🦀 PT Crab Issue 100 - We’re Back and We’re Bendy

It’s been a few weeks and things are really different over in the world of the Crab. Fortunately though, the Crab is mostly unchanged, these modifications just swirl around it. Since leaving you, I’ve had the opportunity to learn how to build a fence, how to make a mortgage payment, how to rehab a dog with a spinal cord injury, and how to finish a clinical rotation. I had mixed success in all of these areas, but the most important, IMO, the dog rehab and the mortgage payment both have gone well. The dog’s not totally healed and the house isn’t totally moved into, but things are quite improving on both fronts.

On the Crab front, we have a slight tweak here, as I’m going to test out issue-focused editions. Instead of three articles with three different topics, King Crab supporters get three articles with one consistent theme. As free, Blue Crab subscribers, y’all get a taste of this with one article per week that touches on our chosen topic. If that taste doesn’t sate you, you can become a King Crab Supporter here.

This week, we’re talking about diagnosing hypermobility syndromes, let’s dive in!

Is the B.S. BS?

The Gist - You know it, you love it, it’s the Beighton scale! Invented in 1973, the Beighton scale has been dominating the field of hypermobility ever since. But is this 9 item measure originally intended to assess mobility in an African population really that good? It’s fine… I guess.

What I can tell you is that inter- and intra-rater reliability are both excellent, which is great, but does it measure what we want it to measure? This paper argues that the answer is not really. At least, “The BS should not be used as the principle tool to differentiate between localised and generalised hypermobility, nor used alone to exclude the presence of [general joint hypermobility] ”. And here it’s important to point out that joint hypermobility isn’t a diagnosis and it’s not even necessarily a problem. EDS and Joint Hypermobility Syndrome, some diagnoses associated with it, are found in about 1 in 500 people (0.2%).

But back to the Beighton scale. These authors point out that there’s no gold standard for hypermobility assessment but there are alternatives (some of which I’m covering below) including the Rotes-Querol system and Hospital Del Mar criteria. The BS was originally supposed to be a screening tool and researchers and clinicians don’t agree what the cutoff for hypermobility should be. To keep the Gist a gist, I’ll close up this section by saying that it lacks correlation with lower limb and shoulder hypermobility, is correlated with spinal and hand mobility, is reliable, is unable to measure the degree of hypermobility, and has not been demonstrated to be specific or sensitive enough to include or exclude general joint hypermobility in individuals.

It’s a screening tool that need be combined with clinical judgment and other signs/criteria.

Tell Me More - I know that was already a lot, but my wife is a hypermobility specialist (she’s even on the EDS website!), so this is an important topic in our household. So let’s continue with more nuggets from this very readable and well-written paper.

Let’s talk reliability, like how joints that present “with borderline hypermobility are left open to interpretation on its scoring by different examiners or on different occasions.” Since the scale been shown to be pretty darn reliable, this isn’t a huge concern in most cases, but is thrown into relief when you consider how “hypermobility is diminished on the dominant side of the body”. There are other factors as well:

Stretching and warming up have been shown to increase joint ROM 42; while temperature, both heat and cold, have been shown to affect the flexibility of tendons and ligaments, ultimately influencing joint ROM 43, 44. In addition, hormonal fluctuations during the menstrual cycle are thought to affect laxity of the knees 45. Together, it is conceivable that an individual’s BS could be dependent on circumstantial factors at the time of examination, such as climate, temperature, stage of menstrual cycle, and prior physical activity, particularly in those with a borderline presentation.

With all this behind us (and even more in the paper) what are we to do? These authors recommend extending BS assessment with the Hospital Del Mar or Rotes-Querol systems, while you may also use the ULHAT or the LLAS (both covered below) for more details. In all of these scales, we still don’t have a ton of research on their validity and we’re just in process of making them reliable and valid tests. Overall, the authors recommend that you remember that the Beighton Scale is a screening tool. It’s not diagnostic and it’s not an outcome meaure. It takes a combination of screening tools and clinical judgment to determine hypermobility and you have to keep you eyes open, even if the BS doesn’t agree.

Can I get more details? Yupp, you can. Right here in the paper.

Want to learn more about the ULHAT, LLAS, and other Hypermobility Scales?

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And that’s it! Thank you for bearing with me through some challenging times and allowing a break when I needed it. Double thank you to everyone who checked in with me, I really appreciate it! If I didn’t respond to your email, I’m so sorry! I tried to get back to everyone, but may have missed someone. Just know that if you didn’t hear from me, it was my fault, not yours.

I hope you enjoyed Issue 100 of PT Crab and I’ll be back with 101 next week. I’ve now been doing this for over 2 years and it’s crazy. Thank you all so much for supporting this project, I really appreciate it.

Have a great week,
Luke

Here are the details on this week's article:

• Malek, S., Reinhold, E. J., & Pearce, G. S. (2021). The Beighton Score as a measure of generalised joint hypermobility. Rheumatology International, 41(10), 1707–1716. https://doi.org/10.1007/s00296-021-04832-4