The association between pelvic girdle pain and urinary incontinence among pregnant women in the second trimester.

OBJECTIVE: To examine the association among pelvic girdle pain (PGP), urinary incontinence (UI), and pelvic floor muscle (PFM) function in pregnant women in the second trimester. METHODS: Fifty-five pregnant women (29 with PGP and 26 without) were enrolled. Urinary incontinence was measured via the International Consultation on Incontinence Questionnaire-Short Form. Vaginal examination assessed PFM contract-relax patterns and muscle strength. RESULTS: Overall, 51 women (26 with PGP and 25 without) were included in the final analyses. After controlling for PFM muscle strength, women with PGP were significantly more likely to have UI (P=0.03). After controlling for pain status, having little or no PFM contraction was significantly associated with UI (P=0.03). There was no association between PGP and PFM weakness. CONCLUSION: There was an association between PGP and UI and between UI and PFM weakness among the study participants. Lack of PFM weakness in women with PGP during pregnancy may reflect acuity of pain or measurement error.

Spike-timing-dependent plasticity induced in resting lower limb cortex persists during subsequent walking.

Transcranial magnetic stimulation (TMS) of human lower limb motor cortex paired with common peroneal nerve electrical stimulation produces a lasting modulation of motor cortex excitability following the principles of spike-timing-dependent plasticity. We previously demonstrated that this "paired associative stimulation" (PAS) protocol applied during walking induced a bidirectional modulation of cortical excitability. The present study tested the hypothesis that the excitability of lower limb motor cortex assessed during walking is increased when PAS is applied to the resting cortex. PAS was delivered as a block of 120 pairs at 0.5 Hz to healthy subjects (n=13) in three separate sessions. TMS intensity was related to the active threshold obtained in tibialis anterior (TA) during the late swing phase of walking. Therefore, intensities used were below resting thresholds. When PAS using TMS intensities above active threshold was applied to the resting cortex, the normalized amplitude of potentials evoked in TA during subsequent walking increased to 124%. Using the same parameters and applying PAS during the late swing phase of walking, response amplitude increased to 114% of baseline. When the TMS intensity was set to active threshold, PAS applied to the resting cortex did not significantly modulate cortical excitability.