Optimal Span between Feet of Public Squat Toilet Based on Anthropometric Data and Squatting Stability Assessment

Abstract: Sitting toilets are preferred globally because they afford a relatively comfortable posture.

However, squat toilets are among the most common toilets in numerous public areas because of their

advantages, including personal hygiene, easy cleaning, and health bene?ts. This study attempted

to determine optimal toilet design parameters and recruited 50 Taiwanese and 50 Southeast Asian

women and collected span between feet (SBF) data for participants squatting in their most comfortable

posture, and also surveyed maximum outer width (MOW) data of 28 public squat toilets in Taipei.

Finally, we compared the squatting stability levels of 40 female participants (20 Taiwanese and 20

Southeast Asians) who squatted for 2 min at comfortable SBF and MOW-based SBF values. The results

revealed that the minimum and maximum SBFs of Taiwanese were 14.52 cm and 18.40 cm, and that

of Southeast Asians were 15.64 cm and 20.40 cm, respectively. No signi?cant difference was observed

in the SBFs between the two groups was observed. The mean (range) MOW of the surveyed toilets

was 27.7 (27–29) cm. Analysis of variance results showed no difference in stability between the two

SBFs. This implies that the comfortable SBF (i.e., 16 cm between the participants’ heels) was narrower

than the MOW, as commonly used, indicating that the comfortable SBF can be considered as an

optimal toilet width parameter because of its constant stability.

Keywords: squatting-type toilet; span between feet (SBF); stability; comfort

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