INTRODUCTION
Diastasis rectus abdominis (DRA) is the relative displacement of the rectus abdominis muscles due to a widening of fascial connection that commonly occurs during pregnancy.1 2 1 3 4 5 6 7 8 8 Figure 1 .
Figure 1.: Schematic of the abdominal musculature. Illustrations represent abdominal musculature (A) without diastasis; (B) with open diastasis; (C) with open diastasis below the umbilicus; and (D) with open diastasis above the umbilicus.
The significant stretching of the linea alba disrupts the structural connectivity of the abdominal muscles,4 5 9 , 10 11
Core strengthening is thought to decrease DRA by causing greater contraction of the abdominal muscles, producing a stronger horizontal force that pulls the muscles together.12–14 13–16 17–21 22 , 23
The primary aim of this study was to assess changes in IRD following participation in a 12-week home exercise core strengthening program in postpartum women with DRA. The secondary aim was to investigate whether the core strengthening program affects symptoms that may be related to DRA, including LBP-related disability, SUI, pelvic floor dysfunction, and body image.
METHODS
Ethics
This prospective observational study was approved by the Institutional Review Board and was conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from all participants prior to any research activities.
Participant Recruitment
Participants were recruited through advertisements and flyers geared toward postpartum women. Advertisements and flyers were posted online on social media and local moms' groups, and information about the study was also distributed by word of mouth. Inclusion criteria required that participants be healthy women between the ages of 18 and 45 years who were not currently pregnant, were 12 weeks to 36 months postpartum, and had DRA with an IRD of at least 2.0 cm diagnosed using musculoskeletal ultrasound. Exclusion criteria included a history of ventral/umbilical hernia prior to pregnancy, current pregnancy, more than 36 months postpartum, a Beighton score (used to quantify joint laxity and mobility)24
Ultrasound Measurements
A single investigator performed all ultrasound screenings and measurements using a SonoSite X-Porte musculoskeletal ultrasound machine (Sonosite, Bothell, Washington). This investigator had 1 year of experience in performing IRD measurements and was trained by a fellowship-trained sports medicine physician with over 10 years of experience in musculoskeletal ultrasound. The measurements were performed in person in an outpatient office. IRD was measured at 3 cm above and below the umbilicus. Measurement sites were marked using a surgical skin marker. At each site, IRD was measured after a deep breath both at rest and during a head raise, which is thought to recruit the contraction of the rectus abdominus muscles.25 Figure 2 ). Three trials were collected at each location for both resting and contracted states. Representative ultrasound images are shown in Figure 3 . IRD measurements were collected at baseline and 12 weeks. Participants were included in the study if their IRD at rest, either above or below the umbilicus, was 2.0 cm or more. This cut-off for DRA was chosen based on ranges of IRD musculoskeletal ultrasound measurements in nulliparous women (1.0 cm above and 1.5 cm below the umbilicus26 6 3 23
Figure 2.: Images showing 2-cm head lifts and placement of the stadiometer.
Figure 3.: Interrectus distance (IRD) measured using SonoSite X-Porte Ultrasound in both resting and contracted states at 2 locations along the linea alba. (A) IRD at rest 3 cm above the umbilicus; (B) IRD during contraction 3 cm above the umbilicus; (C) IRD at rest 3 cm below the umbilicus; and (D) IRD during contraction 3 cm below the umbilicus.
Intraclass correlation coefficients (ICCs) were calculated to measure the reliability of measuring IRD via ultrasound. Reliability classifications were based on the following guidelines developed by Cicchetti et al27
Questionnaires
At the baseline appointment, each participant was asked to fill out a form containing demographics and medical history pertaining to their most recent pregnancy, the International Consultation of Incontinence-Urinary Incontinence Short Form (ICIQ-UI) to assess SUI,28 29 30 31 32 29 33 34 31 35
Intervention
The online, video-based core strengthening program was based on a previously reported exercise regimen for DRA36 Table 1 and are highlighted in the Supplementary Video, available at: https://links.lww.com/JWHPT/A48 37
Table 1. -
Online Core Strengthening Program Details
The 12-wk program is composed of core strengthening, supplementary workouts, and education.
Week
Education
Day
Primary Workouts: Core Training
Supplementary Workouts
1
Introduction to TrA muscle activation and abdominal draw in maneuver with cocontraction of the diaphragm and pelvic floor musculature.
1
5 min of “core compressions” performed in various positions (2 min in quadruped, 2 min seated upright against a wall, 1 min in a standing incline plank with hands against the wall).
20-min workout with an emphasis on total body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
2
6 min of “core compressions” performed in various body positions (2 min in quadruped, 2 min seated upright against a wall, 2 min in a wall-sit with neutral spine). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
3
7 min of “core compressions” performed in various body positions (2 min in quadruped, 1 min in standing incline plank with hands against the wall, 2 min in fetal position on the right side, 2 min in fetal position on the left side). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
22-min workout with an emphasis on total body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
4
7 min of “core compressions” performed in various body positions (2 min in quadruped, 2 min in seated upright, 1 min in standing incline plank, 2 min in wall-sit). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
5
8 min of “core compressions” performed in various body positions (2 min in quadruped, 2 min seated upright, 2 min in fetal position on the right side, 2 min in fetal position on the left side). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
29-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
6
9 min of “core compressions” performed in various body positions (2 min in quadruped, 1 min in standing incline plank, 2 min in fetal position on the right side, 2 min in fetal position on the left side, 2 min in supine with knees bent). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
13-min restorative workout that includes low-impact aerobic exercises, dynamic stretches, and light resistance exercises.
7
10 min of “core compressions” performed in various body positions (2 min in quadruped, 1 min in standing incline plank, 2 min in wall-sit, 1 min in standing incline plank [second set], 2 min in supine with knees bent, 2 min in quadruped [second set]). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
2
1
10 min of “core compressions” performed in various body positions (2 min in quadruped, 2 min seated upright, 2 min supine knees bent, 2 min supine spinal twist with knees to the right, 2 min supine spinal twist with knees to the left). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
17-min workout with an emphasis on lower body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
2
10 min of “core compressions” performed in various body positions (2 min quadruped, 2 min wall-sit, 2 min fetal right, 2 min fetal left, 2 min in partial supine-bridge). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
3
10 min of “core compressions” performed in various body positions (2 min in quadruped, 2 min in supine spinal twist right, 2 min in supine spinal twist left, 2 min in partial supine-bridge, 2 min in supine with ankles crossed and hips externally rotated). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
21-min workout with an emphasis on upper body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
4
9.5 min of “core compressions” performed in various body positions (2 min in quadruped, 2 min seated upright, 1 min standing incline wall plank, 2 min supine with ankles crossed and hips externally rotated, 2.5 min single-leg lifts with hip of active leg in external rotation). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
5
10 min of “core compressions” performed in various body positions (2 min quadruped, 2 min wall-sit, 2 min supine spinal twist right, 2 min supine spinal twist left, 2 min partial supine-bridge). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
21-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
6
10.5 min of “core compressions” performed in various body positions (2 min in quadruped, 2 min seated upright, 2 min supine with knees bent, 2 min supine with hips externally rotated and ankles crossed, 2.5 min with single-leg lifts, hip externally rotated). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
7
10.5 min of “core compressions” performed in various body positions (2 min in quadruped, 2 min supine spinal twist right, 2 min supine spinal twist left, 2 min partial supine-bridge, 2.5 min with single-leg lifts, hip externally rotated). Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature.
15-min restorative workout that includes low-impact aerobic exercises, dynamic stretches, and light resistance exercises.
3
1
10 min/d of exercises centered around the abdominal draw in maneuver (“core compressions”) in different positions. Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature. The positions include:
11-min workout with an emphasis on total body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
2
3
Quadruped
Seated upright against a wall
Standing incline plank with hands against the wall
Wall-sit with neutral spine
Fetal position on the right side
Fetal position on the left side
Supine with knees bent
Supine spinal twist with knees to the right
Supine spinal twist with knees to the left
Partial supine-bridge
Supine with ankles crossed and hips externally rotated
Single-leg lifts with hip of active leg in external rotation
16-min workout with an emphasis on upper body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
4
5
20-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
6
12-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
7
4
1
10 min/d of exercises centered around the abdominal draw in maneuver (“core compressions”) in different positions. Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature. The positions include:
23-min workout with an emphasis on lower body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
2
3
Quadruped
Seated upright against a wall
Standing incline plank with hands against the wall
Wall-sit with neutral spine
Fetal position on the right side
Fetal position on the left side
Supine with knees bent
Supine spinal twist with knees to the right
Supine spinal twist with knees to the left
Partial supine-bridge
Supine with ankles crossed and hips externally rotated
Single-leg lifts with hip of active leg in external rotation
22-min workout with an emphasis on upper body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
4
5
26-min workout with an emphasis lower body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
6
7
16-min restorative workout that includes low-impact aerobic exercises, dynamic stretches, and light resistance exercises.
5
1
10 min/d of exercises centered around the abdominal draw in maneuver (“core compressions”) in different positions. Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature. The positions include:
24-min workout with an emphasis on upper body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
2
3
Quadruped
Seated upright against a wall
Standing incline plank with hands against the wall
Wall-sit with neutral spine
Fetal position on the right side
Fetal position on the left side
Supine with knees bent
Supine spinal twist with knees to the right
Supine spinal twist with knees to the left
Partial supine-bridge
Supine with ankles crossed and hips externally rotated
Single-leg lifts with hip of active leg in external rotation
16-min workout with an emphasis on lower body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
4
5
13-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
6
7
12-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
6
1
10 min/d of exercises centered around the abdominal draw in maneuver (“core compressions”) in different positions. Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature. The positions include:
20-min workout with an emphasis on total body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
2
3
Quadruped
Seated upright against a wall
Standing incline plank with hands against the wall
Wall-sit with neutral spine
Fetal position on the right side
Fetal position on the left side
Supine with knees bent
Supine spinal twist with knees to the right
Supine spinal twist with knees to the left
Partial supine-bridge
Supine with ankles crossed and hips externally rotated
Single-leg lifts with hip of active leg in external rotation
25-min workout with an emphasis on total body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
4
5
20-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
6
12-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
7
7
1
10 min/d of exercises centered around the abdominal draw in maneuver (“core compressions”) in different positions. Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature. The positions include:
11-min workout with an emphasis on total body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
2
12-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
3
Quadruped
Seated upright against a wall
Standing incline plank with hands against the wall
Wall-sit with neutral spine
Fetal position on the right side
Fetal position on the left side
Supine with knees bent
Supine spinal twist with knees to the right
Supine spinal twist with knees to the left
Partial supine-bridge
Supine with ankles crossed and hips externally rotated
Single-leg lifts with hip of active leg in external rotation
4
22-min workout with an emphasis on total body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
5
6
25-min workout with an emphasis on total body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
7
8
1
10 min/d of exercises centered around the abdominal draw in maneuver (“core compressions”) in different positions. Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature. The positions include:
26-min workout with an emphasis on lower body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
2
3
Quadruped
Seated upright against a wall
Standing incline plank with hands against the wall
Wall-sit with neutral spine
Fetal position on the right side
Fetal position on the left side
Supine with knees bent
Supine spinal twist with knees to the right
Supine spinal twist with knees to the left
Partial supine-bridge
Supine with ankles crossed and hips externally rotated
Single-leg lifts with hip of active leg in external rotation
22-min workout with an emphasis on upper body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
4
5
21-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
6
7
17-min restorative workout that includes low-impact aerobic exercises, dynamic stretches, and light resistance exercises.
9
1
10 min/day of exercises centered around the abdominal draw in maneuver (“core compressions”) in different positions. Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature. The positions include:
25-min workout with an emphasis on total body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
2
3
Quadruped
Seated upright against a wall
Standing incline plank with hands against the wall
Wall-sit with neutral spine
Fetal position on the right side
Fetal position on the left side
Supine with knees bent
Supine spinal twist with knees to the right
Supine spinal twist with knees to the left
Partial supine-bridge
Supine with ankles crossed and hips externally rotated
Single-leg lifts with hip of active leg in external rotation
21-min workout with an emphasis on upper body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
4
5
20-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
6
24-min workout with an emphasis on lower body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
7
10
1
10 min/d of exercises centered around the abdominal draw in maneuver (“core compressions”) in different positions. Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature. The positions include:
16-min workout with an emphasis on upper body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
2
3
Quadruped
Seated upright against a wall
Standing incline plank with hands against the wall
Wall-sit with neutral spine
Fetal position on the right side
Fetal position on the left side
Supine with knees bent
Supine spinal twist with knees to the right
Supine spinal twist with knees to the left
Partial supine-bridge
Supine with ankles crossed and hips externally rotated
Single-leg lifts with hip of active leg in external rotation
23-min workout with an emphasis on lower body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
4
5
12-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
6
25-min workout with an emphasis on total body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
7
11
1
10 min/d of exercises centered around the abdominal draw in maneuver (“core compressions”) in different positions. Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature. The positions include:
24-min workout with an emphasis on upper body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
2
3
Quadruped
Seated upright against a wall
Standing incline plank with hands against the wall
Wall-sit with neutral spine
Fetal position on the right side
Fetal position on the left side
Supine with knees bent
Supine spinal twist with knees to the right
Supine spinal twist with knees to the left
Partial supine-bridge
Supine with ankles crossed and hips externally rotated
Single-leg lifts with hip of active leg in external rotation
16-min workout with an emphasis on lower body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
4
5
13-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
6
7
26-min workout with an emphasis on lower body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
12
Education about what exercises to skip/modify to avoid reinjury if they choose to resume workouts and activities outside the program.
1
10 min/d of exercises centered around the abdominal draw in maneuver (“core compressions”) in different positions. Video coaching includes reminders to coordinate TrA muscle contraction with exhalation and engagement of the pelvic floor musculature. The positions include:
15-min restorative workout that includes low-impact aerobic exercises, dynamic stretches, and light resistance exercises.
2
20-min workout with an emphasis on total body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
3
Quadruped
Seated upright against a wall
Standing incline plank with hands against the wall
Wall-sit with neutral spine
Fetal position on the right side
Fetal position on the left side
Supine with knees bent
Supine spinal twist with knees to the right
Supine spinal twist with knees to the left
Partial supine-bridge
Supine with ankles crossed and hips externally rotated
Single-leg lifts with hip of active leg in external rotation
4
25-min workout with an emphasis on total body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
5
20-min workout with an emphasis on core strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
6
16-min workout with an emphasis on upper body strength that incorporates low-impact aerobic exercises, resistance exercises, and gentle stretches.
7
Compliance
All participants were required to complete weekly training logs for the duration of the study. Adherence was monitored by an investigator who was able to observe the frequency with which each participant logged into the exercise program software and if they had watched or engaged with specific videos. This investigator did not do any of the ultrasound measurements. Compliance was defined as performing 50% or more of the online core strengthening exercises throughout the 12-week period. This was determined by engagement per day, so those who performed multiple days' worth of exercises on 1 day were only counted as having completed 1 day of exercises. Similar methods of assessing compliance have been used in other studies.38–40
Statistical Methods
All data were stored and maintained on REDCap.41 , 42 https://links.lww.com/JWHPT/A50 t test was performed. A Bonferroni correction was applied to the family of tests with IRD as the dependent variable. Comparisons of baseline characteristics between included and withdrawn participants, as well as between the maintenance phase subset and the remaining sample, were analyzed using the 2-sample t test for continuous variables and Pearson's χ2 test for discrete variables. Statistical significance was defined as P < .05, unless otherwise indicated. All analyses were performed with Stata, version 14.2 (StataCorp, College Station, Texas).43
RESULTS
Study Recruitment
One hundred twenty-six postpartum women expressed interest in participating between July and November 2018. Seventy women were excluded because they did not meet eligibility criteria. Fifty-six women were initially enrolled (n = 56). Thirteen women were withdrawn; 6 never engaged in the core strengthening program (ie, no activity on exercise program software), 6 stopped participating abruptly and failed to respond to multiple requests to continue program engagement and/or complete weekly training logs, and 1 found out she was pregnant. No follow-up data related to the 12-week program could be obtained from these women, and they were thus excluded from the analysis (Figure 4 ).
Figure 4.: Participant flow diagram. The numbers of participants who were assessed, received the intervention, and underwent data analysis are shown. Reasons for exclusion/withdrawal are provided.
Baseline Group Characteristics
Forty-three participants were included in the analysis, with a mean age of 36.7 ± 3.5 years and a mean BMI of 22.9 ± 3.0 kg/m2 . Baseline characteristics are shown in Table 2 . The mean number of weeks postpartum was 66.8 ± 42.7 weeks, and 22 participants (51%) were currently breastfeeding. Nineteen participants completed the additional 12-week maintenance phase. There were no differences in baseline characteristics between participants who were included in the analysis and participants who were withdrawn due to lack of engagement in the program (see Supplementary Table 1, available at: https://links.lww.com/JWHPT/A49 https://links.lww.com/JWHPT/A49
Table 2. -
Demographics and Baseline Information
Overall (n = 43)
Age, mean (SD), y
36.7 (3.5)
BMI, mean (SD), kg/m2
22.9 (3.0)
Number of weeks postpartum, mean (SD)
66.8 (42.7)
Number of pregnancies, n (%)
1
12 (28)
2
12 (28)
3
8 (19)
4
5 (12)
5
5 (12)
6
1 (2)
Multiple gestation pregnancies, n (%)
4 (9)
Number of vaginal deliveries, n (%)
1
8 (19)
2
10 (23)
3
10 (23)
4
1 (2)
5
2 (5)
Number of C-sections, n (%)
1
12 (28)
2
2 (5)
3
1 (2)
Currently breastfeeding, n (%)
22 (51)
History of abdominal surgery, n (%)
7 (16)
IRD above umbilicus, at rest, mean (SD), cm
3.5 (1.1)
IRD above umbilicus, contracted, mean (SD), cm
3.0 (1.0)
IRD below umbilicus, at rest, mean (SD), cm
2.2 (0.8)
IRD below umbilicus, contracted, mean (SD), cm
2.1 (0.8)
LBP-related disability score (QBPDS), mean (SD)
7.8 (10.6)
Stress urinary incontinence score (ICIQ-UI), mean (SD)
3.3 (3.2)
Pelvic floor function score (PISQ-12), mean (SD)
37.3 (4.0)
Body image score (BSQ-16A), mean (SD)
38.0 (12.0)
Abbreviations: BMI, body mass index; BSQ-16A, Body Shape Questionnaire; C-section, cesarean section; ICIQ-UI, International Consultation on Incontinence Questionnaire-Urinary Incontinence; IRD, interrectus distance; PISQ-12, Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Question; QBPDS, Quebec Back Pain Disability Scale; SD, standard deviation.
IRD Measurement Reliability
ICCs for IRD values above the umbilicus were 0.817 at rest and 0.865 during contraction; both were classified as “excellent.” Below the umbilicus, ICCs for IRD values were 0.567 at rest and 0.681 during contraction. The ICC for IRD value at rest below the umbilicus was classified as “fair,” whereas the ICC for IRD value during contraction below the umbilicus was classified as “good.”
12-Week Core Strengthening Program and IRD Measurements
For IRD above the umbilicus, a significant improvement was observed at rest (slope [SD]: −0.56 [0.09]; 95% confidence interval [CI]: −0.74, −0.38; P < .001) following participation in the 12-week online core strengthening program. An improvement was also observed during contraction, but this did not reach statistical significance (slope [SD]: −0.24 [0.12]; 95% CI: −0.47, 0.01; P = .037). For IRDs below the umbilicus, significant improvements were observed at rest (slope [SD]: −0.26 [0.10]; 95% CI: −0.45, −0.06; P = .009) and during contraction (slope [SD]: −0.39 [0.10]; 95% CI: −0.58, −0.20; P < .001) (Table 3 ).
Table 3. -
Effect of 12-Week Core Strengthening Program on Changes in IRD and PROs
Variables
Slope (SD)
95% CI
P Valuea
IRD above umbilicus, at rest, cm
−0.56 (0.09)
−0.74, −0.38
<.001
IRD below umbilicus, at rest, cm
−0.26 (0.10)
−0.45, −0.06
.009
IRD above umbilicus, during contraction, cm
−0.24 (0.12)
−0.47, 0.01
.037
IRD below umbilicus, during contraction, cm
−0.39 (0.10)
−0.58, −0.20
<.001
LBP-related disability score (QBPDS)
−3.28 (1.08)
−5.39, −1.17
.002
Stress urinary incontinence score (ICIQ-UI)
−0.74 (0.22)
−1.16, −0.31
.001
Pelvic floor function score (PISQ-12)
1.36 (1.01)
−0.62, 3.43
.177
Body image score (BSQ-16A)
1.22 (1.52)
−1.76, 4.21
.422
Abbreviations: BSQ-16A, Body Shape Questionnaire; CI, confidence interval; ICIQ-UI, International Consultation on Incontinence Questionnaire-Urinary Incontinence; IRD, interrectus distance; PISQ-12, Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Question; PRO, participant-reported outcome; QBPDS, Quebec Back Pain Disability Scale; SD, standard deviation.
a Italics signify Bonferroni-adjusted α/4 = 0.0125.
Secondary Outcomes at 12 Weeks
There were significant decreases in LBP-related disability (QBPDS; slope [SD]: −3.28 [1.08]; 95% CI: −5.39, −1.17; P = .002) and SUI (ICIQ-UI; slope [SD]: −0.74 [0.22]; 95% CI: −1.16, −0.31; P = .001) following participation in the 12-week online core strengthening programs. No differences in pelvic floor function (PISQ-12) and body image (BSQ) were observed (P = .177 and .422, respectively) (Table 3 ). Additionally, there was no association between IRD measurements and program compliance, multiple gestation pregnancies, or satisfaction.
IRD Measurements and Participant-Reported Outcomes After 12-Week Core Strengthening and 12-Week Maintenance
During the maintenance phase, participants continued with the core strengthening program for an additional 12 weeks. For these 19 participants, outcomes were compared at 24 weeks versus 12 weeks. At 24 weeks, all IRD measurements, except for IRD above the umbilicus during contraction, were significantly lower than those at 12 weeks (P = .007 for IRD above at rest, P < .001 for IRD below at rest, P < .001 for IRD below during contraction). IRD above the umbilicus during contraction was also lower at 24 weeks compared with 12 weeks, but this change was not statistically significant (P = .065). Representative ultrasound images depicting IRD measurements at baseline, 12 weeks, and 24 weeks are shown in Figure 5 . There were no differences in any of the participant-reported outcomes following the maintenance phase at 24 weeks, compared with those at 12 weeks (Table 4 ).
Figure 5.: Representative IRD measurements at rest 3 cm above the umbilicus for an individual at (A) baseline; (B) 12 weeks (after participation in the core strengthening program); and (C) 24 weeks (after participation in the maintenance phase).
Table 4. -
Comparison of IRD and PROs After Initial 12-Week Core Strengthening Program and 12-Week Maintenance Phase
Variables
12 wka
24 wka
P Valueb
IRD above umbilicus, at rest, cm
3.5 (1.2)
2.8 (0.6)
.007
IRD below umbilicus, at rest, cm
2.2 (0.8)
1.5 (0.5)
<.001
IRD above umbilicus, during contraction, cm
3.1 (1.3)
2.6 (0.6)
.065
IRD below umbilicus, during contraction, cm
2.0 (0.7)
1.4 (0.4)
<.001
LBP-related disability score (QBPDS)
8.6 (11.1)
6.4 (8.0)
.153
Stress urinary incontinence score (ICIQ-UI)
2.3 (1.7)
1.6 (2.0)
.109
Pelvic floor function score (PISQ-12)
44.6 (2.9)
43.6 (3.3)
.493
Body image score (BSQ-16A)
36.0 (12.0)
38.6 (15.9)
.456
Abbreviations: BSQ-16A, Body Shape Questionnaire; ICIQ-UI, International Consultation on Incontinence Questionnaire-Urinary Incontinence; IRD, interrectus distance; LBP, low back pain; PISQ-12, Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Question; PRO, participant-reported outcomes; QBPDS, Quebec Back Pain Disability Scale.
a Results are mean (standard deviation) of n = 19; 24 weeks denotes the end of the 12-week maintenance phase.
b Italics signify Bonferroni-adjusted α/4 = 0.0125.
Program Compliance and Satisfaction
Program compliance was reported by 72% of participants (n = 31). Forty participants answered the satisfaction questions. The overall mean satisfaction was 7.43 ± 2.23 on a scale of 0 to 10. Thirty-eight participants (95%) stated that they would recommend the exercise program to a friend.
DISCUSSION
This prospective observational study assessed IRD and participant-reported outcomes following an online, video-based core strengthening program in postpartum women with DRA. IRD measurements at rest were significantly reduced after 12 weeks of the online core strengthening program. Those who completed the program for 12 weeks and then participated in an additional 12-week maintenance phase had significantly greater improvements in their IRD at 24 weeks. There were also significant improvements in LBP-related disability and SUI following the 12-week core strengthening program. Satisfaction with the program was high overall.
Prior work has demonstrated that core strengthening improves DRA, but there is no consensus on the optimal timing, duration, frequency, and type of exercises to correct this issue. In postpartum women, IRD has been shown to decrease while performing an abdominal crunch, but no data exist regarding the long-term effect of this exercise on IRD.11 , 44 13–16
In our study, the IRD improvements at 12 and 24 weeks were statistically significant above the umbilicus at rest and below the umbilicus at rest and during contraction. Although not statistically significant, there was also a decrease in IRD above the umbilicus during contraction. Importantly, participants who continued the exercises during an additional 12-week maintenance phase demonstrated significantly lower IRD measurements at 24 weeks compared with 12 weeks. Most women did not see full resolution of their IRD, according to the clinical definition of a separation less than 2 cm. However, data on prepartum IRDs for each participant were not available. Mean IRDs in nulliparous women have been shown to be 2.2 cm at 3 cm above the umbilicus and 1.6 cm at 2 cm below the umbilicus.6
In addition, LBP-related disability and SUI were significantly improved following the 12-week core strengthening program. No differences in pelvic floor function and body image were observed. Unlike IRD, no further significant improvements in LBP-related disability and SUI were observed after the 12-week maintenance phase. It is important to note that disability was low at baseline in this cohort, which may not be representative of the general postpartum population. Most participants were highly motivated and may have been more eager to exercise, compared with those who may suffer considerably from any of these DRA-related sequelae. Furthermore, it is important to note that there is conflicting evidence in the literature with regard to the relationship between DRA and LBP or SUI.45 46 47 2 , 10 , 48 49 50 51 , 52
This study adds to the limited studies evaluating DRA in postpartum women. The online core strengthening program offers advantages over a hands-on exercise program, as it can be utilized by a greater number of women and can be accessed at any time. This can be especially useful in the current setting of the COVID-19 pandemic, which has led to an increase in the shift from in-person to virtual exercise or rehabilitation programs overall.53 54
Our findings should be considered in the context of the limitations of the study. First, we had to withdraw 13 women due to lack of participation in the program activity and/or lack of response to weekly logs, which reduced our sample size. It is important to note that no follow-up data were collected from these women, so there was no way to include data from these subjects in an intention-to-treat analysis. Second, there is no agreement as to the width of IRD that is considered to be pathologic. Our cut-off of 2.0 cm might have been too broad, leading to the possible inclusion of women with “normal” IRDs. In addition, because all exercise instructions were provided online through videos, there was no way to ensure that participants were performing the exercises correctly. However, the instructions were repeated during each online session. Furthermore, since the participants were doing the exercises on their own, we had to estimate subject compliance by tracking subjective measures of self-reported participation and when they logged on to do the exercises. This definition of compliance was adapted from existing studies,38 , 40
CONCLUSIONS
Findings from this study show that a 12-week online core strengthening program, which emphasized isometric recruitment of the transversus abdominis while excluding common forward-flexion exercises (ie, sit-ups, crunches, and crossover crunches), significantly decreased IRD above and below the umbilicus in this cohort of postpartum women. Participation in the exercises for an additional 12 weeks led to a greater decrease in IRD. In addition, satisfaction with the program was high overall, and most participants reported that they would refer the program to a friend. As evidenced by the large number of women who expressed interest in this study within a short period of time, DRA is a huge area of concern for postpartum women. Thus, the online core strengthening program has great potential to improve DRA in postpartum women in a time- and cost-effective manner, as it can be accessed without the need for specific time commitments to in-person sessions. Furthermore, LBP-related disability and SUI have a high burden in postpartum women, and the online core strengthening program effectively improved both conditions in this cohort. Our findings suggest that a video-based core strengthening exercise program offers an accessible and effective treatment strategy for postpartum women with DRA, and further investigation regarding the optimal timing, duration, and sequence of exercises is warranted.
REFERENCES
1. Boissonnault JS, Blaschak MJ. Incidence of diastasis recti abdominis during the childbearing year. Phys Ther. 1988;68(7):1082–1086.
2. Sperstad JB, Tennfjord MK, Hilde G, Ellstrom-Engh M, Bø K. Diastasis recti abdominis during pregnancy and 12 months after childbirth: prevalence, risk factors and report of lumbopelvic pain. Br J Sports Med. 2016;50(17):1092–1096. doi:10.1136/bjsports-2016-096065.
3. Chiarello CM, McAuley JA, Hartigan EH. Immediate effect of active abdominal contraction on inter-recti distance. J Orthop Sports Phys Ther. 2016;46(3):177–183. doi:10.2519/jospt.2016.6102.
4. Gilleard WL, Brown JM. Structure and function of the abdominal muscles in primigravid subjects during pregnancy and the immediate postbirth period. Phys Ther. 1996;76(7):750–762. doi:10.1093/ptj/76.7.750.
5. Lo T, Candido G, Janssen P. Diastasis of recti abdominis in pregnancy: risk factors and treatment. Physiother Can. 1999;51:32–36, 44.
6. Beer GM, Schuster A, Seifert B, Manestar M, Mihic-Probst D, Weber SA. The normal width of the linea alba in nulliparous women. Clin Anat. 2009;22(6):706–711. doi:10.1002/ca.20836.
7. Candido G, Lo T, Janssen PA. Risk factors for diastasis of the recti abdominis. J Chart Physiother Women's Health. 2005;97:49–54.
8. Mota P, Pascoal AG, Carita AI, Bø K. Normal width of the inter-recti distance in pregnant and postpartum primiparous women. Musculoskelet Sci Pract. 2018;35:34–37. doi:10.1016/j.msksp.2018.02.004.
9. Parker MA, Millar LA, Dugan SA. Diastasis rectus abdominis and lumbo-pelvic pain and dysfunction-are they related? J Womens Health Phys Ther. 2009;33(2):15–22.
10. Keshwani N, Mathur S, McLean L. Relationship between inter-rectus distance and symptom severity in women with diastasis recti in the early postpartum period. Phys Ther. 2018;98(3):182–190. doi:10.1093/ptj/pzx117.
11. Mota P, Pascoal AG, Carita AI, Bø K. The immediate effects on inter-rectus distance of abdominal crunch and drawing-in exercises during pregnancy and the postpartum period. J Orthop Sports Phys Ther. 2015;45(10):781–788. doi:10.2519/jospt.2015.5459.
12. Pascoal AG, Dionisio S, Cordeiro F, Mota P. Inter-rectus distance in postpartum women can be reduced by isometric contraction of the abdominal muscles: a preliminary case-control study. Physiotherapy. 2014;100(4):344–348. doi:10.1016/j.physio.2013.11.006.
13. Thabet AA, Alshehri MA. Efficacy of deep core stability exercise program in postpartum women with diastasis recti abdominis: a randomised controlled trial. J Musculoskelet Neuronal Interact. 2019;19(1):62–68.
14. Walton LM, Costa A, LaVanture D, McIlrath S, Stebbins B. The effects of a 6 week dynamic core stability plank exercise program compared to a traditional supine core stability strengthening program on diastasis recti abdominis closure, pain, Oswestry disability index (ODI) and pelvic floor disability index scores (PFDI). Phys Ther Rehabil. 2016;3(1):3. doi:10.7243/2055-2386-3-3.
15. Gluppe SL, Hilde G, Tennfjord MK, Engh ME, Bø K. Effect of a postpartum training program on prevalence of diastasis recti abdominis in postpartum primiparous women: a randomized controlled trial. Phys Ther. 2018;98(4):260–268. doi:10.1093/ptj/pzy008.
16. Deering RE, Chumanov ES, Stiffler-Joachim MR, Heiderscheit BC. Exercise program reduces inter-recti distance in female runners up to 2 years postpartum. J Womens Health Phys Ther. 2020;44(1):9–18. doi:10.1097/jwh.0000000000000157.
17. Mota P, Pascoal AG, Sancho F, Carita AI, Bø K. Reliability of the inter-rectus distance measured by palpation. Comparison of palpation and ultrasound measurements. Man Ther. 2013;18(4):294–298. doi:10.1016/j.math.2012.10.013.
18. Mota P, Pascoal AG, Sancho F, Bø K. Test-retest and intrarater reliability of 2-dimensional ultrasound measurements of distance between rectus abdominis in women. J Orthop Sports Phys Ther. 2012;42(11):940–946. doi:10.2519/jospt.2012.4115.
19. van de Water AT, Benjamin DR. Measurement methods to assess diastasis of the rectus abdominis muscle (DRAM): a systematic review of their measurement properties and meta-analytic reliability generalisation. Man Ther. 2016;21:41–53. doi:10.1016/j.math.2015.09.013.
20. Nahabedian MY, Nahabedian AG. Closing the gap for patients with rectus abdominis diastasis. Nursing. 2018;48(1):49–52. doi:10.1097/01.Nurse.0000527601.09592.14.
21. Gluppe SB, Engh ME, Bø K. Immediate effect of abdominal and pelvic floor muscle exercises on interrecti distance in women with diastasis recti abdominis who were parous. Phys Ther. 2020;100(8):1372–1383. doi:10.1093/ptj/pzaa070.
22. Mendes Dde A, Nahas FX, Veiga DF, et al. Ultrasonography for measuring rectus abdominis muscles diastasis. Acta Cir Bras. 2007;22(3):182–186.
23. Keshwani N, McLean L. Ultrasound imaging in postpartum women with diastasis recti: intrarater between-session reliability. J Orthop Sports Phys Ther. 2015;45(9):713–718. doi:10.2519/jospt.2015.5879.
24. Beighton P, Horan F. Orthopaedic aspects of the Ehlers-Danlos syndrome. J Bone Joint Surg Br. 1969;51(3):444–453.
25. Lee D, Hodges PW. Behavior of the linea alba during a curl-up task in diastasis rectus abdominis: an observational study. J Orthop Sports Phys Ther. 2016;46(7):580–589. doi:10.2519/jospt.2016.6536.
26. Rath AM, Attali P, Dumas JL, Goldlust D, Zhang J, Chevrel JP. The abdominal linea alba: an anatomo-radiologic and biomechanical study. Surg Radiol Anat. 1996;18(4):281–288. doi:10.1007/bf01627606.
27. Cicchetti DV, Sparrow SA. Developing criteria for establishing interrater reliability of specific items: applications to assessment of adaptive behavior. Am J Ment Defic. 1981;86(2):127–137.
28. Avery K, Donovan J, Peters TJ, Shaw C, Gotoh M, Abrams P. ICIQ: a brief and robust measure for evaluating the symptoms and impact of urinary incontinence. Neurourol Urodyn. 2004;23(4):322–330. doi:10.1002/nau.20041.
29. Rogers RG, Coates KW, Kammerer-Doak D, Khalsa S, Qualls C. A short form of the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12). Int Urogynecol J Pelvic Floor Dysfunct. 2003;14(3):164–168; discussion 168. doi:10.1007/s00192-003-1063-2.
30. Cooper PJ, Taylor MJ, Cooper Z, Fairbum CG. The development and validation of the Body Shape Questionnaire. Int J Eat Disord. 1987;6(4):485–494. doi:10.1002/1098-108x(198707)6:4<485::aid-eat2260060405>3.0.co;2-o.
31. Kopec JA, Esdaile JM, Abrahamowicz M, et al. The Quebec Back Pain Disability Scale. Measurement properties. Spine (Phila Pa 1976). 1995;20(3):341–352. doi:10.1097/00007632-199502000-00016.
32. Slavin V, Gamble J, Creedy DK, Fenwick J. Perinatal incontinence: psychometric evaluation of the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form and Wexner Scale. Neurourol Urodyn. 2019;38(8):2209–2223. doi:10.1002/nau.24121.
33. Rosen JC, Jones A, Ramirez E, Waxman S. Body Shape Questionnaire: studies of validity and reliability. Int J Eat Disord. 1996;20(3):315–319. doi:10.1002/(sici)1098-108x(199611)20:3<315::Aid-eat11>3.0.Co;2-z.
34. Lee MF, Williams SL, Burke KJ. Striving for the thin ideal post-pregnancy: a cross-sectional study of intuitive eating in postpartum women. J Reprod Infant Psychol. 2020;38(2):127–138. doi:10.1080/02646838.2019.1607968.
35. Ronchetti I, Vleeming A, van Wingerden JP. Physical characteristics of women with severe pelvic girdle pain after pregnancy: a descriptive cohort study. Spine (Phila Pa 1976). 2008;33(5):E145–E151. doi:10.1097/BRS.0b013e3181657f03.
36. Sharma G, Lobo T, Keller L. Postnatal exercise can reverse diastasis recti. Obstet Gynecol. 2014;123:171S. doi:10.1097/01.AOG.0000447180.36758.7a.
37. Dufour S, Bernard S, Murray-Davis B, Graham N. Establishing expert-based recommendations for the conservative management of pregnancy-related diastasis rectus abdominis: a Delphi consensus study. J Womens Health Phys Ther. 2019;43(2).
38. Minett MM, Binkley TL, Holm RP, Runge M, Specker BL. Feasibility and effects on muscle function of an exercise program for older adults. Med Sci Sports Exerc. 2020;52(2):441–448. doi:10.1249/mss.0000000000002152.
39. Cnossen IC, van Uden-Kraan CF, Witte BI, et al. Prophylactic exercises among head and neck cancer patients during and after swallowing sparing intensity modulated radiation: adherence and exercise performance levels of a 12-week guided home-based program. Eur Arch Otorhinolaryngol. 2017;274(2):1129–1138. doi:10.1007/s00405-016-4367-9.
40. Emerenziani GP, Gallotta MC, Migliaccio S, et al. Effects of an individualized home-based unsupervised aerobic training on body composition and physiological parameters in obese adults are independent of gender. J Endocrinol Invest. 2018;41(4):465–473. doi:10.1007/s40618-017-0771-2.
41. Harris PA, Taylor R, Minor BL, et al. The REDCap consortium: building an international community of software platform partners. J Biomed Inform. 2019;95:103208. doi:10.1016/j.jbi.2019.103208.
42. Harris PA, Taylor R, Thielke R, Payne J, Gonzalez N, Conde JG. Research electronic data capture (REDCap)—a metadata-driven methodology and workflow process for providing translational research informatics support. J Biomed Inform. 2009;42(2):377–381. doi:10.1016/j.jbi.2008.08.010.
43. Stata Statistical Software: Release 14 [computer program]. College Station, TX: StataCorp LP; 2015.
44. Sancho MF, Pascoal AG, Mota P, Bø K. Abdominal exercises affect inter-rectus distance in postpartum women: a two-dimensional ultrasound study. Physiotherapy. 2015;101(3):286–291. doi:10.1016/j.physio.2015.04.004.
45. Benjamin DR, van de Water AT, Peiris CL. Effects of exercise on diastasis of the rectus abdominis muscle in the antenatal and postnatal periods: a systematic review. Physiotherapy. 2014;100(1):1–8. doi:10.1016/j.physio.2013.08.005.
46. Doubkova L, Andel R, Palascakova-Springrova I, Kolar P, Kriz J, Kobesova A. Diastasis of rectus abdominis muscles in low back pain patients. J Back Musculoskelet Rehabil. 2018;31(1):107–112. doi:10.3233/bmr-169687.
47. Santos MDD, Silva RDM, Vicente MP, Palmezoni VP, Carvalho EMD, Resende APM. A dimensão da diástase abdominal tem influência sobre a dor lombar durante a gestação? Revista Dor. 2016;17:43–46.
48. Fernandes da Mota PG, Pascoal AG, Carita AI, Bø K. Prevalence and risk factors of diastasis recti abdominis from late pregnancy to 6 months postpartum, and relationship with lumbo-pelvic pain. Man Ther. 2015;20(1):200–205. doi:10.1016/j.math.2014.09.002.
49. Olsson A, Kiwanuka O, Wilhelmsson S, Sandblom G, Stackelberg O. Cohort study of the effect of surgical repair of symptomatic diastasis recti abdominis on abdominal trunk function and quality of life. BJS Open. 2019;3(6):750–758. doi:10.1002/bjs5.50213.
50. Blyholder L, Chumanov E, Carr K, Heiderscheit B. Exercise behaviors and health conditions of runners after childbirth. Sports Health. 2017;9(1):45–51. doi:10.1177/1941738116673605.
51. Braga A, Caccia G, Nasi I, et al. Diastasis recti abdominis after childbirth: is it a predictor of stress urinary incontinence? J Gynecol Obstet Hum Reprod. 2019:101657. doi:10.1016/j.jogoh.2019.101657.
52. Wang Q, Yu X, Chen G, Sun X, Wang J. Does diastasis recti abdominis weaken pelvic floor function? A cross-sectional study. Int Urogynecol J. 2020;31(2):277–283. doi:10.1007/s00192-019-04005-9.
53. Bashshur R, Doarn CR, Frenk JM, Kvedar JC, Woolliscroft JO. Telemedicine and the COVID-19 pandemic, lessons for the future. Telemedicine J E Health. 2020;26(5):571–573. doi:10.1089/tmj.2020.29040.rb.
54. Axer H, Keyserlingk DG, Prescher A. Collagen fibers in linea alba and rectus sheaths. I. General scheme and morphological aspects. J Surg Res. 2001;96(1):127–134. doi:10.1006/jsre.2000.6070.
