Introduction and hypothesis: Perineal preparation techniques for childbirth have been used with the aim of reducing perineal tears during the expulsive phase of labor. However, no studies were found to investigate the effects of instrument-assisted stretching versus perineal massage on pelvic floor muscle (PFM) variables. Therefore, the aim of this study was to evaluate the effect of instrument-assisted stretching versus perineal massage on the extensibility and strength of the PFMs.
Methods: Primiparous women were randomized to the instrument-assisted stretching (IStr) group (n = 13) and perineal massage (PnM) group (n = 14). The groups participated in eight sessions, twice weekly, beginning at the 34th gestational week. The IStr group underwent the intervention for 15 min using EPI-NO®. The PnM group underwent a perineal massage protocol for 10 min. Each woman was evaluated by a blinded physiotherapist before, after four and after eight sessions for primary (PFM extensibility using the EPI-NO® circumference) and secondary (PFM strength using a manometer) outcomes. Covariate analysis (ANCOVA) was used to compare the groups using the baseline values as a covariate.
Results: Both groups showed an increase in PFM extensibility compared with the evaluations before and after four and eight sessions (PnM group from 17.6 ± 1.8 to 20.2 ± 1.9 cm; IStr group from 19.9 ± 1.6 to 22.9 ± 1.6 cm;p < 0.001). There was no difference between groups. Regarding muscle strength, no statistical differences were observed between evaluations or between groups.
Conclusions: Instrument-assisted stretching and perineal massage increase extensibility and do not alter the strength of PFMs in pregnant women.
Keywords: Muscle-stretching exercises; Natural childbirth; Pelvic floor; Perineum; Physical therapy specialty.