Activation of Pelvic Floor Muscle During Ankle Posture Change on the Basis of a Three-Dimensional Motion Analysis System

BACKGROUND: Weak pelvic floor muscles (PFMs) is an important cause of stress urinary incontinence. Effective strengthening of PFMs is very helpful in improving lower urinary tract disease. The purpose of this study was to determine the activation of PFMs in accordance with movement of the pelvis and ankle. MATERIAL/METHODS: Fifty healthy adults who underwent PFM contraction in ankle posture change (dorsiflexion, neutral, and plantar flexion) while standing were simultaneously measured using electromyography and motion capture systems. Muscle activity at the tibialis anterior and gastrocnemius muscles was measured by surface electromyography electrodes and PFMs was measured using anal/vaginal probe. Motion analysis was captured by 3-dimensional motion trajectories of the retro-reflective markers. RESULTS: At the ankle dorsiflexion, pelvic tilted anteriorly and PFMs were activated, but there was no pelvic movement in ankle plantar flexion. Significantly greater PFM activities were seen in ankle dorsiflexion. CONCLUSIONS: PFM exercises performed in active ankle dorsiflexion positions while standing may increase the effectiveness of these exercises. For an effective pelvic floor enhancement in patients with weak PFMs, we recommend a dorsiflexion of the ankle in the standing position.