This systematic review and meta-analysis were conducted according to the Cochrane Guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).
Search strategy and eligibility criteria
An online search was conducted in national and international databases, Medline, SID, Iran Medex, Magiran, Science, PubMed, Scopus, IranDoc, Web of Science, Cochrane, Direct CINAHL, and the Google Scholar search engine. It was conducted by two researchers individually until September 2022. In addition, we searched for randomized controlled trials (RCTs) and quasi-RCTs that evaluated the effect of KT on postpartum abdominal muscle recovery.
The search strategy was as follows: First, an initial limited search was performed from Medline, following the analysis of the title, abstract, and index terms used to describe the articles. Afterward, the search was performed using all identified keywords and index terms in all databases. The search strategy for each database was based on the target population, intervention, comparison, and outcome (PICO), including predefined database search terms (Mesh and Emtree) and manually added synonymous terms. The strategy search and Keywords included (Taping or Elastic Taping or Kinesio Taping) AND (postpartum or postpartum Women or women postpartum or puerperium) AND (Diastasis Recti) AND (Abdominal recovery). In the last step, the reference list of all articles was identified and searched for additional studies. Studies published in English or Persian and any date were considered for inclusion in this review. All analyzes were based on previously published studies. Reference lists of identified trials and systematic reviews were also searched.
Inclusion and exclusion criteria
The PICO criteria were as follows:
Population
Patients with abdominal disorders (Especially RAD (in the postpartum period.
Interventions
Patients received KT regardless of the duration of pain and treatment.
Comparison group
patients who did not receive any treatments or who used the methods of Exercise, physiotherapy, or electrical muscle stimulation.
Primary outcome
“Improvement of rectus abdominals."
The secondary outcome
"Improvement pain and low back dysfunction."
The exclusion criteria were as follows:
-
Cohort studies in any language other than English or Persian.
-
Non-experimental studies include case reports, case series, opinion articles, and observational studies.
-
The unavailability of the full-text version for articles and studies without peer review.
Outcome types
The primary outcome was an improvement in rectus abdominals. For this purpose, the examiners placed their fingers on the patient's umbilicus and pushed while the shoulders were on the floor; the patient raised the head about one inch. If there were any RAD, the examiner would feel a gap between the muscles about one inch (~ 2 fingers) or more.
The secondary outcome was improved pain and low back dysfunction due to the RAD. A visual analog scale (VAS) was used to measure the patient's pain before and after the intervention. VAS is a linear scale about 10 cm long, with the two ends of "0" and "10". 0 indicates no pain, and 10 means the most unbearable pain. Roland-Morris Dysfunction Questionnaire (RMDQ) was used to evaluate low back dysfunction. This questionnaire included 24 questions that were closely related to low back pain. "Yes" was assigned one point, and "No" was given 0 points for each question. The highest score was 24, and the lowest was 0. The higher the score, the more serious the back dysfunction[9].
Study Selection
After the searches, all identified citations were collected and uploaded to EndNote. Afterward, the duplicate studies were excluded. Each of the above steps was carried out by two researchers individually, and finally, the third researcher examined the agreement of the obtained results. The final systematic review fully reported the search results and presented them in the PRISMA flow chart (Fig. 1).
Data extraction
Two authors independently extracted the results of the selected articles. They presented the data extracted from each study, including the name of the first author, year of study publication, study design, type of intervention (Exercise, kinescope, electrical stimulation or without intervention), control group method, sample size, mean age, average symptom duration, intervention duration, each of the outcomes (Table 1). For eligible studies, two authors independently extracted data using the agreed form designed for extraction. Any disagreements would resolve through consultation with the third author.
Table 1
Characteristics of included studies
Study | Sample size (T/C) | Age (mean) | Postpartum (weeks) | Type of intervention | Duration of the trial period | Outcomes |
T / C |
Gursen et al. (2015 | 24 (12/12) | 29.26 ± 4.28 | between the fourth and sixth postnatal months | KT + exercise /exercise | Four weeks | The improvement observed in the KT + exercise group was significantly more significant compared to the exercise group regarding the strength of the rectus abdominal muscle, sit-up test, VAS, measurements of waist circumference, and RMDQ. |
Ptaszkowska et al (2021)17 | 10 (5/5) | 25.5 ± 5.8 | > 6 weeks and < 12 months | KT/ placebo | 48h | The gathered results show a statistically significant reduction in rectus abdominals diastasis at each of the observed sites after applying KT tapes in the intervention group. |
Hannan et al(2020)18 | 40(20/20) | 27.4 ± 1.19 | 2months | KT + exercise /exercise | 8weeks | The study findings concluded that KT added to Exercise is more effective than Exercise alone in reinforcing abdominal re-training in women who had a cesarean delivery. |
Maha M. Mady (2022)19 | 26 (26/26) | 29.26 ± 4.28 | 8 weeks | B A KT | 4weeks | A manual assessment of the distance between two recti was done to confirm the presence of DRAM. The reference points for DRAM measurement were three finger breadths (4.5 cm) above and below the umbilicus. The results of this study testified that KT is an effective method in reducing abdominal circumferences in postpartum women with or without DRAM |
Pournima et al (2020)20 | 200 (200/200) | 24.22 + 3.338 | Postpartum 1month | KT + exercise/exercise | 4 weeks | The abdominal strength pre and post-values were assessed with a sphygmomanometer. The disability was evaluated by Index (MODI) score. The study concluded that Kinesio Taping and Exercise's effect on diastasis recti is more effective than only exercises in postpartum women. |
Situ et al. (2021)21 | 40 (20/20) | Reproductive age | 6 weeks | Kt/NMES | 4 weeks | The results revealed significant improvement in both groups in all the measured parameters (p < 0.05). However, the intergroup comparisons showed significant improvement in all the measured parameters in group A (p < 0.05). |
Tuttle et al(2018)22 | 33 (10/7/5/8) | 32.03 ± 4.33 | 6 to 12 weeks postpartum | (Control, TRAexercise, tape, and TRA Exercise + tape) | 12-week | There was no significant difference between groups in IRD at the umbilicus, IRD above the umbilicus, RDQ scores, or PFDI-20 score at the initial time point (P > .05). Exercise targeting the TRA may be an effective treatment option to reduce IRD. No correlations were found between IRD and participants' self-reported Low back pain or pelvic floor dysfunction. |
Bobowik(2018)23 | 40 (20/20) | 32.32 ± 5.9 | 0–3 days postpartum | exercise and taping /no therapy | 6 weeks | After 6 weeks of using a new physiotherapeutic + kinesio taping, DRAM was reduced in 95% of women (19 people). For comparison, DRAM was spontaneously reduced in 15% (3 people) in the control group. |
Assessment of risk of bias in included studies
According to the Cochrane Manual for Systematic Reviews, the two authors assessed bias risk separately. Risk of bias assessment was performed through a six-criterion assessment checklist for random sequence generation, allocation concealment, blinding, incomplete outcome data, selective outcome reporting, and other sources of biases. In all cases, the assessment of "low or high risk" indicated the risk of bias, and "uncertain risk" indicated the uncertain risk of bias (Table 2, Fig. 2, Fig. 3).
ROBINS-, which is a risk-of-bias tool for evaluating non-randomized studies of interventions, was also used. It includes the following components before, during, and after the intervention; Bias in the selection of reported results, bias in the measurement of outcomes, bias due to missing data, bias due to deviations from intended interventions, bias in the classification of intervention, bias in the selection of participants, and bias due to confounding [10].(Table 3)
Table 2
Risk of Bias in Included RCT Studies
Bias | Authors' Judgment | Support for Judgment |
Gursen (2015) | | |
Random sequence generation (selection bias) | Low risk | Using the stratified block, postnatal women were randomly assigned into Exercise (n = 12) or KT + exercise (n = 12) groups. |
Allocation concealment (selection bias) | Low risk | Randomization procedure with opaque and sealed envelopes containing group allocation numbers from a computer-generated random number table. |
Blinding of personnel (performance bias) | High risk | It was not possible to blind the personnel. |
Blinding of participants (performance bias) | High risk | It was not possible to blind the participants. |
Blinding of outcome assessment (detection bias) | Low risk | All examinations were performed at baseline and the end The 4-week treatment by the same experienced physiotherapist (third author) blinded to the group allocation. |
Incomplete outcome data (attrition bias) | High risk | Of the 24 postnatal participants, 21 women completed the 4-week study period. Two women in the control group and one in the KT group dropped out of the study. |
Selective reporting (reporting bias) | Unclear risk | - |
Ptaszkowska (2021) | Authors' Judgment | Support for Judgment |
Random sequence generation (selection bias) | Low risk | Randomization was carried out using computer-generated random numbers (simple randomization). The participants were randomly assigned to groups in a 1:1 ratio. |
Allocation concealment (selection bias) | unclear risk | No specific information |
Blinding of personnel (performance bias) | Unclear risk | No specific information |
Blinding of participants (performance bias) | High risk | It was not possible to blind the participants |
Blinding of outcome assessment (detection bias) | Unclear risk | No specific information |
Incomplete outcome data (attrition bias) | Low risk | All participants completed the study |
Selective reporting (reporting bias) | Unclear risk | - |
Hannan (2020) | Authors' Judgment | Support for Judgment |
Random sequence generation (selection bias) | low risk | The women were divided randomly into two groups by a system of randomization. |
Allocation concealment (selection bias) | unclear risk | No specific information |
Blinding of personnel (performance bias) | High risk | It was not possible to blind the personnel. |
Blinding of participants (performance bias) | High risk | It was not possible to blind the participants. |
Blinding of outcome assessment (detection bias) | low risk | The assessor was blind about the group's assignment and wasn't involved in the treatment application |
Incomplete outcome data (attrition bias) | unclear risk | The diagram of the study process is not drawn, and it is not mentioned in the text |
Selective reporting (reporting bias) | unclear risk | |
Situ (2021) | Authors' Judgment | Support for Judgment |
Random sequence generation (selection bias) | low risk | The simple randomized method randomly divided all 40 subjects into two equal groups of 20 each |
Allocation concealment (selection bias) | unclear risk | No specific information regarding allocation concealment was given. |
Blinding of personnel (performance bias) | High risk | It was not possible to blind the personnel. |
Blinding of participants (performance bias) | High risk | It was not possible to blind the participants. |
Blinding of outcome assessment (detection bias) | Unclear risk | No specific information |
Incomplete outcome data (attrition bias) | unclear risk | The diagram of the study process is not drawn, and it is not mentioned in the text |
Selective reporting (reporting bias) | unclear risk | - |
Tuttle(2018) | Authors' Judgment | Support for Judgment |
Random sequence generation (selection bias) | low risk | Participants were randomly assigned to a group based on a computer-generated randomization schedule. |
Allocation concealment (selection bias) | unclear risk | No specific information regarding allocation concealment was given. |
Blinding of personnel (performance bias) | High risk | It was not possible to blind the personnel. |
Blinding of participants (performance bias) | High risk | It was not possible to blind the participants. |
Blinding of outcome assessment (detection bias) | low risk | The principal investigator conducting ultrasound measurements (first author) was blinded to group assignment throughout the study. |
Incomplete outcome data (attrition bias) | High risk | Thirty-three women were screened and enrolled; 3 did not complete the study because of loss to follow-up (n = 2) and new Pregnancy (n = 1). |
Selective reporting (reporting bias) | unclear risk | - |
Bobowik(2018) | Authors' Judgment | Support for Judgment |
Random sequence generation (selection bias) | low risk | Participants of the study were randomly assigned to one of two groups |
Allocation concealment (selection bias) | unclear risk | No specific information regarding allocation concealment was given. |
Blinding of personnel (performance bias) | High risk | It was not possible to blind the personnel. |
Blinding of participants (performance bias) | High risk | It was not possible to blind the participants. |
Blinding of outcome assessment (detection bias) | Unclear risk | No specific information |
Incomplete outcome data (attrition bias) | unclear risk | The diagram of the study process is not drawn, and it is not mentioned in the text |
Selective reporting (reporting bias) | unclear risk | |
Pournima(2020) | | |
Random sequence generation (selection bias) | High risk | 200 subjects were selected by convenient sampling method |
Allocation concealment (selection bias) | High risk | 200 subjects were selected by convenient sampling method |
Blinding of personnel (performance bias) | Unclear risk | No specific information |
Blinding of participants (performance bias) | Unclear risk | No specific information |
Blinding of outcome assessment (detection bias) | unclear risk | The diagram of the study process is not drawn, and it is not mentioned in the text |
Incomplete outcome data (attrition bias) | unclear risk | - |
Table 3
Risk of bias in non-randomized studies according to ROBINS-I.
Study | Pre-intervention | At intervention | Post-intervention | Overall Risk of Bias |
First Author. Year | Bias due to confounding | Bias in the selection of participants | Bias in the Classification of Interventions | Bias due to deviations from intended interventions | Bias due to missing data | Bias in the measurement of outcomes | Bias in the selection of reported result | Low/Moderate/ Serious/ Critical |
Mady(2022) | No information | Low | Moderate | Low | No information | Low | Low | Moderate |
Data synthesis and analysis
Meta-analysis was performed using Review Manager 5.3 statistical software (the Cochrane Collaboration, 2014, Nordic Cochrane Center, Copenhagen, Denmark). Mean changes and standard deviation (SD) in each group after the intervention compared to baseline were used to calculate MD change with a 95% Confidence Interval (CI) for meta-analysis. In addition, the degree of heterogeneity between the results of included studies was evaluated. This index shows the percentage of variation between studies; if it is more than 50%, it indicates high heterogeneity. Moreover, a random effect model was used instead of the fixed-effect model to report the meta-analysis[11].