Takahashi Y1, Kitta T1, Ouchi M2, Kumamoto T3, Seko T3, Moriya K1, Shinohara N1
1Hokkaido University, Graduate School of Medicine, Department of Renal and Genitourinary Surgery, Sapporo, Japan, 2Health Sciences University of Hokkaido, School of Rehabilitation Sciences, Tobetsu, Japan, 3Hokkaido Chitose College of Rehabilitation, Department of Rehabilitation, Faculty of Health Sciences, Chitose, Japan
Background: The symptoms of stress urinary incontinence (SUI) are involuntary leakage from the urethra with physical exertion, sneeze or a cough. Stress leakage is presumed to be due to increased abdominal pressure and anti-pressure. Declining pelvic floor muscle (PFM) strength is one of the factors of SUI. The PFM do not work in isolation but work in synergy with the abdominal muscles. The previous studies reported that continent subjects, co-contraction muscles such as Multifidus muscle (MF), abdominal Internal oblique muscles (IO) co-contract with the PFM at supine and standing position. However, few studies have focused on PFM co-contraction muscles in the half sitting position.
Purpose: The purpose of this study was to investigate the relationship between vaginal pressure (VP) and trunk muscle activity during PFM contraction in the half sitting position.
Methods: The subjects were 18 healthy women (median: age 25.0 years, height 161.0 cm, weight 52.0 kg, BMI 20.0 kg/m2). The measurements were performed in the half sitting position with the knees flexed to approximately 45°. As an index of PFM strength, we measured vaginal pressure at rest and maximum voluntary contraction of PFM for 5 seconds, and the using by the vaginal pressure instrument (MizCureTM, OWOMED, Korea). At the same time, resting and functional bioelectric activity of MF, IO, external oblique muscle (EO), and lower rectus muscle (LRA) were measured with a surface electromyographic (Tele Myo G2, Noraxon, USA). Muscle activity level was calculated as normalized % integrated EMG (%IEMG) of the values maximal vaginal pressure during PFM contraction. We compared the VP of rest and PFM contraction using a paired t-test. Also, two-way analysis of variance with repeated measures was employed to compare the tasks (rest, PFM contraction) and four different muscles (MF, IO, EO, LRA) as variable factors. Statistical significance was set at 5%.
Results: The VP values during PFM contraction was higher than those of at rest (p 0.000). %IEMG showed interaction effects between factors of tasks and four different muscles (p = 0.0016). As a result of multiple comparison test, at all muscles, ％IEMG during PFM contraction was increased higher than at rest (p = 0.0001). ％IEMG during PFM contraction showed significantly higher in IO than MF(p = 0.0159), EO(p = 0.0015), and LRA (p = 0.0003). MF was significantly higher than EO (p = 0.0494) and LRA (p 0.0000). Also, EO was significantly higher than LRA (p = 0.0024). %IEMG at rest showed significantly higher in IO than EO (p = 0.0023) and LRA (ｐ= 0.0002), as well as MF than EO (p = 0.0001) and LRA (p 0.0000). Also, EO was significantly higher than LRA (p = 0.0003).
Conclusion(s): This is the first study to revealed that four trunk muscles co-contracted with PFM in the half sitting position. It was suggested that IO is the highest activity during PFM contraction and is involved as co-contraction muscle to increase vaginal pressure.
Implications: IO training could be facilitated PFM contraction and contribute to continent mechanism for SUI.
Keywords: half sitting position, PFM, trunk muscle activity
Funding acknowledgements: This research was supported by grants from the Japanese Physical Therapy Association (H28-B16).
Purpose: The purpose of this study was to investigate the relationship between vaginal pressure (VP) and trunk muscle activity during PFM contraction in the half sitting position.
Methods: The subjects were 18 healthy women (median: age 25.0 years, height 161.0 cm, weight 52.0 kg, BMI 20.0 kg/m2). The measurements were performed in the half sitting position with the knees flexed to approximately 45°. As an index of PFM strength, we measured vaginal pressure at rest and maximum voluntary contraction of PFM for 5 seconds, and the using by the vaginal pressure instrument (MizCureTM, OWOMED, Korea). At the same time, resting and functional bioelectric activity of MF, IO, external oblique muscle (EO), and lower rectus muscle (LRA) were measured with a surface electromyographic (Tele Myo G2, Noraxon, USA). Muscle activity level was calculated as normalized % integrated EMG (%IEMG) of the values maximal vaginal pressure during PFM contraction. We compared the VP of rest and PFM contraction using a paired t-test. Also, two-way analysis of variance with repeated measures was employed to compare the tasks (rest, PFM contraction) and four different muscles (MF, IO, EO, LRA) as variable factors. Statistical significance was set at 5%.
Results: The VP values during PFM contraction was higher than those of at rest (p 0.000). %IEMG showed interaction effects between factors of tasks and four different muscles (p = 0.0016). As a result of multiple comparison test, at all muscles, ％IEMG during PFM contraction was increased higher than at rest (p = 0.0001). ％IEMG during PFM contraction showed significantly higher in IO than MF(p = 0.0159), EO(p = 0.0015), and LRA (p = 0.0003). MF was significantly higher than EO (p = 0.0494) and LRA (p 0.0000). Also, EO was significantly higher than LRA (p = 0.0024). %IEMG at rest showed significantly higher in IO than EO (p = 0.0023) and LRA (ｐ= 0.0002), as well as MF than EO (p = 0.0001) and LRA (p 0.0000). Also, EO was significantly higher than LRA (p = 0.0003).
Conclusion(s): This is the first study to revealed that four trunk muscles co-contracted with PFM in the half sitting position. It was suggested that IO is the highest activity during PFM contraction and is involved as co-contraction muscle to increase vaginal pressure.
Implications: IO training could be facilitated PFM contraction and contribute to continent mechanism for SUI.
Keywords: half sitting position, PFM, trunk muscle activity
Funding acknowledgements: This research was supported by grants from the Japanese Physical Therapy Association (H28-B16).
Topic: Women's & men's pelvic health; Musculoskeletal
Ethics approval required: Yes
Institution: Hokkaido Chitose College of Rehabilitation
Ethics committee: ethical review board of Hokkaido Chitose College of Rehabilitation
Ethics number: 2017-01
All authors, affiliations and abstracts have been published as submitted.
