Materials and Methods
PROMOTE was a randomized, controlled clinical trial. Study visits were conducted from 2007-2011, at 3 Obstetrics and Gynecology clinics in Tarrant County, TX. The Institutional Review Boards at the University of North Texas Health Science Center and John Peter Smith Health Network approved the study. Clinic personnel referred interested women to the research coordinators for screening. Eligible women 18-35 years old who had reached gestational week 30 and were willing to participate were consented and enrolled ( Figure 1 ). Women with high-risk conditions, as determined by their obstetrics provider, were excluded. High-risk conditions included, but were not limited to, preeclampsia/eclampsia, vaginal bleeding, oligohydramnios, gestational diabetes mellitus, and hypertension. Women were withdrawn from the study if their obstetrics provider identified a high-risk condition during their participation. Women were also unable to continue in PROMOTE if they reported using other body-based therapies including additional OMT, massage, physical therapy, or chiropractic therapy during the study. Obstetrics providers included physicians (medical doctors or doctors of osteopathy), certified nurse midwives, and women’s health nurse practitioners; all providers were blinded to study group assignment. Providers knew that their patient was participating in the study, but both subject and provider were asked to not discuss the study or treatments. Study subjects were compensated for their time and travel.
After consent was obtained, subjects were assigned randomly to 1 of 3 groups: OMT, placebo ultrasound treatment (PUT), or usual obstetric care only (UCO). A computer-generated randomization program was used to allocate women in blocks of 15, by clinic location, to each of the 3 treatment groups. At the first study visit, the research coordinator collected baseline data. Then the OMT specialist opened the randomization envelope to reveal the subject’s group assignment and provided the assigned treatment.
PROMOTE included 7 study visits that were scheduled to correspond with ongoing routine prenatal care at weeks 30, 32, 34, 36, 37, 38, and 39. Study visits occurred within 24 hours after routine prenatal appointments. The research coordinator scheduled each study appointment, confirmed medical clearance from the obstetrics provider, and collected data before treatment.
Both the OMT and PUT protocols addressed the same specific body regions that had been chosen for their relationship to common musculoskeletal changes in pregnancy that included bilateral cervical, thoracic, and lumbar paraspinal musculature; thoracolumbar junction; sacroiliac joint; hip, and anterior pelvis. Both OMT and PUT treatments were applied over clothing. OMT consisted of approximately 20 minutes of treatment provided by a physician board-eligible or certified by the American Osteopathic Board of Neuromusculoskeletal Medicine and trained in the PROMOTE protocol ( Table 1 ). Each OMT technique was performed on every subject for 1-2 minutes until an adequate tissue response was felt.
| Technique | Description |
|---|---|
| Seated thoracic articulation | • Patient’s arms rest on physician’s chest; physician reaches around patient to contact the articular pillars, then the rib heads. |
| • Thorax is extended and side bent/rotated as necessary for articulation. | |
| Cervical soft tissue | • Apply kneading, traction, inhibition, and/or stretching to cervical muscles. |
| Occipito-atlantal decompression | • Contact is near the occipital condyles with sustained anterior, lateral, and cephalad tension. |
| Thoracic inlet myofascial release | • Contacting the clavicles, upper thoracic spine, and ribs, the fascia is assessed in rotation, side-bending, and forward/backward bending motions. |
| • Tissues are positioned either directly or indirectly and held until released. | |
| Lateral recumbent scapulothoracic soft tissue | • With positioning to isolate the scapula, kneading, traction, and/or stretching are applied rhythmically to the musculature medial to the scapula. |
| • Positioning is altered to contact the posterior axillary fold, with kneading, inhibition, and stretching are applied rhythmically. | |
| Lateral recumbent lumbar soft tissue | • Kneading, lateral, rotational, and longitudinal stretching are applied in a rhythmic motion to the lumbar paraspinal musculature. |
| Abdominal diaphragm myofascial release | • With a lateral contact over the lower ribs, the motion of the diaphragm is assessed in rotation, side-bending, and forward/backward bending motions. |
| • Tissues are taken either directly or indirectly and held until released. | |
| Pelvic diaphragm myofascial release | • With anterior contact just superior to the pubic symphysis and posterior contact at the level of the coccyx and ischial tuberosities, the motion of the pelvic diaphragm is assessed in rotation, side-bending, and forward/backward bending motions. |
| • Tissues are taken in either a direct or indirect position until released. | |
| Sacroiliac articulation | • Hip and knee are flexed, with the leg supported. |
| • Compression is applied through the knee to engage the femur into the acetabulum. | |
| • The leg is rotated internally and circumducted then externally rotated and circumducted several times, while maintaining compression | |
| Pubic symphysis decompression | • Patient is in a supine position with the physician at the side of the patient. |
| • Hips and knees are flexed, with feet together on the table. | |
| • Muscle energy is applied, first with the knees pulled apart against resistance then being pulled together against resistance. | |
| Frog-leg sacral release | • Hips and knees are flexed, with feet together on table. |
| • Physician’s contact is cupping the sacrum with fingers at the base. | |
| • Sacrum is held at a balance point as the legs are externally rotated. | |
| • Inferior traction is applied while maintaining balance, and legs are straightened with the heels sliding down the table. | |
| Compression of the fourth ventricle (CV4) | • Contact medial to the occipital-mastoid suture with thenar eminences |
| • Encourage the occipital motion in extension phase, while resisting flexion until a still point is reached. | |
| • Allow the cranial rhythmic impulse to return to normal before disengaging. |
The PUT provided tactile and manual stimulation over the same regions as OMT. The ultrasound wand was applied with a circular, steady contact for approximately 2 minutes to each of the specified areas, which resulted in treatment duration similar to OMT. Although the ultrasound machine provided credible cues, such as a ticking timer or digital display, the machines were set to not emit any ultrasound waves.
The UCO group completed study questionnaires but received no study interventions nor additional time or interaction with the treating physician.
There were 2 primary outcomes for PROMOTE: pain and back-related functioning. LBP was measured with the Quadruple Visual Analog Scale, a self-reported reliable measure of 4 aspects of pain (now, average, worst, and best ) , that was used to calculate characteristic pain intensity (CPI). The CPI is a composite score reported on a scale of 0 to 100; higher values indicate higher pain. Back-related functioning was measured with the Roland-Morris Low Back Pain and Disability Questionnaire, a validated 24-item self-reported questionnaire for which higher scores indicate greater functional disability and sensitivity to change over time. Labor and delivery records provided information for secondary outcomes. After delivery, the research coordinator collected data from the subject’s medical records. All data were collected in paper form and transferred to an electronic dataset with the use of double data entry. Subjects completed the Short Form 12 version 2 Health Survey at the beginning of the study to estimate general health at baseline. Collected demographic information included race, ethnicity, age, weight, height, and parity.
Sample size calculations for primary outcomes indicated a sample size of 71 per treatment group would be needed to detect a 30% change in pain outcomes; however, this was less restrictive than the sample size required for the planned secondary outcome of meconium staining. Thus, calculations based on the secondary outcome were used for final sample size estimates. A sample size of 110 subjects per treatment group was estimated for 80% power at a 5% significance level ( P < .05) to detect a 62% reduction in the incidence of meconium staining. The incidence and percent reduction estimate was based on a retrospective case-control study finding of a lower incidence of meconium staining in women who received OMT compared with a control group. To allow for study attrition, the target recruitment goal was 400 subjects.
Data management and analyses were performed with the statistical software package IBM SPSS (version 19.0; IBM Corp, Armonk, NY). Demographic characteristics were described by frequencies and percentages for categoric data and by means and standard deviations for continuous data. Between-group comparisons were computed with the chi-square test for categoric data and analysis of variance for continuous data. Primary outcomes were analyzed with the use of a linear mixed model that was suitable for repeated measures with fixed effects for treatment group and treatment visit, which included an interaction term for treatment group and visit. For each of these variables, change from baseline was calculated and used as the data point for that visit. To address differences in baseline pain and disability, which might influence rates of change, models were adjusted for baseline values. Post-hoc analyses with Bonferroni adjustment were used to elucidate pairwise differences between treatment groups when main effects were detected. The linear mixed model analysis allowed for the use of all available data without censoring or imputation. Analysis was first performed with an intention-to-treat approach. An additional per-protocol analysis was performed on subjects who completed all 7 treatment visits. Finally, logistic regression was used for analysis of the secondary outcome of meconium staining.
Results
In PROMOTE, a total of 400 subjects were enrolled and assigned randomly to groups. As shown in Figure 1 , there were 136 women (34%) assigned to OMT, 131 women (33%) assigned to PUT, and 133 women (33%) assigned to UCO. Of these 400 women, 99 women (25%) completed all 7 treatment visits and were considered to have completed the protocol.
Baseline characteristics were similar across groups with the exception of body mass index (BMI; Table 2 ). The OMT group had a lower mean prepregnancy BMI than the other 2 groups. Table 3 shows that baseline pain and functioning were similar among the 3 groups; except on pain subscales at baseline, the OMT group reported higher levels of “pain now” than the PUT group and higher levels of “pain at best” than the UCO group.
| Variable | Osteopathic manipulative treatment (n = 136) | Placebo ultrasound treatment (n = 131) | Usual care only (n = 133) | P value |
|---|---|---|---|---|
| Age, y a | 23.99 ± 4.13 | 24.11 ± 4.10 | 24.70 ± 4.54 | .351 |
| Marital status, n (%) | ||||
| Single | 62 (45.6) | 64 (48.9) | 58 (43.6) | .712 |
| Married | 65 (47.8) | 61 (46.6) | 70 (52.6) | |
| Divorced or separated | 9 (6.6) | 6 (4.6) | 5 (3.8) | |
| Race/ethnicity, n (%) | ||||
| White | 32 (23.5) | 36 (27.5) | 31 (23.5) | .972 |
| Black | 25 (18.4) | 23 (17.6) | 22 (16.7) | |
| Hispanic | 76 (55.9) | 69 (52.7) | 77 (58.3) | |
| Other | 3 (2.2) | 3 (2.3) | 2 (1.5) | |
| Education level, n (%) | ||||
| Grade school | 11 (8.2) | 11 (8.4) | 8 (6.1) | .761 |
| High school | 75 (56.0) | 69 (52.7) | 67 (50.8) | |
| Some college and above | 48 (35.8) | 51 (38.9) | 57 (43.2) | |
| SF-12v2 Health Survey score a | 37.43 ± 7.22 | 38.96 ± 7.30 | 38.74 ± 7.08 | .185 |
| Baseline body mass index, kg/m 2 a , b | 25.51 ± 4.56 | 27.50 ± 6.44 | 27.54 ± 6.61 | .028 |
| Weight gain, kg a , b | 14.57 ± 6.48 | 15.14 ± 6.63 | 13.40 ± 7.27 | .211 |
| Nulliparous, n (%) | 41 (34.2) | 37 (35.6) | 32 (29.9) | .658 |
a Data are given as mean ± standard deviation
| Variable | Osteopathic manipulative treatment (n = 136) | Placebo ultrasound treatment (n = 131) | Usual care only (n = 133) | P value |
|---|---|---|---|---|
| Roland Morris Disability Questionnaire a | 6.70 ± 4.97 | 5.90 ± 4.68 | 6.55 ± 5.09 | .375 |
| Characteristic Pain Intensity b | 53.38 ± 20.33 | 48.53 ± 20.13 | 49.21 ± 19.82 | .103 |
| Pain now | 3.49 ± 2.54 | 2.75 ± 2.42 c | 2.93 ± 2.21 | .030 |
| Pain average | 5.07 ± 2.39 | 4.71 ± 2.34 | 4.78 ± 2.41 | .430 |
| Pain best | 2.49 ± 2.04 | 2.02 ± 1.80 | 1.65 ± 1.92 c | .002 |
| Pain worst | 7.46 ± 2.36 | 7.12 ± 2.32 | 7.08 ± 2.17 | .334 |
a The summary score (range between 0–24) is the unit of measure of the Roland Morris instrument ( http://www.rmdq.org )
b Score based on the visual analog scales, and does not have a unit of measure
Analysis of primary outcomes used an intention-to-treat model to examine changes in pain and back-related functioning for each group across the study (n = 400). The intention-to-treat analysis included all randomly assigned subjects, regardless of the number of visits completed. These findings indicated significant treatment effects for both pain as assessed by CPI and back-related functioning as assessed by Roland-Morris Low Back Pain and Disability Questionnaire ( P < .001 for both). Specifically, OMT was effective for mitigating the progression of pain and deterioration of back-related functioning compared with the UCO group.
For each of the outcomes, the OMT group either demonstrated improvement or remained stable across time ( Figure 2 ). In contrast, the UCO group experienced worsening pain and functioning. Although there was an effect of treatment and OMT was different from UCO, it is important to note that OMT outcomes did not differ significantly from those of the PUT group ( Table 4 ). The addition of baseline BMI, maternal age, and parity adjustments into the model yielded findings that were consistent with the nonadjusted analysis.
