The objective effects of different postures on micturition have been studied and the results remain controversial. The aim of this study was to evaluate different voiding position on subjective and objective voiding efficiency in healthy volunteer young women.

To ensure the result was out of influence of aging and menopausal effect on the voiding function, we recruited 33 young healthy volunteers (most of them are registered nurses, mean age=28.9 years) who were without pelvic organ prolapse and lower urinary tract symptoms (LUTSs). All participants  urinated in three postures: sitting, squatting and sit-trunk-thigh angle ≥15°. Uroflowmetric parameters such as maximum flow rate, flow pattern, flow time and electromyography were collected using a weight transducer urodynamic device for comparing and post-void residual (PVR) was measured by intermittent catheterization in each position. Voiding diary of five times of bladder capacity (BC) of each participant was recorded at home before uroflowmetry study. Subsequent bladder capacity in filling cystometry was controlled according to individual’s first voiding volume and her PVR. The BC of the three postures was controlled into the same volume (mean BC: 271 ml). Subjective voiding feelings of each voiding posture were measured by visual analogue scale (VAS 0-10) after completing three voiding episodes. Pair t test was used to compare difference of uroflowmetric parameters and subjective feelings of voiding postures.

The maximal and average flow rates of squatting and sit-trunk-thigh angle ≥15° were significantly higher than those of sitting posture (Table 1). PRV and subjective voiding feeling of sit-trunk-thigh angle ≥15° were significantly better than those parameters of squatting and sitting postures.

The maximal flow rates and PVR of squatting is higher than those of sitting and sit-trunk-thigh angle ≥15°. This phenomenon is contradicted. VAS score ( 6.9±1.9) in voiding with squatting posture imply voiding with squatting is not comfortable and voiding efficiency is not good. All parameters are statistically significant difference while sit-trunk-thigh angle ≥15° than while sitting imply that we may urinate with a sit-trunk-thigh angle ≥15° to get a more effortless voiding and better bladder emptying. Our results reveals that higher VAS score ( 8.1±1.6) in voiding with posture of sit-trunk-thigh angle ≥15° is corresponded to lesser PVR in the same posture, which shows that objective findings are compatible with subjective satisfaction although time to void is significantly longer while sit-trunk-thigh angle ≥15°than while squatting and sitting.

The voiding position literally do impact the urodynamic measurements and facilitate micturition. Our findings found voiding in sit-trunk-thigh angle ≥15°rather than in sitting or squatting, which encourage performing urodynamic examination in this posture may obtain a better result. We need conducted more LUTS patients to get a more precise result.

Effects of posture and squatting on the dynamics of micturition. M B Bush 1, B Liedl, F Wagenlehner, A Yassouridis, P E Petros Int Urogynecol J. 2015 May;26(5):779-80
Voiding position does not affect uroflowmetric parameters and post-void residual urine volume in healthy volunteers Ali Unsal 1, Ersin Cimentepe Scand J Urol Nephrol. 2004;38(6):469-71.
Posture and micturition: does it really matter how a woman sits on the toilet? Ajay Rane 1, Jay Iyer. Int Urogynecol J. 2014 Aug;25(8):1015-21

Continence 12S (2024) 101572
DOI: 10.1016/j.cont.2024.101572