In this episode of Behind the Breakthroughs: Off The Field, we dive into the world of joint hypermobility with postdoctoral researcher Dr. Tessa Hulburt. While being "double-jointed" might seem like a simple quirk, for a significant portion of the population, it is linked to chronic, widespread pain. Dr. Hulburt discusses the unique biomechanical challenges faced by those with hypermobile joints, from increased risks of dislocations to the chronic fatigue caused by muscles working overtime to stabilize the body. We explore how her latest research, involving complex neuromuscular tasks like jumping and landing, is working to bridge the gap.
Here's the article referenced in the episode:
Hulburt, T. C., Black, W. R., Bonnette, S., Thomas, S., Schille, A., DiCesare, C., Briggs, M. S., Ounpuu, S., Kashikar-Zuck, S., & Myer, G. D. (2025). Does joint hypermobility exacerbate altered landing and jumping strategies in adolescents with fibromyalgia syndrome compared to controls?. Clinical biomechanics (Bristol, Avon), 124, https://doi.org/10.1016/j.clinbiomech.2025.10646.
Melissa: Welcome to Behind the Breakthroughs. I'm Melissa Deuber from the Woodruff Health Sciences Center Library. In each edition, we take a closer look at the research shaping health, healing, and human performance at Emory. Today's episode is part of the Off the Field series, where we explore how science moves from the lab to everyday life. I'm joined by Dr. Tessa Hulburt to talk about their work, the questions that drive it, and what it could make possible. So let's get started with a brief introduction. If you could tell me a little bit about yourself and how you got into this line of research?
Dr. Hulburt: Yeah, absolutely. I've always been interested in movement and biomechanics and got the opportunity to work in a baseball pitching lab and learn about the biomechanics of pitching. From there, I really got interested in sports biomechanics and specifically was interested in figuring out how we could take what we were learning in the world of sports biomechanics and apply that to those who are experiencing more complex medical problems, specifically those with chronic pain. This really motivated my transition here, where I work at SPARC as a postdoc, studying how movement affects pain and how pain affects movement.
Melissa: That's great. For someone who's never heard of joint hypermobility, what is it and why does it matter when it's painful?
Dr. Hulburt: We call it joint hypermobility when you can extend a joint past its normal range of motion, but it can be so much more than that. Epidemiological studies vary, but our very best estimates show that something like 10 to 40% of the population has hypermobility in at least one joint. For some, this hypermobility occurs all over the body, something that we call generalized joint hypermobility, and it might have a genetic component. We still don't know why, but for some, this hypermobility that's happening all over may lead to significant pain in their joints and their muscles.
Hypermobility itself is common, and painful hypermobility actually may be more common than we previously thought. Studies have found incidence rates for painful joint hypermobility ranging anywhere from 0.75 to 3.4% of the population, and some studies have also pointed to hypermobility being a part of some patients who have rheumatologic conditions. Again, this is something that might be more common than we previously thought.
The reason why this matters is because the presence of hypermobility in a person with chronic widespread pain may fundamentally influence why they are experiencing this pain. Purely from a biomechanical context, hypermobility causes ligaments and tendons to be extra stretchy, such that they're unable to stabilize joints. This creates an increased risk for large joint movement, such as subluxations and dislocation injuries, as well as smaller joint movement or micromotion in the joints, which may be very painful as well.
Further, muscles have to work very hard to maintain stability, which can cause excess fatigue, both in those muscles that are working so hard but also centrally in the whole body, which we're recognizing more as chronic fatigue. Despite this, hypermobility is often overlooked as a contributor to pain due to lack of awareness, the misconception that the condition is rare, and a lack of effective treatments. Patients might be treated for their chronic pain without considering hypermobility, which may result in treatment failure because that underlying cause is not being addressed.
Melissa: So, if you had to explain what your study is really about to a friend or family member who maybe doesn't work in science, what would you say?
Dr. Hulburt: I would say a mainstay for treatment for painful hypermobility is physical therapy, exercise, and movement-based therapy. Movement-based therapy can be really effective in that it can strengthen muscles around hypermobile joints to better support them, thereby reducing those dislocation and subluxation injuries, and maybe even reducing that joint micromotion, which can also be a big contributor to pain.
We do have evidence-based recommendations for movement-based therapy for those who have chronic widespread pain that are not hypermobile, and those can be very effective. Those recommendations tend to focus on exposing the body to movement in a gentle and graded approach. Though that approach can be effective for those with hypermobility in addition to their pain, we have to consider the additional injury risk that is associated with hypermobility.
We need movement that is challenging enough for the muscles to build that needed strength, while remaining gentle enough to avoid damaging those hyperflexible joints. In practice, threading this needle is incredibly challenging, and we don't currently have evidence-based recommendations for movement, leaving patients with little else but their symptoms to figure out how to use movement as a pain treatment.
This requires patients to be very hypervigilant of their symptoms while trying a battery of movements in hopes of finding something that their body can tolerate. We really need evidence-based protocols for movement-based therapy to better support patients in this process. In order to develop that understanding for how to use movement as a pain treatment, we need to first understand how hypermobility underlying chronic pain alters how we move, so this study contributes to this understanding. From there, we can develop targeted treatments.
So our study, we compared three groups: we compared adolescents with chronic widespread pain alone, those who had hypermobility in addition to their chronic widespread pain, and those who had neither (our control group). And we compared the biomechanics of these three groups during a complex neuromuscular task, which was a landing and jumping task, to better understand how pain alters movement and then how hypermobility may further alter movement in those who have pain.
Melissa: So when you first started this project, I think you mentioned this a little bit, but what was kind of the main question you were trying to answer?
Dr. Hulburt: Yeah, so as I mentioned, we do have evidence-based movement therapy recommendations for those with chronic widespread pain. However, these recommendations are not necessarily a good fit for those who have hypermobility underlying their pain. We do have theories as to why, but we don't have a good understanding of what this looks like in practice. We know the injury risk is higher and that damage can be caused to hypermobile joints if we aren't careful with how we're recommending patients move, but these injuries and the long-term damage can take time to manifest.
This makes it really difficult for physical therapists and patients to figure out what movement is helpful and what movement is hurting them. And there's a gap in research for how our theories about hypermobile movement looks in practice. So when we understand how the hypermobile body moves and how it moves differently, from there we can develop targeted treatment.
And further, we know that pain alters movement; however, I was surprised to learn that there are very few studies that have compared how those who have chronic pain alone move and how they might move differently from those who have hypermobile chronic pain. This is really key to understanding how we can alter movement-based therapy recommendations for chronic pain patients to work for those who have hypermobility underlying their pain.
Melissa: So has any of this data surprised you or kind of forced you to rethink an assumption that you previously had?
Dr. Hulburt: Yeah, absolutely. I think our main outcome was a bit of a surprise. We did find that pain altered joint movement, which we measured as joint angles, and it also altered joint forces, which we measured as moments, compared to our control group. So it was clear that those with pain completed this task very differently. The surprising outcome was that the hypermobility, so comparing that non-hypermobile pain group to our hypermobile pain group, did not significantly alter movement during this task.
So when looking at the three groups together, poor mechanics exhibited by both pain groups were worse in the group who had hypermobile pain compared to controls, meaning that hypermobility may have further exacerbated altered movement. However, it did not differentiate between the hypermobile and non-hypermobile pain groups. One possible interpretation is that this task may have been too challenging, introducing a ceiling effect where further movement alteration couldn't be detected. Further, this movement task was not designed to detect movement differences due to hypermobility, so perhaps with a task designed for this population or maybe a variety of tasks designed to detect various movement deficits due to hypermobility, we would be able to better understand how movement is different for those who have hypermobile pain.
Melissa: Great. So how is this study motivated the future directions of this research or maybe even your research?
Dr. Hulburt: Yeah, this study made it clear that we need to take maybe a step back in order to take a step forward. So what we found was that this particular task didn't elucidate movement differences for those with hypermobile pain, but perhaps a task that is designed for those with hypermobility or a variety of tasks designed to target different aspects of how hypermobility might alter movement would be better suited to figure out how those with hypermobility are moving differently.
So moving forward, we're interested in developing either a task or, more likely, a protocol of different tasks that are designed to do just that- that can accomplish both developing a comprehensive understanding of how hypermobility is altering how people move, but also something that could be potentially used as a standard to assess movement differences in patients before designing more individualized treatment.
Melissa: That's a great point that you brought up, that not every single study can result in a breakthrough. Sometimes the biggest finding of the study is that you need to redesign it, which is still a great finding.
So thank you so much for speaking to me, and thank you for joining us for this episode of Behind the Breakthroughs Off the Field. I hope today's conversation offered a clearer look at the curiosity, care, and science behind the work happening at Emory. If you enjoyed this episode, feel free to explore the rest of the series, where each researcher brings a new perspective on injury prevention and human performance. Thanks for listening, and we'll see you next time.