Yes, you can massage on the shoulders (and hips) to benefit the hips. But further, I mean the shoulder reflexes can help the hips and likewise the hip reflexes can help the shoulders. This goes along with more such correspondences, for instance the feet reflex to the hands, the calves to the fore arms, the knees to the elbows, the thighs to the upper arms, and as we mentioned, the hips to the shoulders.
And then vice versa for each of these: the hands reflex to the feet, the forearms to the calves, the elbows to the knees, the upper arms to the thighs and the shoulders to the hips. So for instance, if part of the arm hurts, needing help, then in addition to doing the arm reflexes on the hands and feet, work the corresponding part of the leg.
And so on. Even the bottom of the spine reflexes can need reflex work to help the neck! To take it further, if one's hip stops hurting, the shoulder might start hurting instead. If the knee stops hurting, the elbow might hurt instead, etc. Of course this then relates back to the recommendation of a full session, covering all the reflexes in the hands and feet, and repeating, intermittently, the reflexes one feels more.
And of course to recommending that we should do more healthy lifestyle improvements, to holistically help the whole body (and mind and soul).
So, there is more than the basic wonderful reflexology charts.