Efficacy of Lumbar Support on Pain, Disability, and Motor Control in Women with Postpartum Pelvic Girdle Pain: a Three-armed Randomized Controlled Trial    

Abstract Background Pregnancy-related posterior pelvic girdle pain (PPGP) is a common cause of back pain and disability in the postpartum period. The objective of this study was to investigate the efficacy of orthotic support on pain, disability, and motor control in women with pregnancy-related PPGP. Methods Eighty-four women with a clinical diagnosis of pregnancy-related PPGP participated in this randomized controlled trial (RCT). Participants were randomly allocated into three groups (with a ratio of 1:1:1): the pelvic support group, the lumbar support group, and the control group (patient-education leaflet). Pain severity, disability, effort during the active straight leg raising test (ASLR), maximum isometric muscle force (hip flexion and trunk rotation), and joint position reproduction (JPR) of hip abduction were assessed as study outcomes. These variables were measured at four time points—before the intervention, immediately after the intervention, at the 4-week follow-up (at this time, the intervention period was terminated), and at the 5-week follow-up (one week after discontinuing the interventions)—to evaluate the possible effects of wearing support. Repeated-measures multivariate analysis of variance (MANOVA) was applied to determine the statistical significance between groups. Bonferroni post-hoc correction was used to identify significant differences between groups at different study time points. Results There was a significant interaction effect for group×time for the study outcomes, including pain severity, disability, effort during the ASLR, and maximum isometric muscle force between groups (p < 0.001), except JPR of hip abduction (p = 0.13). There were statistically significant differences in post hoc comparisons for pain intensity and effort during the ASLR in lumbar support versus control condition and for maximum isometric muscle force in orthotic interventions versus control conditions immediately after the intervention (P < 0.008). Post hoc tests demonstrated statistically significant differences in orthotic interventions versus control conditions after 4-week and 5-week follow-ups (P  0.008). Conclusions For women with pregnancy-related PPGP, both lumbar and pelvic supports were beneficial for decreasing pain and disability symptoms. Lumbar support showed better results for managing PPGP than pelvic support. Clinical Trial registration: Iranian Registry of Clinical Trials IRCT20150210021034N11. Date of registration: April 31, 2021. Available at: https://irct.behdasht.gov.ir/trial/70670