Chazal talk about the danger of leaning to the right during the Seder meal. From speaking to people who know the anatomy of the windpipe and esophagus, they tell me they don’t understand the danger of one preceding the other. What did Chazal mean if our anatomy today seems to say that there isn’t a danger?
This is a good question. Chazal, based presumably on empirical knowledge of their time, assessed that leaning to the right involves greater risk than to the left. Rabbi Dr. Mordechai Halperin has suggested that the reason for this is the heightened chance of reflux (food coming up from the food pipe, which can enter the windpipe. Although this is not a great danger today, it is possible that eating habits in the past increased the risk.
Note that according to Rashi (Pesachim 108a), the idea of potential asphyxiation applies to eating while laying on one’s back, and not to leaning to the right. Rashbam disputes this, and see also Rosh. Thus, the question only applies according to the interpretation of certain rishonim.