Pelvic floor muscle activity during jumps in continent and incontinent women: an exploratory study

Stress urinary incontinence (SUI) symptoms can be provoked during impact loads such as vertical jumps. To investigate and compare pelvic floor muscle (PFM) activity in women with SUI and continent women (CON) during drop jumps (DJ) and counter movement jumps (CMJ) could clarify the activity of the PFMs during impact loads.

A tripolar vaginal probe was used to record surface electromyographic (EMG) activity of the PFMs during DJ and CMJ. Time intervals of 30 ms were used to parameterize data from 30 ms before (pre-activity) to 150 ms after (reflex activity) ground contact on a force plate during the landing and take-off phase. EMG signals were normalized to the mean of the peak values of two maximal voluntary contractions (MVC) and expressed in percentage (% MVC).

For all time intervals during the landing and take-off phase, no statistically significant differences could be found between women with SUI and CON. EMG values exceeded 100% MVC for all time intervals during all landing and take-off phases. Maximal PFM activation was measured during the first landing of DJ and was 404.1% MVC for SUI and 370.2% MVC for CON.

Vertical jumps seem to stimulate pre-activity before and reflex activity after ground contact during the landing phase and activate PFMs up to 400% MVC. Jumping stimuli inducing involuntary PFM contraction could show a beneficial factor to be integrated in a PFM rehabilitation program.