Investigation of optimal cues to instruction for pelvic floor muscle contraction: A pilot study using 2D ultrasound imaging in pre-menopausal, nulliparous, continent women.

Investigation of optimal cues to instruction for pelvic floor muscle contraction: A pilot study using 2D ultrasound imaging in pre-menopausal, nulliparous, continent women.  Crotty K, Bartram CI, Pitkin J, Cairns MC, Taylor PC, Dorey G, Chatoor D. Neurourol and Urodynam 2011 30:1620-1626.

Beth Shelly  March 7, 2012

Primary aim – to investigate which cue for PFM contraction results in the best overall contraction and elevation of the urethra.

Subjects

Continent, nulliparous, pre-menopausal women, who could perform an “inward moving PFM contraction” on US and contract various portions of the PFM on EMG. 

All subjects received the same instruction – no control group – no blinding of subjects or trainers. 

US angle of urethral inclination was read by 2 blinded practitioners experienced in reading US.

Study design / method

Type of study – quasi experimental

PFM exercises with three instructions

·         Squeeze and lift from the front as if stopping the flow of urine (anterior)

·         Squeeze and lift from the back as if stopping the escape of wind (posterior)

·         Squeeze and lift from the front and the back (combined)

Session one used US to confirm elevation of PFM then instructed HEP - 5 sec hold, 5 sec rest, 3 reps max effort 1 set per day in supine and 1 set per day in standing, with each of the three directions – total per day 18 for 2 weeks primarily for learning.

Session 2 used EMG (initially external with some difficulty, then internal vaginal) to assess patient’s ability to contract the PFM as directed. As the PFM is smaller anterior a constantly lower EMG reading with anterior cue was taken as correct technique. Participants practiced for 2 more weeks as above

Assessing the outcome

Intension to treat was not used as the initial goal was to create maximum homogeneity in study population – all able to contract the PFM in three different ways listed below.

32 started and 17 were eventually analyzed.  Does this represent a too narrow group? I would say it is not generalizable to patients. 

Data collection was using 2D perineal RTUS, same exercise set was used in random order.

Angle of inclination (AUI) – center pubic bone and center urethra. Three reps were averaged. Picture bottom of page 1623

Results

Posture – bladder neck is more elevated in supine (more acute AUI) – I would like to see the rest data and then to compare rest to contract to see if the change is similar in stand and sit but the bladder starts lower in standing. Cue did not change this finding

Cue – ave 4 degrees more acute with posterior or combined cue

Discussion

Which muscle of the pelvic floor elevated the bladder neck?  The pubovisceral / pubococcygeus muscle is in a good anatomical position close to and elevate the urethra but this study appears to implicate the role of the posterior muscles – puborectalis. In addition mid vaginal high pressure zone during PFM contraction is related to increased posterior-anterior pressure (not lateral compression).  Posterior focused contractions would also likely activate the illiococcugeus which elevated the posterior position of the levator ani – not sure how this contributes to bladder neck position but would assist with elevation of all organs? Long muscle of the anus is also mentioned.  Does anyone have info on this muscle?

Conclusion

In “normals” PFM contraction with posterior or combined anterior and posterior focus results in 4 degrees more urethral support than anterior focused exercise only.  Results are not position dependent.  Results imply contraction of puborectalis and other posterior muscles in important for effective PFM training.