Playground for elderly persons

Via delicious, I ran across this short news in Times about playgrounds for elderly persons:

The idea was hatched in Finland, where researchers have experimented with what they call “three-generational play”.

The University of Lapland found that a combination of climbing frames, swings and seesaws had significantly helped old people to regain confidence in their bodies. Forty test patients aged between 65 and 81 showed improvements in balance, co-ordination and speed after using a playground for three months.

Why do I blog this? that's relevant, when thinking about social cohesion and urban planning, why not devoting places for people that would enjoy such activities. Much of the energy is focused on kids playground, why not thinking about other users. This does not mean that it should be a parkour for elders but there is surely a design issue here.