Here's a presentation on Dynamic Digital X-ray on visualizing scapulohumeral rhythm in the shoulder and shoulder blade.
When I examine the shoulders of my patients, and I move the shoulder up to the side in abduction, I can see how the scapulohumeral rhythm is off. People shrug their shoulders to compensate for pathology within the shoulder joint. You can see scapular winging. But, when I look at these motion x-rays on this video, I could see the same shoulder shrugging that happens in my patients, but I can also see it in the bones. With the software that they use with dynamic digital x-ray, they can actually measure the angle between the humerus and the scapula. In the past, he would have to do this with static x-rays, which wouldn't give you a very good appreciation of how the shoulder is moving. Or, he would have to use a fluoroscopy machine, which would blast you with radiation.
This is exciting technology. It is also on my bucket list, or my wish list, for this practice. I would love to have dynamic digital x-ray to visualize what happens after a person is injured in a whiplash injury. As of now, the cost to bring a dynamic digital x-ray machine to the office is about $100,000. I think that could be doable with enough cases of whiplash injuries. It would be even better if someone would open up the radiology center in Petaluma that could perform the studies for me. As it sits right now, it's at the chiropractors once again to provide the imaging studies that we need.
At the 10:50 mark, the doctor is demonstrating a shoulder that is actively dislocating by abducting the arm, and having the patient rotate. You can see the shoulder dislocate under the skin. Static x-rays then show you that the joint is just decentering in certain positions. But, when you take a motion x-ray, you can really see the humerus subluxate across the genoid fossa.