I was surprised when reading in another thread (about internal/external emptiness and unperurbedness) to read that in MN 122 ( http://www.accesstoinsight.org/tipitaka ... .than.html
it says the following:
"If, while the monk is dwelling by means of this dwelling, his mind inclines to walking
back & forth, he walks back & forth [thinking,] 'While I am walking
thus, no covetousness or sadness, no evil, unskillful qualities will take possession of me.' In this way he is alert there.
In this excerpt the "dwelling by means of this dwelling" refers to fourth jhana
....or at least the monk being described goes to fourth jhana
before starting a rather long series of contemplations which culminate in this and similar statements about talking etc.
I guess this is saying that it is possible to walk while in fourth jhana
. I still am not certain whether in the many suttas where concentration is first established (jhanas) and then contemplations occur whether after the jhana
is established it continues throughout the contemplations...seems like it does as there is nothing to indicate that it dissipates.....but I don't know for sure.
Anyway...so far there seems to be some evidence suggesting that walking
may be possible in first jhana
and now this seems to indicate that there can be walking
in fourth jhana
....makes me think that it might be possible in the second and third also...don't know.