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B. Arranz-Martín1, M. Torres-Lacomba1, B. Navarro-Brazález1, V. Prieto-Gómez1, B. Sánchez-Sánchez1
1Universidad de Alcalá, Physiotherapy, Alcalá de Henares, Spain
Background: Pregnancy and childbirth involve different morphophysiological modifications, especially affecting the abdominal and pelvic floor muscle structures. Abdominal distention, weight gain on pelvic organs, and perineal injuries associated with vaginal delivery are considered risk factors for the development of abdominopelvic cavity dysfunctions. Evidence on the synergistic activation of pelvic floor muscles and abdominal muscles is found, however, it is not known whether this synergy is maintained after pregnancy and childbirth, nor the functional effects of this synergistic activation on the displacement of the PFM. Considering the connections of the abdominopelvic cavity, the therapeutic approach includes exercises for PFM and TrA contraction and progressively exercises of the abdominal wall. However, the change of the different abdominal muscles and the PFM in these exercises during and after the first year postpartum is not known.
Purpose: To describe the differences in muscle thickness and neuromuscular activity of the abdominal muscles during a semi curl-up, an ADIM and a PFMC in primiparous women during the first 18 months postpartum compared with nulliparous and nulligest women. Secondary objectives were to describe the synergistic activation of the PFM and TrA during the semi curl-up and ADIM in terms of PFM displacement, and to determine the correlation between IRD and ultrasound and electromyographic ratio of change of RA and TrA, and between IRD and the symptoms and impact of pelvic floor dysfunction in primiparous compared to nulliparous women.
Methods: Abdominal muscles and pelvic floor muscles (PFM) activation were measured using B-mode and M-mode ultrasound imaging and surface electromyography in a supine position. Abdominal thickness, PFM displacement and neuromuscular activity of both abdominal and PFM were assessed at rest and during a semi curl-up, an abdominal draw-in maneuver, and a PFM contraction. Postpartum women performed four assessment at 6-8 weeks (A0), 3-4 months (A1), 10-12 months (A2) and 16-18 months (A3) after childbirth. In the nulliparous group a single visit was carried out.
Results: At the A0 and A1 assessment primiparous showed a lower ratio of TrA contraction during ADIM and semi curl-up than nulliparous (p <0.05). In medium (A2) and long term (A3) primiparous showed lower ratio of RA contraction in ADIM (p < 0.05) and PFM contraction (p < 0.05 ) with respect to A0. Primiparous showed lower RA (p = 0.001) and deep abdominal muscle (p = 0.050) electromyographic activation ratios during semi curl-up in A0 and lower deep abdominal muscles activity in ADIM in all assessments compared to nulliparous (p < 0.05).
Conclusion(s): Postpartum women show differences in abdominal muscle thickness and neuromuscular activity during semi curl-up, pelvic floor muscle contraction and specially during ADIM compared to nulliparous.
Implications: Further research on the alterations in abdominopelvic muscle activation will allow the adaptation of therapeutic programs aimed at improving abdominal function, without negative effects on PFM. In these terms, the caudal displacement of the PFM described during abdominal maneuvers makes it necessary to monitor and train the integration of the voluntary contraction of the PFM when faced with abdominal maneuvers that increase intra-abdominal pressure.
Funding, acknowledgements: This study was part of the research project supported by a predoctoral grant at the Universidad de Alcalá (Madrid, Spain).
Keywords: abdominal muscles, postpartum period, pelvic floor
Topic: Musculoskeletal: spine
Did this work require ethics approval? Yes
Institution: Hospital Universitario Príncipe de Asturias
Committee: Comité de Ética de la Investigación
Ethics number: OE 23/2018
All authors, affiliations and abstracts have been published as submitted.
