I had never heard of the shin box until a couple of weeks ago, but I have been playing around with it for my hips multiple times a day since then. It is a pretty basic exercise, but there are tons of variations and progressions you can try. Horizon Fitness says:
The Shin Box Switch covers many bases, including working on hip internal/external rotation, improving the length of the hip flexors, and activating the glute muscles.
For those who may sit a lot during the day, this could be the key exercise in helping your body counteract the debilitating effects of prolonged sitting. By providing greater flexibility through the hips, the Shin Box Switch can result in less chance of injury and low back pain, as well as better overall movement and function.
And, from a pure fitness and exercise standpoint, the Shin Box Switch can be valuable in improving your range of motion and making your lower body strength exercises (squats, deadlifts, lunges, etc.) much more efficient.The funny thing is that I have been looking forward to seeing The Gun Runners movie for awhile and it is finally viewable and free on Netflix this month. Half way through the movie, a bunch of elite Kenyan runners are warming up in Iten, Kenya and what are they doing? The Shin Box. They even have a way of using their hand to hold their head in a way I had not seen and that works well for the posture.
I did purchase a course through Move Perfect for a bunch of the progressions that I might need. My hips have kept me for running since my hip surgery in 2011, so I am willing to give this a shot.
Here is a brief look at the basic shin box. If you are really tight and just starting out, you can lie down. Progressions take you to standing up. I am not there yet.