Proof of concept: differential effects of Valsalva and straining maneuvers on the pelvic floor

Talasz H, Kremser C, Kofler M, Kalchschmid E, Lechleitner M, Rudisch A:  Eur J Obstet Gynec and Repord Biology 164(2012) 227-233

Ann Dunbar PT, DPT, MS, WCS

April 9, 2014

Introduction: History of Valsalva Maneuver (VM): 

• Named after physician (Antonio Maria Valsalva 1666-1723) whose main interest was in studying the ear. He described use of forceful inflation of air from the oro-nasopharyngeal cavity into Eustachian tubes and then into middle ear with closed mouth and nostrils. Over time, VM became widely used  in medicine including otorhinology, internal medicine (see article for details), and OB/GYN (to assess urinary incontinence, pelvic organ prolapse, to aid diagnosis of intrinsic sphincter deficiency in urodynamic testing, to demonstrate maximum impact of IAP on pelvic organ descent.
• More recently, an article published in 2006, reported on current understanding of VM which demonstrated variance from its original definition thus presenting confusion between 2 different maneuvers.

Primary Aim:  “to prove a basic physiological principle in healthy women, demonstrating different movement patterns of the diaphragm, pelvic floor (PF), and muscular wall surrounding the abdominal cavity during a Valsalva maneuver (VM) as opposed to a straining maneuver (SM) by means of real-time dynamic MRI.”

Study Design:  Descriptive

Methods:

Definitions:

(1)    the VM: relaxing diaphragm and abdominal contents are forced cranially by increasing intra-abdominal pressure (IAP) increasing and directing this increased pressure toward nasopharynx and glottis.

(2)    The SM: abdomino-pelvic contents forced caudally by increased IAP against a relaxing PF to support delivery or defecation.

Subjects: 4 women (2 nulliparous and 2 perimenopausal, one of whom was nulliparous)  See Table 1.

Pelvic Floor Assessment:  according to International Continence Society using PERFECT.

Subjects had participated in previous research and knew about PF and role of diaphragmatic breathing;

Instructions for VM and SM utilized everyday activities for clarity. No instruction to contract/relax PFM was given.  Subject #2 knew about difference between SM and VM.

Dynamic MRI

Study completed in supine position. After MRI localized, subjects did 3 tasks (forceful breathing, VM, SM: see article for details) with 3 minutes rest between efforts.  Sequence took 11 seconds and was repeated 12 times.

Analysis of MRI (See Figure 1)

Coronal Plane: used cranio-caudal displacement of ventral dome (cupolae) of diaphragm in reference to a line transecting L4/5.

Mid-Sagittal Plane: Pubococcygeal line (PCL) and M-line defined level of muscular PF; Used displacements of puborectalis m. along M-line to evaluate PF elevation or descent.

Axial Plane: Anterolateral abdominal m thickness and transverse horizontal abdominal diameter were measured at umbilical level.

Measures of Muscle Function:

• Diaphragmatic Concentric:  used maximum inferior diaphragmatic position during VM, SM and forceful breathing; this served at the starting point for inspiration.
• Diaphragmatic Eccentric:  considered to be reflected by cranial movement of diaphragmatic  dome during expiration or diaphragmatic displacement from high IAP.
• PFM Concentric: considered to be reflected by puborectalis elevation along M-line.
• PFM Eccentric: considered to be reflected by descent of the puborectalis.
• Abdominal Concentric:  considered to be reflected by increase in abdominal m thickness.
• Abdominal Eccentric:  considered to be reflected by a decrease in abdominal m thickness.

Results:

	Inspiration	Expiration	VM**	SM**
Diaphragm	Moves caudally	Moves cranially	Moved cranially	Remained mostly in position of inspiration
PFM	Moves caudally	Moves cranially	Moved cranially	Moved caudally
Anterolateral Abdominal  Thickness	Thickness decreased	Thickness increased	Thickness increased	Thickness increased
Transverse Abdom Diameter	Increased at umbilical level	Decreased at umbilical level	Decreased	Decreased

**Authors report that both the VM and SM began with inspiration, caudal movement of the PF and diaphragm, decreased abdominal m thickness, and increased transverse abdominal diameter

 

Discussion/Comments

• This study demonstrates that SM and VM are different tasks with dissimilar respiratory patterns and subsequent variations in performance of PF and diaphragm.
• For both SM and VM, IAP rises with contraction of abdominal mm, spreading caudally during SM toward a relaxing PF and spreading cranially during VM toward a relaxing diaphragm.

Respiratory Phase	Diaphragm Action	PF Action	Abdominal Action
Inspiration	Phasic concentric contraction of diaphragm leads to flattening of diaphragm and caudal movement toward abdominal cavity	Concomitant eccentric  activity of abs and PF facilitates caudal movement of diaphragm leading to downward movement of organs and PF; Eccentric activity develops tension to initiate automatic concentric contraction in subsequent expiratory phase	Concominant eccentric activity of abs and PF facilitates caudal movement of diaphragm leading to downward movement of organs and anterior bulging of abdom wall; Eccentric activity develops tension to initiate automatic concentric contraction in subsequent expiratory phase
Expiration	Diaphragm  acts eccentrically and is displaced cranially	Concomitant contraction  of PF and abs lead to increased IAP and cranial displacement of organs	Concomitant contraction of Abs and PF leads to diminution of abdom cavity, increased IAP and cranial displacement of organs

 

• VM is an expiratory pattern, not as much cranial movement of diaphragm as with forced expiration, but underlying mechanisms are same.
• Authors considered reduction in transverse abdominal diameter and increase in anterolateral abdominal m. thickness to indicate simultaneous contraction of transv abdominis, internal and external obliques during VM.
• Co-contraction of PFM with abdominals elevates the PF, compresses the urethra, supports continence, and the anatomical position of abdominal organs against rises in IAP.
• In contrast to a common practice, VM actually protects the PF against high IAP and is not appropriate for provoking pelvic organ descent or urine leakage.
• Additionally, authors discuss SM as beginning with deep inspiration, flattening the diaphragm into abdom. cavity, downward displacement of organs against eccentrically contracted PF and abdominal mm. so abdominal wall bulges anteriorly and PFM descends.  With intention to defecate, closed glottis will help to maintain intra-thoracic volume.  Abdominal wall mm then contract to increase IAP and because of contracted diaphragmatic mm and intra-thoracic pressure, the pressure spreads caudally toward the relaxed PF.  Then have more pelvic organ descent plus urine or stool evacuation.
• Authors consider anterolateral abdominal muscles
• Well known that there is coordinated synergy between predominantly deeper abdominal mm, PFM and diaphragm with breathing while maintaining posture and trunk stability (local muscle system)
• Superficial abdominal mm (mostly Ext Obl) support deep abdominal mm to support IAP when maximum effort is required
• Authors note that during SM however, these mm seem to act differently.  At end of inspiration, deep abdominal mm and PFM remain in the lengthened position (eccentric), diaphragm remains in flattened position (concentric) while superficial abdominals (mostly EO) begins to contract isometrically to increase IAP.
• Authors considered IAP to be distributed equally in all directions (Pascal’s principle) however the pressure will cause bulging predominantly to those parts of the abdominal [and pelvic] boundaries whose muscles are not concentrically contracted at the time of the increase in IAP. This would be the diaphragm during VM and the PF and inferior abdominal wall with SM.
• Conclusion: VM protects the contracted and elevated PF against high increases in IAP and not appropriate method for provoking pelvic organ descent or urine leaking.

Limitations

• Small sample and subjects familiar with PF and coordination with breathing so not reflective of the general population.
• Measurements of TA diameter and total thickness of anterolateral abdom mm at one level (umbilicus) does not allow for contributions of other abdominal muscles during VM or SM.
• Investigations conducted in supine position which affects level of diaphragm and respiratory movements; may also affect PFM movements (eg, it is known that vaginal resting pressure is lower in supine).
• MRI did not allow for changes in intra-abdominal pressure which would be helpful to measure.
• Authors recommend for future studies, additional MRI studies in conjunction with EMG and pressure recordings.

Clinical Application

• Do these findings suggest any changes for you in you practice?
• How are these findings applicable for patients with constipation?   Stress urinary incontinence?
• Breathing requires eccentric activity of abdominal and PFMs.  How would a short or overactive  pelvic floor influence this? Have you seen any patients with overactive PFMs who also have dysfunctional breathing patterns?