適當的排尿姿勢有助於改善膀胱排空效率

侯心一、羅晶、陳浩瑋、阮雍順、陳妤甄

高雄醫學大學附設醫院 泌尿科

Adjusting Voiding Posture Improves Bladder Emptying Efficiency

Hsin-I Hou, Jean Luo, Hao-Wei Chen, Yung-Shun Juan, Yu-Chen Chen

Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan

Purpose: Different toilet designs lead women to adopt various voiding positions, including semi-squatting, full squatting, and sitting. This study aimed to compare the voiding parameters from free uroflowmetry and post-void residual urine among different voiding positions and to assess their potential implications for voiding efficiency and public health hygiene.

Materials and Methods: This prospective study was conducted between August 2024 and March 2026. Healthy female volunteers aged ≥18 years were recruited. Participants without lower urinary tract symptoms or urinary tract infection were eligible for inclusion. Participants were instructed to void in three different positions: Group (A) semi-squatting (anterior superior iliac spine [ASIS] positioned higher than the knees), (B) sitting (ASIS level with the knees), and (C) full squatting (ASIS positioned lower than the knees) (Figure 1).

Uroflowmetry was performed using a urodynamic system to record average flow rate (Qavg), maximum flow rate (Qmax), voided volume, voiding time, and voiding pattern. After voiding, post-void residual urine (PVR) was measured using a portable bladder scanner. Voiding efficiency (VE) was calculated as follows: VE (%) = voided volume / (voided volume + PVR) × 100. Each measurement was performed three times, and the mean value was recorded for analysis. Participants were allowed adequate hydration and rest between measurements. If the voided volume was <150 mL, the measurement was considered inadequate, and the participant was asked to repeat the test on another day when a stronger urge to void was present.

Differences among the three voiding positions were analyzed using repeated-measures analysis of variance (ANOVA) with post hoc pairwise comparisons. This study was approved by the IRB of Kaohsiung Medical University Hospital. (KMUHIRB-E(I)-20240400)

Results: A total of 31 participants met the inclusion criteria. Voiding posture significantly affected bladder emptying parameters. Both PVR and VE differed significantly among the three groups (p = 0.004 and p = 0.002, respectively). Post hoc analyses demonstrated that the semi-squatting position was associated with significantly lower voiding efficiency compared with the sitting (p = 0.010) and full squatting positions (p = 0.041). In addition, PVR was significantly higher in the semi-squatting position than in the sitting position (p = 0.002) (Table 1).

Conclusion: Voiding posture significantly influences bladder emptying efficiency in healthy women. Sitting and full squatting positions are associated with more effective bladder emptying compared with the semi-squatting position. These findings suggest that adopting an appropriate voiding posture may help improve voiding efficiency and potentially reduce residual urine.

Figure 1. Voiding positions.
(A) Semi-squatting position; (B) sitting position; (C) full squatting position.

Table 1. Comparison of uroflowmetry parameters among different voiding positions

Values are presented as mean ± standard deviation (SD)
* indicates a statistically significant difference (p < 0.05)
A, semi-squatting position; B, sitting position; C, full squatting position.