Postural control in women with urinary incontinence

1. The main aim of the project is an objective evaluation of posturography recordings in dynamic (gait) and static conditions. The target population in this study will be postmenopausal women suffering from stress urinary incontinence (group A) and continent women (group B). We will assess possible differences in postural stability between the groups and whether bladder filling has any effect on posturography recordings. The measurements will be performed under standard testing conditions, the same for all subjects. The subjects will be requested not to engage in intense physical activity 24 hours before the measurement. They will also be asked to prepare comfortable clothes that would not restrict movement and remain barefoot. They will first pass urine and will perform trials with the empty bladder; afterwards they will drink 3 glasses of water (750 ml) in less than or equal to 15 minutes. After declaring the need to void, bladder volume will be measured with real-time ultrasonography. Patients will rest comfortably in a supine position. The examiner will place the US probe at two fingers over the pubic symphysis (abdominal midline). Measurements will be taken with Toshiba Famio 8 ultrasound. Volumes will be calculated as the product of 3 internal bladder diameters (height x width x depth x 0.52). Three measurements will be taken and the arithmetic mean calculated. The measuring methodology has been verified in the study of Poston et al. [Poston G. J., Joseph A. E. A., Riddle P. R.: The accuracy of ultrasound in the measure¬ment of changes in bladder volume. Brit. J. Urol., 1983, 55, 361] When the urine volume will greater than or equal to 250 ml, the woman will again undertake trials on a force platform. The portable AMTI platform (AccuGait) allows the measurement of objective parameters of balance while the synchronous use of two platforms helps gait assessment. Data acquisition and export will be carried out using the AMTI's NetForce software. The results will be then processed with Matlab software (Mathworks, Natic, MA United States) The platform sampling frequency will be set at 100 Hz . The study participants will be instructed to stand barefoot in a comfortable position with their arms along their sides and to look forward. Before each session, the subjects will have enough time to practice walking on the force platforms. One-platform test will consist of: a/ Two 60-second trials in a quiet standing position were recorded for each of the four testing conditions: eyes open/full bladder, eyes open/empty bladder, eyes closed/full bladder, eyes closed/empty bladder. Slomka et al. have demonstrated high reliability of two trials of rambling and trembling measurements (Slomka K, Juras G, Sobota G, Bacik B. The reliability of a rambling-trembling analysis of centre of pressure measures. Gait Posture 2013;37(2):210-213). b/ Two lean-forward trials to the limits of stability (LOS) with movement at the ankles only. The protocol of LOS will consist of three phases: 1st phase – 10s of quiet standing, 2nd phase – the maximal forward-lean in a self-paced manner, and 3rd phase – maintenance of the maximal forward-lean. Two-platform test (Platforms A and B) will comprise 4 trials (12 repetitions): a/ Three repetitions: quiet standing on platform A for 15 seconds, then changing to Platform B (1 step) followed by quiet standing for another 15 seconds. The distance between platforms: 10cm. b/ Three repetitions–quiet standing on Platform A for 15 seconds, then changing to Platform B (1 step) followed by quiet standing for another 15 seconds. A 15-cm obstacle over the edge of the platforms; the distance between platforms: 10 cm. c/ Three repetitions – quiet standing on Platform A for 15 seconds, then changing to Platform B (1 step up) followed by quiet standing for another 15 seconds. Platform B is placed on a 17-cm base directly at the edge of Platform A. d/ Three repetitions – quiet standing on Platform B for 15 seconds, then changing to Platform A (1 step down) followed by quiet standing for another 15 seconds. Platform B is placed on a 17-cm base directly at the edge of Platform A. Participants will need to attend the examination once only including participation in an empty bladder and full bladder trials. The duration of the examination will be approximately one hour. Platform changing will start at a light signal displayed in the following sequence: red, orange, green. The participants will change platforms after the green light comes on.