Electrode Placement

Bi polar electrode placement was shown to produce as equally effective stimulation as quadripolar electrode placement (Dumoulin et al., 1995). This electrode placement is seen to be preferential based on the relative ease of its application, and can be seen in the image below:

(Dumoulin et al., 1995)

The pudenal nerve, the nerve which we target when we use electrical stimulation to contract the pelvic floor is located approximately 7.5-10cm within our pelvic cavity. Therefore the intensity (amplitude) required to produce a contractions of the pelvic floor can cause painful sensations;  understandably resulting in apprehension and discomfort for the user. The user's discomfort is often the limiting factor in obtaining an effective contraction of the PFM. Discomfort can decrease the effectiveness as the intensity required to maximally contract the PFM is often intolerable to the user.

A study by Dumoulin et al., 1995, comparing the placements of 2 surface electrode during stimulation of the PFM in continent women, reported that particular discomfort was experienced by participants, who were using bipolar interferential.  Understandably as the electrodes were placed posteriorly between the ischial tuberosities over the anus and anteriorly over the clitoral region. Maximal discomfort was felt by the women under the anterior electrode due to a high levels of current, focused on such a small sensitive area.

Because of the discomfort felt by the women an alternative electrode placement was suggested to decrease their discomfort. The anterior electrode was re-positioned above the pubic symphysis, which in theory:

·         Increases the current spread to ~140cm (Laycock & Green 1988). 

·         Decrease pain

·         Potentially increase stimulation of motor nerve of the pubococcygeus muscle.

A Vaginal pressure probe (manometer) was used to measure the strength of the PFM contraction with the new electrode positioning and no differences in maximal contraction (amplitude) were observed between the different electrode placements. 

REFERENCES:

Dumoulin, C., Seaborne, D., Quirion- DeGirardi, C.  & Sullivan, S. (1995). Pelvic- floor rehabilitation, Part 1 : Comparison of two surface electrode placements during stimulation of the pelvic-floor musculature in women who are continent using bipolar interferential currents. Physical Therapy. 75 (12) 1067-1074.

Laycock, J. & Green, R. (1988). Interferential therapy in the treatment of incontinence. Physiotherapy. 74: 161-168.