expression, godan verb (-su)
stretch one's legs out; relax with legs extended
Physical action of extending the legs, often to relax after sitting or being in a cramped space.
新幹線で隣の席が空いたので、足を伸ばして座れた。
The seat next to me on the Shinkansen was empty, so I could sit with my legs stretched out.
expression, godan verb (-su)
go a little further; extend one's walk
Idiomatic use: after reaching a destination, to continue walking a bit more to another place, often for leisure or sightseeing.
せっかく京都に来たから、嵐山まで足を伸ばそう。
Since we came all the way to Kyoto, let's go a little further to Arashiyama.