33% OF CLIMBING INJURIES ARE THE SAME. WHY? - My Response to Kyle Hill's Viral Video
Hooper’s Beta Ep. 109
INTRODUCTION
The Video: 33% of climbing injuries are the same. Why?
As requested by a subscriber, we’re going to review and critique Kyle Hill’s viral video “33% of climbing injuries are the same. Why?”, which definitely piqued my interest as a physical therapist.
I had actually seen this video a few months ago when it was titled “The Dangerous Physics of Rock Climbing,” and I’ve got a lot to say about it so this should be fun.
01:15 “It’s not that I don’t know what I’m doing…[lists credentials].”
I totally understand Kyle’s frustration here and I think this part of the video actually highlights the reason Emile and I started Hooper’s Beta in the first place: Kyle’s been involved in climbing for 15 years and yet he hasn’t encountered any solution or explanation for why he’s getting injured.
I think most of us at some point have had that experience of feeling totally in the dark about an injury and worrying we won’t find a solution, or, even worse, getting misinformation from other people and putting ourselves at risk. Climbing is still such a new sport when it comes to training and rehab data, so quality advice is just not always easy to come by.
It’s unfortunate this appears to have been Kyle’s experience, but luckily new information is slowly becoming integrated into the climbing community’s general pool of knowledge.
If you want to speed up that process and help us reach our goal of creating the largest online library of free information for climbers, like this video and consider sharing it so people like Kyle can see it too!
02:12 “...the crimp, which can be open or closed.”
I think he’s just trying to keep things simple here for his non-climber audience, but there are several ways to grip a crimp hold including a draped or dragged position, a half crimp, a closed crimp, a full crimp… with each position changing the way our fingers handle force. This is important for understanding the way our fingers can get injured. For example, all positions rely heavily on the FDP tendon, but the half crimp places more load on the A2 pulley than the drag. For that reason, we need to be specific when discussing crimping and crimping-related injuries.
2:38: “...crimping leads to a specific injury called a ‘pulley rupture.’”
Ah, okay, now we know what injury he’s been talking about. When he said:
he was talking about the infamous A2 pulley rupture! Pulleys are the ligament sheaths that hold your flexor tendon close to the bone in your fingers.
While that is a pretty well-known injury for climbers and something I’ve seen numerous times in my practice, I’m a little suspicious of Kyle’s claim here.
There’s no citation in the video description, but I did a bit of digging before filming this episode and found an article called “Acute hand and wrist injuries in experienced rock climbers,” which states, “Finger tendon injuries were the most common (33% of the total number of injuries)...”
I couldn’t find any other research that backed up Kyle’s claim, so I believe this is the study he was referencing. However, if we keep reading that sentence, we find something interesting.
“Finger tendon injuries were the most common (33% of the total number of injuries), which included non-specified finger tendon injuries (25%) and those diagnosed with specific A2 pulley ruptures (8%).”
So 33% of the reported injuries were in the fingers, but only 8% were specifically diagnosed A2 pulley injuries. Of course, some of the “non-specified finger tendon injuries” could have been A2 injuries that were just never diagnosed, but it certainly seems like the number is less than 33%.
Keep in mind that the data used in this study does not necessarily reflect the climbing population as a whole, as it was a survey of 545 climbers who may or may not have reported an accurate diagnosis of their injury.
Diagnosis accuracy can greatly affect these kinds of studies. Some possible evidence for this can be seen in a different study, where pulley injuries accounted for 49.4% of finger injuries (not all injuries) from 1998-2001 and just 29.5% from 2009-2012. Why the big drop? Maybe because people have gotten a lot better at differentiating between pulley injuries from other kinds of finger injuries as the knowledge has progressed.
Regardless, all the research I could find on this subject says that A2 pulley injuries make up significantly less than 33% of all climbing injuries.
Why does any of that matter? Why do I care if the number is 33% or 90% or 5%? Because I don’t want to create undue fear in climbers and because accurate diagnosis is essential for overcoming injuries. If we go around thinking every time we have finger pain it must be an A2 rupture, that bias could cause us to ignore other potential causes. In that case, we could easily end up doing the wrong rehab protocol and ultimately working against ourselves.
Overall, the lesson here is to make sure you read research thoroughly and realize your own biases can cause you to misinterpret information from time to time.
05:24 “...three [pulleys] per finger…”
Kyle must have seen some unclear or misleading information for this one. Our fingers have five annular pulleys and 3-4 (depending on what source you look at) cruciform pulleys. The number and placement of tape strips in his demonstration is inaccurate, but his explanation of how the pulleys work is great!
05:32 “There is a lot of climbing literature.”
Hah, I have to disagree there, though I wish that were true! We need much more climbing research! :)
05:50 “In the closed-crimp position, [the A2 pulley] is routinely asked to take at least 450N…”
I really appreciate that Kyle wanted to provide research-based evidence for A2 pulley failure; we need more of that in the climbing world! Unfortunately I think he made a few mistakes when interpreting the research. As a result, the way he words this part of the video actually makes it a self-defeating argument -- it disproves itself.
He says that our pulleys can handle 380-400 N, but then says the A2 is “routinely” subjected to much more than that during a closed crimp. Well, if that were the case, anyone using the closed crimp would rupture their A2 pulleys all the time! We don’t need research to tell us that is not what we actually observe in the real world, so we can conclude that at least part of his argument is incorrect. But which part? And is it actually Kyle’s fault?
If we look at the research he’s likely referring to…
… we quickly see the first error.
The study states, “... a 70 kg climber using a one finger crimp may come to support 450 N with a single finger, exceeding the maximum tolerable load, which for an A2 pulley ranges from 380-400 N [1].”
Did you catch that? A one-finger crimp!
I don’t know about you, but I don’t see people routinely crimping with one finger, especially in a closed crimp position. Generally, we’re crimping with three or four fingers so the load does not go to just one finger, which is partly why we don’t constantly exceed the threshold of our pulleys.
So that’s one reason Kyle’s argument here is not quite right. However, there’s actually a larger, much more significant problem we need to address: the research itself.
There are actually several articles that mention the A2 pulley failure point being around 400 N; in fact, we even mention that number ourselves in our Mega A2 Pulley Rehab video. However, like Kyle, we should have dug deeper. Those studies didn’t come up with that data themselves -- they’re all referencing an older study that used cadavers, aka dead people, for their measurements. They didn’t specify the age of the cadavers, but another similar study did and the average age was 75.5 years old!
I think it’s safe to assume that those A2 measurements probably aren’t that applicable to younger, active climbers. In fact, a 2001 article from Schweizer notes that pulleys in vivo are likely “...much stronger than the pulleys of aged and cadaver fingers…” in those studies.
Age plays a huge role in how durable tissues are and, more importantly, it is well demonstrated that tissues adapt over time to the demands they encounter. In the actual article Kyle references, the authors postulate the load on climbers’ pulleys could actually be around 800-1000 N!
Constantly subjecting our fingers to the high stresses of climbing actually causes physiological changes that allow them to cope. Klauser et al. showed that the A2 pulleys of climbers are 50% thicker than non-climbers, and the middle phalanx of climbers was 100-150% thicker! Even our bones can adapt! [10]
In summary, we are decidedly not exceeding the limit of our pulleys on a routine basis.
Pulley injuries do happen, but they are a result of a traumatic event or overuse. If you’d like to learn more about what causes pulley injuries and what to do about them, I’ll put a link to our in-depth A2 pulley video in the description.
06:40 - “Based upon what we know about how fingers move, it’s unavoidable.”
We’ll get to that later but I hope at this point you’re thinking hmmm, maybe that’s not correct!
07:21 “[The pulley injury] took me a year to get over.”
In my experience as a working PT it generally should not take this long to recover from a pulley injury unless the patient is not following a good rehab plan or is continuously exacerbating the issue. So if that’s your experience, all the more reason to seek help from a professional!
08:47 “And if you are a climber yourself, I do have some advice…”
The first three pieces of advice he gives are great! The taping part… highly debatable. But rather than go down another research rabbit hole, let’s finish things off with the advice I would give someone in Kyle’s position.
Pay attention to your climbing technique. Are you full crimping all the time? This is a risky habit some climbers get into early on, often to make up for weakness in other grip positions. This could increase your risk of pulley injury, so train yourself to be strong in half crimp, draped, and open handed positions and don’t rely on the full crimp as a crutch.
Measure and assess your objective fitness stats. By measuring things like finger, shoulder, and pull-up strength, you can get a sense of your current fitness level.
Track your training consistently; keep taking measurements over time. This will allow you to monitor your volume, identify trends, assess strengths and weaknesses, see your progress objectively, determine what works best for you, and even detect if you’re at risk of injury.
Have planned deload or rest weeks! Give your body a chance to heal. You don’t need to push 100% of the time.
Exercise patience. The body takes time to adapt, but it will adapt if you’re smart with your training! Rushing will only make you go backwards.
If you’re unsure about how to do any of this, reach out to a skilled professional with climbing experience. Don’t rely on gym hearsay to guide you.
Subscribe to Hooper’s Beta for in-depth science-based training and rehab videos!
OUTRO
Special thanks to Kyle Hill for the time he put into making his video; hopefully he doesn’t hate us. If you have a video you’re curious about, or that you think needs a science review, tell us about it! Until next time: train, climb, send, repeat….and read that research thoroughly ;).
// RESEARCH CITATIONS
Logan AJ, Makwana N, Mason G, Dias J. Acute hand and wrist injuries in experienced rock climbers. Br J Sports Med. 2004 Oct;38(5):545-8. doi: 10.1136/bjsm.2002.003558. PMID: 15388536; PMCID: PMC1724952.
Schöffl V, Popp D, Küpper T, Schöffl I. Injury trends in rock climbers: evaluation of a case series of 911 injuries between 2009 and 2012. Wilderness Environ Med. 2015 Mar;26(1):62-7. doi: 10.1016/j.wem.2014.08.013. PMID: 25712297.
McDonald JW, Henrie AM, Teramoto M, Medina E, Willick SE. Descriptive Epidemiology, Medical Evaluation, and Outcomes of Rock Climbing Injuries. Wilderness Environ Med. 2017 Sep;28(3):185-196. doi: 10.1016/j.wem.2017.05.001. Epub 2017 Jul 26. PMID: 28755819.
Miro PH, vanSonnenberg E, Sabb DM, Schöffl V. Finger Flexor Pulley Injuries in Rock Climbers. Wilderness Environ Med. 2021 Jun;32(2):247-258. doi: 10.1016/j.wem.2021.01.011. Epub 2021 May 6. PMID: 33966972.
Schweizer, Andreas. (2009). Biomechanics of the interaction of finger flexor tendons and pulleys in rock climbing. Sports Technology. 1. 249 - 256. 10.1002/jst.68.
Schöffl I, Oppelt K, Jüngert J, Schweizer A, Neuhuber W, Schöffl V. The influence of the crimp and slope grip position on the finger pulley system. J Biomech. 2009 Sep 18;42(13):2183-7. doi: 10.1016/j.jbiomech.2009.04.049. Epub 2009 Aug 7. PMID: 19665129.
Lin GT, Cooney WP, Amadio PC, An KN. Mechanical properties of human pulleys. J Hand Surg Br. 1990 Nov;15(4):429-34. doi: 10.1016/0266-7681(90)90085-i. PMID: 2269832.
Iruretagoiena-Urbieta X, De la Fuente-Ortiz de Zarate J, Blasi M, Obradó-Carriedo F, Ormazabal-Aristegi A, Rodríguez-López ES. Grip Force Measurement as a Complement to High-Resolution Ultrasound in the Diagnosis and Follow-Up of A2 and A4 Finger Pulley Injuries. Diagnostics (Basel). 2020;10(4):206. Published 2020 Apr 8. doi:10.3390/diagnostics10040206
King EA, Lien JR. Flexor Tendon Pulley Injuries in Rock Climbers. Hand Clin. 2017 Feb;33(1):141-148. doi: 10.1016/j.hcl.2016.08.006. PMID: 27886830. [9]
Klauser A, Frauscher F, Bodner G, et al. Stellenwert der hochauflösenden Sonographie in der Abklärung von Fingerbeschwerden bei Extremsportkletterern [Value of high-resolution ultrasound in the evaluation of finger injuries in extreme sport climbers]. Ultraschall Med. 2000;21(2):73-78. doi:10.1055/s-2000-316 [10]
Schweizer A. Biomechanical properties of the crimp grip position in rock climbers. J Biomech. 2001;34(2):217-223. doi:10.1016/s0021-9290(00)00184-6 [11]
Disclaimer:
As always, exercises are to be performed assuming your own risk and should not be done if you feel you are at risk for injury. See a medical professional if you have concerns before starting new exercises.
Written and Presented by Jason Hooper, PT, DPT, OCS, SCS, CAFS
IG: @hoopersbetaofficial
Filming and Editing by Emile Modesitt
www.emilemodesitt.com
IG: @emile166