Translation guide
The bottom surface of the foot. In Japanese, this is most commonly expressed with the noun 足の裏 (あしのうら). There are also specific terms for the arch and the entire sole.
The underside of the foot that touches the ground when standing.
The most common and natural way to say 'sole of the foot'. Literally 'foot's back/reverse'.
The curved part of the sole that doesn't touch the ground.
The whole bottom of the foot from heel to toes.
Anatomical term for the plantar surface. Rare in everyday speech.
While 底 (そこ) means 'bottom', 足の底 is not idiomatic for 'sole of the foot'. Use 足の裏 instead.
Please show me the sole of your foot.
The sole of my foot hurts.
I got a blister on the sole of my foot.
A slightly more technical or written compound meaning 'sole of the foot'. Used in medical or sports contexts.
Strengthen the arch of the foot.
Specifically the arch of the foot. Literally 'the part that doesn't step on earth'.
I sometimes get cramps in the arch of my foot.
I was diagnosed with plantar fasciitis.