No technical difficulties and a lot of good discussion this month. Thanks to all who contributed (10 callers). I think we all have more questions than answers. Check out the recordings and outlines below.
This month’s articles
Bendova P, Ruzicka P, Peterova V, Fricova M, Springrova I. MRI -based registration of pelvic alignment affected by altered pelvic floor muscle characteristics. Clinical Biomechanics 2007;22:980-987.
Sapsford et al. Pelvic floor muscle activity in different sitting postures in continent and incontinent women. Arch Phys Med Rehabil 2008;89:1741-1747.
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Pelvic floor muscle activity in different sitting postures in continent and incontinent women.
Sapsford RR, Richardson CA
Introduction
This was a follow up to a study documenting the occurrence of increased PFM activity in upright sitting in continent women. This study included incontinent women.
Ruth’s landmark study (Neurourol Urodynam 2001;-42) was sited – “a sense of decreased activation of the PFM in a flexed position”. And we know the neutral spine is the best position for TrA contraction.
Methods
Nine asymptomatic women, 8 women with self reported SUI . Asymptomatic women were slightly older, slightly more babies and slightly heavy all of which would bias them toward more PFM dysfunction.
EMG with Perform vaginal sensor (women sat on a seat with a cut out to decrease pressure on the sensor). Surface electrodes were also placed in 3 positions for the abdominal muscles. Instrumentation of the device is very good (band pass 20 to 1000Hz with sampling of 2KHz).
Researchers confirmed proper PFM contraction. It appears they recorded 10 seconds of PFM resting activity in 3 positions three different times – slumped supported, upright supported, and very tall unsupported (added later). 5 seconds of each trial was used. Data from three trails of each position was averaged. Because they were recording resting tone – normalization was not used as they felt it would impact reliability of data among the groups. (Normalization is a percent of the MVC which would be different among the groups).
Results
Comparison of slumped supportive to upright unsupportive – increased PFM and right internal oblique and TrA.
Secondary analysis did not support this difference between SUI and controls.
Secondary analysis did show significant increase in
- PFM .001
- L external oblique .003
- Left internal oblique and TrA .046
- Right external oblique .005
- Right internal oblique and TrA .002
- No change in rectus
Subjects with SUI had significantly less lordosis than controls.
Decreased lordosis = less PFM activity
Research on the association of lordosis with increased incidence of POP is contradictory with 2 papers sited in this study showing decreased lordosis related to increased POP with the theory that decreased lordosis = decreased PFM activity however there is a study by Slieker-ten Hove Int Urogynecol J (2010) 21:311–319 showing no difference in PFM activity in 2 groups with and without POP
Increased abdominal muscle activity in the upright posture = increased abdominal pressure = increased PFM activity - Probable link between posture and SUI .
This paper generated much discussion with several PTs stating they progress patients through the developmental sequence during treatment. It seems to make sense. But do outcomes change if upright sitting and normal abdominal muscle activity are included in the treatment protocol?
Bordello-France 2006 Phys Ther 86:974-986. Well done RCT comparing PFM training in supine only and supine with upright – no sig difference in multiple outcomes (PFM MMT, outcomes measures and sx). It is only one study but it does not support the idea that including upright changes outcomes.
Several relationships were pointed out
- Lumbar flexion = coccyx flexion = PFM on slack – possibly related to loss of support and sx
- Long term slouched sitting may contribute to a short PFM through the above mechanism. In this case it is painful and difficult to maintain upright sitting due to the pull of the short PFM on the sacrum and coccyx.
- The opposite was also discussed. You may have better success down training the PFM in supine trunk flexion as this seems to be a spinal position of lower PFM activity naturally
Also remember this study measured resting tone – how much does that impact symptoms and outcomes?
Bendova P, Ruzicka P, Peterova V, Fricova M, Springrova I. Clinical Biomechanics 2007;22:980-987.
Introduction
The introduction discusses several previous papers on the role of the PFM in sacral alignment. I did have a chance to look up a few of them.
· Pool-Goudzwaard 2004 – significant counternutation of the sacrum with simulated PFM contraction. This was embalmed humans with springs attached. They measured stiffness and movement. In females the “PFM” stiffened the SIJ 8.5% (no change in males). Posterior rotation of sacrum in both males and females.
· Tichy articles are about the glut max and a fetal muscle called the coccygeofemoralis muscle which fuses with the glut max during development.
· Schamberger is a book and I could not get the Malbohan or Snijders articles – would be great if someone could look these up.
· I was able to get a copy of a very complex article which created a computer model of forces and applied shear forces to the SIJ and then removed them.
- They found only activation of the tranversus abdominis and the PFM (coccygeus, iliococcygeus, pubococcygeus) improved SIJ stability. I think we all accept that the PFM can increase stiffness in the SIJ. I am intrigued with the statement that unilateral increases in tension “is claimed to generate force imbalance throughout the pelvic ring”. I suspect this but have not seen evidence in living humans.
· On another subjects the Handa article was interesting stating wider transverse inlet (odds ratio 3.425) and shorter obstetrical conjugate (sacral promontory to pubic bone) (odds ratio 0.233) were significantly associated with pelvic floor disorders – not PFM dysfunction but dx like UI and POP . So it really is your mother’s fault.
Method
This author used electrical stimulation
· 50 Hz, 300 usec, 3 seconds on and 6 seconds off for 5 minutes. By previous research this would be well suited for PFM contraction.
· The stimulation was delivered by surface electrode in the “paracoccygeal region”. In an attempt to “create a shortening contraction of the coccygeus, levator ani and caudal portion of the glut max pars coccygeofemoralis”.
· RED FLAG – page 984-985
- Distance between coccyx and ischiadica changed 2.65mm in test subjects and 2.44mm in controls
- Distance between cornu sacrale and trochanter changed 2.28mm in test subjects and 0.73mm in controls
- Yes I would agree they stimulated the caudal portion of the glut max but there is no evidence of PFM contraction
The authors then described a complex method of measuring landmark changes with MRI . Seems good to me – any input?
Results
· MRI method showed good reproducibility and ability to detect change especially in the cranio-caudel direction (not really the direction the SIJ was proposed to move).
· Test showed control group had variation / movement of structures 2.5 mm while test subject’s landmarks moved an average of 3.79 mm (with 33% of subjects have more than 4mm movement).
· Most movement occurred in right
- Femoral head – this would have to be the glut, I can not see in what direction this bone moved
- Innominate – B posterior rotation, can not picture the PFM moving the innominate
- Coccyx – moved to right, inferior and anterior. Makes sense here but could still be the caudal glut max
- Sacrum – apparently the sacrum did not move a lot? But they do site left oblique axis posterior rotation with lateral down slip, could this be PFM. I am not sure the glut max could move sacrum into lateral down slip
· Further stats did not show a significant variation between groups
Discussion
Sacral movement
· Ticky article (about glut contraction) is sited as creating backward sacral torsion around a left oblique axis.
· In contrast Schamberger’s “theory” notes forward torsion around the left oblique axis.
· Seems right PFM would pull sacrum backward
Innominates
· This study showed posterior rotation of both?????
· Other studies have shown more of a shear with one innominate rotating – this makes more sense to me.
Coccyx
· The Bo article sited (2001) is a well know study and did not test unilateral PFM contraction as is stated in the article.
Muscle activation – authors admit the majority of the effect is from the glut max.
This article attempts to address a very deep question – does unilateral PFM spasm move the pelvic bones. I would say they did not convince me. Good method but wrong method of PFM stimulation.
I see unilateral PFM shortening and SIJ dysfunction clinically and suspect the PFM does not actually move the bones but may increase strain of on SIJ enough to cause symptoms under some conditions. This question remains to be answered.
2011 schedule
March 9 – Beth Shelly
April 6 – Beth Shelly
May 4 – Jane O’Brien
June 8 – Pam Downey
July 6 – Ann Dunbar
August 10 – Michelle Spicka
September 7 – Pam Downey
October 5 – Jane O’Brien
November 9 – Beth Shelly
December 7 – TO BE DECIDED
Thanks Beth for leading this great discussion!
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