Exploring the Effects of Standardized Soft Tissue Mobilization on the Viscoelastic Properties, Pressure Pain Thresholds, and Tactile Pressure Thresholds of the Cesarean Section Scar

Background: Objectives of soft tissue mobilization applied to cesarean section (C-section) scars are to decrease stiffness and to reduce pain. Research investigating these effects is lacking. Materials and methods: The authors conducted a descriptive, exploratory, proof-of-concept clinical study. Women aged 18 to 40 years who had undergone at least one C-section were recruited. A trained osteopath performed standardized mobilization of the C-section scar once a week for 2 weeks. Scar quality and pain characteristics, viscoelastic properties, pressure pain thresholds, and tactile pressure thresholds were measured before and after each session. Paired Student's t-tests and Friedman's test with Dunn-Bonferroni adjustment were performed to assess the immediate and short-term effects of mobilizations. Kendall's W and Cohen's d were calculated to determine effect sizes over the short term. Simple bootstrapped bias-corrected and accelerated 95% median confidence intervals were computed. Results: Thirty-two participants completed the study. The Patient and Observer Scar Assessment Scale questionnaire revealed differences with small and moderate effects for stiffness (p = 0.021, d = 0.43), relief (p < 0.001, d = 0.28), surface area (p = 0.040, d = 0.36), flexibility (p = 0.007, d = 0.52), and participant opinion (p = 0.001, d = 0.62). Mobilizations increased elasticity (p < 0.001, W = 0.11), decreased stiffness (p < 0.001, W = 0.30), and improved pressure pain thresholds (p < 0.001, W = 0.10) of the C-section, with small to moderate effects. The results also showed decreased tone and mechanical stress relaxation time, as well as increased tactile pressure thresholds at the different measurement times (p < 0.05), but trivial effect sizes (W < 0.10). Creep showed trivial effect and no significant difference (p = 0.09). Conclusion: This study showed that two sessions of mobilization of C-section scar might have a beneficial effect on some viscoelastic properties of the C-section as well as on pain. Some variables of interest useful for future empirical studies are highlighted. ClinicalTrial. Gov NCT04320355.