Researchers at Kingston Health Sciences Centre (KHSC) and Queen’s University’s Smith Engineering have released findings that could present a major step towards towards an evolved understanding of joint health and injuries.
The first of its kind study in Canada is using advanced imaging technology to get a more complete picture of how a human shoulder moves, providing insights that could be used to make impactful changes in injury prevention, rehabilitation, and reparative surgery.
The study was conducted at the Skeletal Observation Laboratory at Hotel Dieu and uses biplanar videoradiography (BVR) to accurately view the shoulder bones moving underneath the skin in real time.
Erin Lee, lead author of the study and a former PhD student at Queen’s, says that still x-ray images have typically been used when studying the shoulder, which forces assumptions to be made about how bones are moving relative to how the skin is moving.
With a joint as dynamic as the shoulder, she says that often results in errors in the calculations made.
“What’s really novel about this equipment that we’re using is it allows us to see how the bones are moving directly,” Lee said.
“Especially in joints like the shoulder, if you just feel your shoulder blade, you can feel that the shoulder blade, it moves a lot beneath the skin.”
The system used for imaging is not common, with the lab being one of only two in Canada boasting the equipment due to its complex setup and the technical expertise needed to make use of it.
Michael Rainbow, the director of the Skeletal Observation Laboratory and an associate professor of Mechanical and Materials Engineering at Queen’s, has previously used the imaging technology to explore the fundamental movement of the foot and ankle – another area of the body containing a bevy of different bones.
Because of the complexity of the shoulder joint, it’s been understudied, and Dr. Rainbow says that can lead to a somewhat misguided approach to injury treatment.
“This kind of research allows us to revisit long-standing assumptions about how the human body works. Many of those assumptions have shaped treatment strategies, yet they were made before we could directly measure skeletal motion,” Rainbow said in a press release.
“This kind of study is essential for designing better treatments in the future.”
Lee, whose PhD studies focused on shoulder motion and mechanics, says there are two primary goals to the research that could help reshape injury prevention and recovery.
The first goal, and the focus of the published findings, is to discover and implement a better understanding of the function of a healthy shoulder – but that the imaging technology could one day also more closely explore the differences in shoulder function between individuals.
“It’s mainly just generally what are the patterns we see across our samples, but then also how much does that vary across people,” Lee said.
“On average, for every amount of five degrees you raise your arm, you might see two point five degrees of how much your scapula rotates. But with our technology, we can really get at that with more granularity and see if there is our differences across people, and we absolutely find that people vary. We’re not all the same and we don’t all move the same, and that has relevance for later on disease progression as well.”
Given the rarity of these machines, individuals won’t soon be able to know exactly how their own shoulders move, but the discoveries could help to inform treatment plans in professions like physiotherapy sooner than later.
Lee says with so many assumptions made about the healthy motion of a shoulder, some best courses of treatment might actually be damaging to certain individuals rather than helpful.
She says the research could ultimately give the field more tools to work with to support more individualized recovery plans.
“With any sort of treatment, there are some patients who benefit from it and some patients who don’t, so I think that this kind of research where we can get into the more the individuality of it and see how people vary.”
“A lot of those assumptions are based off of how we think the healthy shoulder works, but really we haven’t fully uncovered that. So we’re kind of early in this knowledge to action plan, where right now we’re trying to uncover, is there really such thing as this healthy movement pattern?”
