Lately it seems that I have had several hip/back issues to deal with. And in each case teh remedy has been a functional hips stretch.
Have the individual stand on the effected leg and with the other foot have them perform a toe tap in the transverse plane allowing the hip to "open and close". Think of them standing on the fact of a clock with there right leg let's say. The right foot will be placed with the toes facing 12. With the other leg they will see how far they can reach, for example, can they reach from 2 and then pivot backwards and toe touch the 6? Do not hold at either position for any length of time. This is a very effective way to lengthen the external rotators (ERs) and teh internal rotaors (IRs) of the hips while weightbearing and against gravity.
Try it and see what you think.