If there is no exercise to the body definitely every person will get health problems.
In his age ask him to walk how much he can, any times in a day for 5mins each time.
When he is sitting in chair tell him to move his toes, ankle, leg in up and down motion. Slight neck movements. He can even stretch his body by lifting his hands.
Do not lie on same side. If he lie flat on back for 2hrs, try to lie another 2hrs in left and right sidelining alternatively.
While lying also he can do exercises by moving all joints like toes movement, ankle ( which is best exercise) folding knee, moving fingers, wrist, hand movements, he can deep breathing exercise on lying position.
Answered2016-09-24 11:19:24
Let others know if this answer was helpful