RESUMEN
INTRODUCTION: Pelvic girdle pain (PGP) is the most common musculoskeletal concern in pregnancy. The Active Straight Leg Raise (ASLR) test is diagnostic. Sacroiliac joint (SIJ) belts are included in multimodal therapy, but there is no established predictive measure to determine which pregnant women will benefit. OBJECTIVE: To determine if the ASLR score is immediately reduced by SIJ belt application and whether PGP pain and function improves after 4 weeks of belt use. DESIGN: Prospective observational cohort study. SETTING: Academic medical center. PARTICIPANTS: Pregnant women at least 18 years of age in the second or third trimester of pregnancy with posterior PGP and ASLR score of 2 to 10. INTERVENTIONS: Four-week SIJ belt use. MAIN OUTCOME MEASURES: ASLR, Numerical Rating Scale (NRS), Pelvic Girdle Questionnaire (PGQ), Perceived Global Impression of Improvement (PGII). RESULTS: Sixty-three women enrolled. On multivariable analysis, immediate belted ASLR score was -2.70 points lower than the non-belted ASLR score (P < .001). Four weeks later there was significant improvement in the ASLR score with a belt (Mdiff = -0.99; P = .001) and without a belt (Mdiff = -1.94; P < .001); the decline was more precipitous for the non-belted response (Mdiff = -0.96; P = .02). Current NRS pain scores declined from baseline by approximately -0.94 points (P < .001). This decline did not depend on ASLR scores (interaction P = .43) or wearing a belt at the time of testing (interaction P = .51). Similar conclusions held for participants' usual NRS score and average PGQ score. After 4 weeks, 82% reported improvement based on the PGII. CONCLUSIONS: SIJ belts are a safe, well-tolerated, and effective therapeutic option for pregnancy-related PGP. The ASLR score is immediately reduced following SIJ belt application but does not predict pain score 4 weeks later. SIJ belt leads to significant improvements in pain and function over time.