-free controls according to age and parity. Ultrasound evaluations of diastasis recti (interrecti distance [IRD]) during rest and curl-up task and pubic symphysis (interpubic width) were performed. The Pain Catastrophizing Scale was used to assess the level of catastrophizing. A special Cox regression model was used to fit a conditional logistic regression for a 1:2 matched case-control study.

RESULTS

Thirty-five women with clinically diagnosed PGP and 70 matched controls were included in the study. The PGP group had a significantly higher pre-pregnancy body mass index than the control group. After adjusting for body mass index in multiple conditional logistic regression, the interpubic distance (odds ratio = 1.64; 95% CI = 1.22 to 2.20) and IRD during curl-up (odds ratio = 2.01; 95% CI = 1.08 to 3.74) were significantly associated with PGP. Pain catastrophizing and IRD at rest were not associated with PGP in univariable or multivariable analysis.

CONCLUSIONS

Pain catastrophizing is similar for women with and without PGP early postpartum. However, the degree of the pubic symphysis and rectus abdominis separation during the curl-up task are positively associated with PGP shortly after delivery.

IMPACT

This study indicates that a reconsideration of the way we look at DRA is warranted. The development of a more comprehensive assessment including objective measurements and a biopsychosocial understanding is needed to inform directions for further postpartum physical therapy.

The prevalence and consequences of abdominal rectus muscle diastasis among Finnish women: an epidemiological cohort study

PURPOSE

Post-pregnancy abdominal rectus diastasis (ARD) has raised attention in the field of surgery in recent years, but there is no consensus about when to consider surgery. Our aim was to find out what is the normal inter-rectus distance in fertile aged, female population in Finland and to examine whether there is a linea alba width that would predispose to diastasis-related problems after pregnancy.

METHODS

For this prospective cohort study, women participating early pregnancy ultrasound in Helsinki University Hospital Department of Obstetrics and Gynecology during 1.1.2018-8.3.2019, were recruited. The width of linea alba was measured by ultrasound during the early pregnancy ultrasound. Symptoms were measured by questionnaire including Health-Related Quality of Life (RAND-36) and Oswestry Disability Index for back symptoms and disability.

RESULTS

Linea alba width was measured in total of 933 women. The average inter-rectus distance (IRD) among nulliparous women was 1.81 ± 0.72 cm. After one previous pregnancy, the average linea alba width was 2.36 cm ± 0.83 cm and after more pregnancies 2.55 ± 1.09 cm. There was a positive correlation between previous pregnancies and the increased linea alba width (p = 0.00004). We did not perceive any threshold value of linea alba width that would predispose to back pain or movement control problems in this cohort, in which severe diastasis (over 5 cm) was rare.

CONCLUSION

Mean inter-rectus distance in parous population exceeds stated normative values. Moderate ARD (3.0-5.0 cm) alone does not seem to explain low back pain or functional disability in population level. Severe post-pregnancy diastasis (over 5.0 cm) is rare.

Ultrasonic Characteristics of Diastasis Recti Abdominis in Early Postpartum

Objective

Explore the ultrasound characteristics of early postpartum Diastasis Recti Abdominis (DRA) and provide effective data support for its clinical diagnosis and treatment.

Method

A total of 458 parturients who were diagnosed with DRA in the Chongqing Maternal and Child Health Hospital from December 2017 to September 2020 underwent postpartum ultrasound examinations. All of which were located at four points: 6 cm above the umbilicus (point 1), 3 cm above the umbilicus (point 2), umbilicus (point 3), and 3 cm below the umbilicus (point 4) to detect the interrectus distance (IRD) in the resting and sit-up state of the parturients postpartum and to study the differences in maternal age, weight, and ultrasound diagnosis of IRD at different stages after delivery.

Results

The IRD values of the four measurement points in the resting state of the parturient were significantly greater than the IRD values in the sit-up state. And in the resting state, the IRD value (4.31 ± 1.07 cm) of the point 3 region was the largest, and there were significant differences at different stages of the postpartum women. At the same time, the IRD values of points 3 and 4 have significant differences in parturient of different ages. In addition, the IRD values of the four measurement points of overweight women were higher than those of nonoverweight women.

Conclusion

The umbilicus is the best ultrasound evaluation point for early postpartum DRA. The IRD value at this point in the resting state can be used as reference data for evaluating early postpartum DRA, which provides a useful reference for rapid postpartum recovery of parturients.

Effect of a specific exercise programme during pregnancy on diastasis recti abdominis: study protocol for a randomised controlled trial

INTRODUCTION

Diastasis recti abdominis (DRA) is a common condition in pregnant and postpartum women.Evidence for the treatment of DRA is both sparse and weak. As thiscondition occurs during the last two trimesters of pregnancy and there is a paucity of high-quality studies on a pregnant population, we will conduct a randomised trial on the effect ofa specific exercise programme during pregnancy on DRA.

METHODS AND ANALYSIS

This is an exploratory, assessor-blinded, randomised parallel group trial carried out in aprimary healthcare setting in a Norwegian city. 100 pregnant women, both primigravida andmultigravida, in gestation week 24 presenting with DRA of ≥28 mm willbe included. Participants will be allocated to either an intervention group or a control groupby block randomisation. The intervention group will participate in a 12-week specific exerciseprogramme. The control group will not participate in any exercise intervention. Data collectionwill take place prior to intervention, postintervention at gestation week 37, and 6 weeks, 6and 12 months postpartum. The primary outcome measure will be change in the inter-rectidistance, measured by two-dimensional ultrasonography. Data will be analysed and presentedin accordance with international Consolidated Standards of Reporting Trials guidelines and analysed according to the intention-to-treat principle.

ETHICS AND DISSEMINATION

Ethical approval has been obtained by the regional ethical committee (76296), and allprocedures will be performed in adherence to the Helsinki declaration. The study has beenregistered with ClinicalTrials.gov. Results from this study will be presented atscientific conferences and in peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

NCT04960800; Pre-results.

Establishing measurement properties in the assessment of inter-recti distance of the abdominal muscles in a postnatal women

BACKGROUND

Diastasis of the rectus abdominis muscle is often evaluated in clinical practice but it is unknown which clinical method has the best measurement properties.

OBJECTIVE

The aim of this study was to determine: (i) the criterion validity of the callipers, tape measure and finger-width to evaluate the inter-recti distance of the abdominal muscles compared to ultrasound; and (ii) inter-rater and retest reliability of these methods.

DESIGN

Measurement study.

METHODS

Two physiotherapists assessed the inter-recti distance of rectus abdominis on 50 women postnatally using the three clinical methods. These measurements were compared to ultrasound and assessed for inter-rater and retest reliability.

RESULTS

Callipers had very good positive correlations with ultrasound (r = 0.85 to 0.99) and narrow limits of agreement (LOA) (<6 mm). Finger-width and tape measure had moderate to very good correlation with ultrasound (tape measure r = 0.82 to 0.98; finger-width r = 0.75 to 0.98) with wider limits of agreement (tape measure LOA <8 mm; finger-width LOA <18 mm). Callipers demonstrated excellent inter-rater (ICC = 0.80 to 0.99) and retest (ICC = 1.00) reliability. Inter-rater reliability testing was very good for tape measure (ICC = 0.80 to 0.97) and moderate to very good (ICC = 0.44 to 0.85) for finger-width. Retest reliability demonstrated very good reliability (ICC = 0.99 to 1.00) for both finger-width and tape measure. The largest inter-recti distances, strongest correlations and reliability were found at the level of the lower umbilicus.

CONCLUSION

Callipers, tape measure and finger-width are valid and reliable methods of measuring inter-recti distance in postnatal women. Validity, and relative and absolute reliability were found to be the strongest using the callipers.

Ultrasound Imaging of the Abdominal Wall and Trunk Muscles in Patients with Achilles Tendinopathy versus Healthy Participants

Purpose: To compare and quantify with ultrasound imaging (USI) the inter-recti distance (IRD), rectus abdominis (RA), external oblique (EO), internal oblique (IO), transversus abdominis (TrAb), and multifidus thickness and the RA and multifidus cross-sectional area (CSA) between individuals with and without chronic mid-portion Achilles tendinopathy (AT). Methods: A cross-sectional study. A sample of 143 patients were recruited and divided into two groups: A group comprised of chronic mid-portion AT (n = 71) and B group composed of healthy subjects (n = 72). The IRD, RA, EO, IO, TrAb, and multifidus thickness, as well as RA and multifidus CSA, were measured by USI. Results: USI measurements for the EO (p = 0.001), IO (p = 0.001), TrAb (p = 0.041) and RA (p = 0.001) thickness were decreased as well as IRD (p = 0.001) and multifidus thickness (p = 0.001) and CSA (p = 0.001) were increased for the tendinopathy group with respect the healthy group. Linear regression prediction models (R² = 0.260 − 0.494; p < 0.05) for the IRD, RA, EO, and IO thickness (R² = 0.494), as well as multifidus CSA and thickness were determined by weight, height, BMI and AT presence. Conclusions: EO, IO, TrAb, and RA thickness was reduced and IRD, multifidus thickness and CSA were increased in patients with AT.

Diastasis of rectus abdominis muscles: patterns of anatomical variation as demonstrated by ultrasound

Purpose

The aim of our study was to categorise the anatomical variations of rectus abdominis muscle diastasis (diastasis recti) by using ultrasound (US).

Material and methods

In a one-year period 92 women were evaluated with US because of suspected diastasis of rectus muscles. Patients were examined in a supine position, with head extended, upper limbs aligned to the trunk, and knees flexed. US was performed with high-frequency, broad-band transducers. Trapezoid field-of-view and extended field-of-view were employed to measure diastasis exceeding 5 cm. Diastasis was defined as a margin-to-margin distance > 20 mm at rest and classified according to the following anatomical patterns: open only above the navel, open only below the navel, open at the navel level, open completely but wider above the navel, and open completely but wider below the navel.

Results

Diastasis was found in 82 patients (30-61 years old, mean age 35 years). The width was 21-97 mm, mean 39 mm. The prevalence and severity of the anatomical patterns was as follows: open only above the navel in 48 patients (21-88 mm, mean 40 mm), open only below the navel in one patient (33 mm), open at the navel level in seven patients (23-39 mm, mean 34 mm), open completely but wider above the navel in 24 patients (21-97 mm, mean 41 mm), open completely but wider below the navel in two patients (21-29 mm, mean 25 mm).

Conclusions

The above-navel patterns of recti muscle diastasis are the most common. Even when open completely, diastasis is usually wider above the navel. Knowledge of the anatomical type of rectus muscle diastasis could be of value to the patient (exercises to do and to avoid) and to the surgeon (abdominoplasty planning).

Differences in Linea Alba Stiffness and Linea Alba Distortion Between Women With and Without Diastasis Recti Abdominis: The Impact of Measurement Site and Task

BACKGROUND

The biomechanical implications of diastasis recti abdominis (DRA) are unknown.

OBJECTIVES

To (1) investigate the impact of DRA, measurement site, and task on inter-rectus distance (IRD), linea alba (LA) stiffness, and LA distortion measured at rest and during head-lift and semi-curl-up tasks; and (2) describe the relationships among IRD, LA stiffness, and LA distortion.

METHODS

In this cross-sectional, observational cohort study, brightness-mode ultrasound imaging and shearwave elastography were used on a sample of 20 women. Inter-rectus distance, LA stiffness, and LA distortion were measured at 3 locations, while at rest and during head-lift and semi-curl-up maneuvers. All outcomes were compared between groups (DRA versus no DRA), sites, and tasks. Linear regression models were used to evaluate the relationships among IRD, mean and peak LA stiffness, and LA distortion.

RESULTS

Eleven women with and 9 without DRA participated. Women with DRA demonstrated lower peak and mean LA stiffness and higher LA distortion compared to women without DRA. In women with DRA, IRD and LA distortion were not influenced by measurement site; IRD decreased, LA distortion increased, and LA stiffness did not change during the head lift and semi-curl-up compared to rest. In women without DRA, the LA was least stiff closest to the umbilicus; it increased in stiffness during the head lift and semi-curl-up and did not distort or change compared to rest.

CONCLUSION

Diastasis recti abdominis was associated with low LA stiffness and with LA distortion during a semi-curl-up task; the amount of distortion was a function of IRD and LA stiffness. J Orthop Sports Phys Ther 2019;49(9):656-665. Epub 26 Mar 2019. doi:10.2519/jospt.2019.8543.

Diastasis Recti Abdominis-diagnosis, Risk Factors, Effect on Musculoskeletal Function, Framework for Treatment and Implications for the Pelvic Floor

Background:

Diastasis Recti Abdominis (DRA) can occur during pregnancy and postpartum. It is defined as an increase of the inter-recti distance (IRD) beyond normal values. The diagnosis of DRA is inconsistent within the literature and varies depending on measurement instrument and activity during measurement (rest versus active curl-up). DRA is characterized by the stretching of linea alba (LA) and contributes to a protrusion of the anterior abdominal wall due to increased laxity in the myofascial system that supports abdominal viscera. DRA has been postulated to affect lumbopelvic support and function due to laxity of the LA and altered angle of muscle insertion, but recent studies have not confirmed this. Risk factors for the development of DRA have been investigated in pregnancy to 12-months postpartum.

Objective:

Rehabilitation for DRA has been traditionally focused on reducing the IRD, but recent research has proposed that a sole focus on closing the DRA is suboptimal.

Results:

It is important alongside the rehabilitation of the abdominal wall that there is the consideration of the pelvic floor (PF). In healthy individuals, with the activation of the transversus abdominis, there is a sub-maximal co-contraction of the PF muscles. This co-contraction can be lost or altered in women with urinary incontinence. An increase in intra-abdominal pressure without simultaneous co-contraction of the PF may cause caudal displacement of the PF.

Conclusion:

The aim of this review is to bring the reader up to date on the evidence on DRA and to propose a rehabilitation framework for the whole abdominal wall in DRA with consideration of the impact on the PF.

Comparison of Trunk Muscle Function Between Women With and Without Diastasis Recti Abdominis at 1 Year Postpartum

BACKGROUND

A separation of the abdominal muscles at the linea alba, known as diastasis recti abdominis (DRA), can occur after childbirth. However, the impact of DRA on abdominal muscle function is not clear.

OBJECTIVE

The objective was to determine if differences exist in trunk muscle function and self-reported pain and low back dysfunction between women with and without DRA at 12 to 14 months postpartum and if differences that emerge from the data are associated with the magnitude of the interrectus distance (IRD).

DESIGN

This study was a prospective, observational, case-control study.

METHODS

Women with (IRD ≥ 2.2 cm; n = 18) and without DRA (IRD < 2.2 cm; n = 22) participated. Maximal trunk flexion, extension, and rotation torque-generating capacity (Newton-meters), the Sit-Up test (0 to 3 points), and the Sitting-Rising Test (0 to 10 points), and trunk flexion, extension, and lateral flexion endurance (seconds) were measured. Pain and disability were assessed using numerical pain rating scales (0 to 100) and the Roland Morris Low Back Pain Questionnaire (0 to 24 points). Women were compared using independent t tests and Mann-Whitney U Tests. Pearson product-moment and Spearman rank correlation coefficients were used to determine associations; a = .05 was used for all tests.

RESULTS

Women with DRA demonstrated significantly lower trunk muscle rotation torque and scored lower on the sit-up test than those without DRA. IRD was negatively correlated with both trunk rotation torque (rho = -0.367) and sit-up test score (rho = -0.514).

LIMITATIONS

The results of this study should not be generalized to women who present with moderate-to-severe IRDs or to multiparous women.

CONCLUSION

The presence of DRA in primiparous women at 1 year postpartum is associated with trunk rotation strength and ability to perform a sit-up.

Influence of Ultrasound Transducer Tilt in the Cranial and Caudal Directions on Measurements of Inter-Rectus Distance in Parous Women

Purpose: An increased inter-rectus distance (IRD) can persist after a pregnancy and may be associated with lumbopelvic dysfunction. Ultrasound imaging (USI) is currently the gold standard for measuring IRD; however, no study has explored the need to standardize the transducer angle during these evaluations. The purpose of this study was to determine whether the angle of the ultrasound transducer relative to the underlying abdominal wall has an effect on measurements of IRD in parous women. Method: Ultrasound images of the linea alba (LA) were captured from 15 women, at rest and during a head lift, beginning with images acquired perpendicular to the LA at the midline, then tilted in 5° increments to 15° in both the cranial and the caudal directions. Repeated-measures analyses of variance were used to test for systematic differences in IRD measurements among the transducer angles in both the rest and the head-lift conditions. An α of 0.05 was used for all tests. Results: No significant effect of transducer angle was found in IRD measurements acquired with participants at rest (F_2.24,31.3=1.814; p=0.18) or during a head lift (F_3.15,44.1=1.315; p=0.28). Conclusion: When using USI, cranial or caudal tilt errors in transducer angle do not appear to pose a problem when measuring IRD.