INVOLUNTARY ACTIVITY OF PELVIC FLOOR MUSCLES IN HEALTHY WOMEN WHILE PERFORMING ACTIVITIES OF DAILY LIVING

Schraknepper A1, Wassmer Saeuberli P2,3, Eichelberger P1, Luginbuehl H1, Radlinger L11Bern University of Applied Sciences, Department of Health Professions, Bern, Switzerland, 2Zurich University of Applied Sciences, School of Health Professions, Institute of Physiotherapie, Winterthur, Switzerland, 3Cantonal Hospital Baden AG, Section Physiotherapy, Baden, SwitzerlandBackground: Activities of daily living (ADL) accompanied by increasing intra-abdominal pressure can provoke urine loss in women with stress urinary incontinence (SUI). The affected can therefore complain involuntary loss of urine associated with change of body position. For preventing SUI, involuntary pelvic floor muscle (PFM) activity is important.Purpose: The aim of the current study was to investigate a) whether there is PFM activity, i.e. involuntary response, in healthy nulliparous women during moderate ADL such as using stairs, rising from a chair and lifting of loads, and, b) whether there is a difference in PFM activity between three different speeds of stair using, two different speeds of chair rising and the lifting of two different loads.Methods: This was an exploratory, cross-sectional study investigating PFM activity during ADL, namely during three different speeds (slow, medium, fast) of stair use, up and down, two different speeds of chair rise (slow, fast) and lifting of two different loads (10 kg, 15 kg). PFM electromyographic (EMG) activity of 16 healthy nulliparous women was determined using vaginal probes while they lifted loads, went up and down stairs and rose from a chair, with different weights and speeds, respectively. EMG signal root mean square values were analyzed before and after onset of load. EMG values were normalized to peak activity during maximum voluntary contractions (%MVC). PFM activity-onset threshold was determined as the mean of rest activity plus two standard deviations (SD). PFM activities were analyzed by ANOVA for repeated measures between before and after onset of load and the three different speeds (slow, medium, fast) followed by adequate post hoc t-tests. Additionally, t-test between the different speeds (slow, fast) and different loads (10 kg, 15 kg) for paired samples was calculated. Level of significance: α = 0.05.Results: The 16 included participants had a mean (± SD) age of 26.8 (± 5.2) years and body mass index of 22.3 (± 2.4) kg/m2. The mean threshold of PFM activity onset was 32.4±12.4 %MVC. In all measured ADL, PFM activity was higher than during rest. Stair up and down showed long lasting PFM activity and activity tended to increase with higher speed (66.2 - 152.1 %MVC). Load lifting (159.1 - 194.1 %MVC) and chair rise (86.7 - 94.2 %MVC) also showed higher activity with increasing weight and speed, respectively.Conclusion(s): Electromyographic measurements showed involuntary PFM activity in healthy nulliparous women in ADL, namely during stair use, chair rise and load lifting. The increase of involuntary PFM activity with speed and ground reaction force during stair use and chair rise is comparable to findings during other whole-body impact activities (running, mini-trampolining, drop-landings).Implications: The investigated ADL can presumably be applied to provoke involuntary PFM activity in healthy nulliparous women. However, future studies should clarify if or how ADL could be helpful as training tasks in preventing or treating SUI. Further research on involuntary PFM activity in women who suffer from SUI is needed to differentiate possible pathological changes of the involuntary PFM activity and to improve training concepts with focus on involuntary PFM activity.Keywords: Electromyography, pelvic floor, stress urinary incontinenceFunding acknowledgements: This work was unfunded.Topic: Women's & men's pelvic health; Human movement analysis; MusculoskeletalEthics approval required: YesInstitution: Bern University of Applied Sciences, Department of Health ProfessionsEthics committee: Ethics Committee of the Canton of Bern, SwitzerlandEthics number: Study ID: 2016-00786All authors, affiliations and abstracts have been published as submitted.