Last edited April 10th, 2023, by David "R2DLiu" Liu

Introduction

Climbing, like most sports, is quite prone to injury. I unfortunately suffered one of the most common but catastrophic injuries a climber can suffer: the dreaded pulley rupture. I felt compelled to do a writeup on the whole process from start to finish, as well as summarize all the useful information I've accumulated over this time. I've updated this page every once in a while to continue reporting on results and my healing, which I am happy to report is more or less complete!

Pulley injuries are widely familiar amongst climbers, but the literature surrounding it is relatively sparse. The physics of the system of tendons of ligaments in the hand is complex and nonlinear. Modelling of the system is basically nonexistent. I'll attempt to piece together what I think are the most essential pieces from the last few decades of literature, but feel free to skip this section if you're mostly interested in my rehab and recovery process.

Anatomy

Pulleys are ligaments in fingers that basically form a tunnel for the flexor tendons to go through, as pictured above. Flexor tendons are connected to the muscles/bone in your forearm, and glide back and forth through the tunnel according to muscle tension. When the muscles in the forearm are contracted, the flexor tendons pull the tips of your fingers towards the arm, causing the fingers to come with them and bend accordingly. However, if the fingers encounter resistance, such as when grabbing an edge, the flexor tendons push against the pulley system, which normally holds up quite well. There are five 'annular pulleys', labelled A1-A5, and these are what we will focus on throughout this article.

Types of injury

Injuries to the pulley system are uncommon among the general population. Crowley and Zafonte note that pulley damage tends to occur in high level athletes that generate insane amounts of force on their fingers, namely professional baseball pitchers and rock climbers. Other cases are usually the result of losing control while lifting large, heavy objects or jamming a finger/hand during contact sports, such as Brazilian jiu-jitsu or American football.

Marco et al. did a study back in the 90s on stress testing the pulley system and seeing how fingers reacted under large loads. They tested 21 fingers, taken from recently deceased individuals, and loaded them into what amounted to a sophisticated torture device, applying weights to the pulley system until something broke.

The results:

• 2 fingers fractured before the pulleys ruptured (wow).
• In the remaining 19 fingers, pulleys ruptured before anything else in the fingers failed.
• The A4 ruptured first in 14 fingers. (p < 0.001)
• The A2 ruptured first in 3 fingers.
• In one finger, A3 and A4 ruptured simultaneously.
• In one finger, A2, A3, and A4 ruptured simultaneously.

Similar results are seen from rock climbing injuries, where generally the A4 and the A2 are the most commonly injured, seeing as they are the pulleys most directly responsible for finger strength and range of motion in pulling/gripping. The video below is one of the best visualizations I've seen:

Personal Injury Overview

I was first introduced to climbing around 2015 or 2016. It didn't hook me immediately, but around 2018, my college's Outsiders Club began providing free trips to our local climbing gym some Friday nights. As I began climbing more regularly, my redpoint level quickly bounced from around V2 to V6-7, without any real training or other physical activity. Once I graduated and moved to San Francisco, I was heading to Dogpatch once or twice a week. By mid 2019, I'd broken into V8ish territory, though I now consider Dogpatch setting to be relatively soft. Late 2019/early 2020 saw me move back to the east coast, get into powerlifting, learn to eat and train properly, and increase my rate of improvement. Late 2021 saw me able to start flashing V7s, crush most V8s within a session or two, and finally break into sending V9/projecting V10 territory.

Then this happened:

On November 19th, 2021, I pulled a little too hard on a V9 with small pockets and snapped the A4 pulley in the middle finger of my right hand.

Diagnosis/Prognosis

I instantly knew that I'd broken a pulley, despite having never even remotely injured one before. I felt something simply give way and then felt a slight shockwave of force, and there was no room for doubt. The breaking of the pulley itself didn't hurt much if at all. My finger almost immediately began swelling and felt numb and buzzed, similar to the way your arm might feel after hitting your funny bone. Attempting to hold anything with it resulted in nothing, as if it wasn't connected to my brain anymore. My finger lost so much range of motion and strength that I was unable to use it with my thumb to pinch the power button on my phone to turn the screen on, and had to use the index finger instead.

First order of business was to find a hand specialist and confirm the injury. While there was a distinct pop at time of injury, audible even in the video, pops don't always mean pulley ruptures. Even though I was sure in my case, it is still important to rule out other complications, like bone fractures, and see the total extent of the damage.

It's generally difficult to find doctors who understand the severity of a pulley injury for a climber. I saw three different hand surgeons, two of which had never seen a pulley injury before. Ultrasound is the gold standard and the only modality that allows viewing of the tendons in real-time [4]. I managed to procure an MRI, an X-ray, and an ultrasound viewing, and confirmed a full, isolated A4 rupture with no other damage to the hand/finger. Expected news, but still a heavy hit to morale.

Schöffl et al. was the first to write a comprehensive summary paper on finger pulley injuries back in 2006. Alongside other useful information, they categorize the severity of injuries into an easily parsable table:

Treatment

Treatment, as you might imagine, is not an incredibly well researched subject for an injury that is so uncommonly seen. The vast majority of papers on the subject comes from a few dedicated individuals who happen to be both hand surgeons and climbers, a very small overlap. Many of their ideas converge on the concept of what the papers call TPD, or tendon-phalanx distance.

Background

The job of the finger pulleys, as explained above in the video, is to hold the flexor tendon close to the bone so it can bend the fingers properly when force is exerted. Injury to the pulleys can stretch or break them, and the result is that the tendon sits further away from the bone than is normal. The distance between the tendon and the bone is what "TPD" refers to. This distance is normally very small, ranging from 0-1 mm in healthy, uninjured pulleys. In injured pulleys, as you might expect, the tendon pulls much further away, often > 4 mm.

When pulleys heal, whether the finger recovers range of motion and strength is strongly correlated with the resulting TPD. If the finger heals in such a way that the tendon stays close to the bone, generally people recover fine. Others who find loss of strength, flexibility, and range of motion often have larger TPD when measured via MRI or ultrasound. We've now set the stage for Schneeberger and Schweizers' idea, which seems intuitive and is a reasonable leap in logic from our prior research.

Pulley Rings

Schneeberger and Schweizer released some highly intuitive research on the usage of "pulley protection splints", which I'll refer to as pulley rings from here on. The idea is stunningly simple: create a tight, well fitting ring out of thermoplastic, shaped in such a way as not to limit blood flow, and wear it 24/7 for two months post injury. The ring squeezes the finger vertically, pushing the injured tendon/pulley closer to its anatomically correct position, but is shaped in such a way that it has gaps on the sides, where the arteries send blood and nutrients to the finger, so it does not inhibit blood flow. Their paper tested this idea on 47 professional/high level climbers, with this striking line in their results: "PPS treatment decreased mean ± SD TPD from 4.4 ± 1.0 mm to 2.3 ± 0.6 mm after A2 pulley rupture and from 2.9 ± 0.7 mm to 2.1 ± 0.5 mm after A4 pulley rupture.Tendon-phalanx distance was reduced in all patients. Finger range of motion (n = 42) and finger strength (n = 22) did not differ significantly between treated and contralateral sides." p values for both A4 and A2 pulleys were < 0.001. I showed this paper to my surgeon and he immediately seconded the protocol, as did V. Schöffl himself (who actually responded when I reached out to him on Instagram). This is the protocol I followed for the entirety of my healing and is what I feel is the best possible treatment one can do for a pulley injury.

If you are injured and need one of these, you can find an extraordinarily detailed guide to make one of these rings here. You can also show that page to your physical therapist and have them make one for you, depending on what is financially feasible. Another alternative is made by NiceClimbs, sold on Amazon with very fast shipping. These come in a range of sizes and are, in my opinion, very functional but pretty uncomfortable. I used them until I could make a custom one to fit my finger. A final choice is the SPOrt™, which basically comes with a kit for you to make your own ring. All are good options.

Rehab Exercises

Alongside wearing a pulley ring, I initially began with some of the protocols encouraged by the well known Esther Smith, which is detailed in an excellent article. A few weeks after injury, I also began performing blood flow restriction training, and a few weeks later, once I felt comfortable hanging from edges again, finally added on Eva Lopez's famous maximal hang training using her Transgression hangboard.

Surgery

The medical field refers to non-surgical methods of treatment as "conservative". With regard to pulley ruptures, the current literature is unable to determine whether surgical outcomes are plainly better or worse than conservative treatment. Indeed, even determining an outcome to be "good" or "bad" is highly subjective, with athletes primarily focusing on post-treatment performance, rather than long-term quality of life [4]. However, it is undebatable that invasive surgery obviously comes with a larger set of complications, such as possibility of infection, longer recovery time, potential failure and need to reoperate, etc. Bouyer et al. showed a success rate of 30/38 climbers who were able to return to or improve their previous climbing level after surgery. Schneeberger and Schweizer: 38/47 without surgery. One of the main concerns with pulley reconstruction is that it is usually done with methods that are not anatomical and can have significant side effects.

The loop technique is one of the most popular and results in great mechanical strength: on a study with a similar torture device as above, every finger fractured before the reconstructed pulley failed (citation needed). However, Jakubietz et al notes that looping techniques are somewhat heavy handed, interfering with gliding motion and potentially causing tendon adhesions. They also disagree with many of the other techniques, and discard the idea of primary repair given its instability. They perform a novel technique, with a different tendon graft, and attempt to basically replicate as close as possible the original pulley shape, material, and nature.

Jakubietz et al. reports 0 mm tendon distance after surgery and throughout the years of recovery, a marked case study success. Unfortunately, no surgeon I found was willing to perform any procedure for just a single torn A4 pulley, much less a new one from 2017 reported in a case study. The original authors themselves live in Germany, so a bit out of luck there. Currently, I have no plans to get surgery and am continuing with conservative treatment and rehab.

Timeline

• November 19th, 2021 - Pulley rupture. Swelling, but little to no pain. Tingling, numbness, and horrible weakness. Large loss of range of motion: could not make fist, finger hovered around an inch away from palm.
• November 21st, 2021 - Obtained NiceClimbs pulley rings
• November 25th, 2021 - Saw hand surgeon, and obtained MRI. Unfortunately, imaging was done with 1.5T machine, not a 3T, and quality was poor. Radiologist completely missed the pulley rupture, surgeon was more confident but was not fully conclusive November 29th, 2021 - Rested and immobilized over Thanksgiving. Began super light (feet on floor, gently stressing fingers) hangboarding. Could do a few pullups, though that didn't impact finger much. Started wearing the SPOrt™ while exercising for comfort
• November 30th, 2021 - Started rehab exercises, and began easing back into powerlifting. Heavy deadlifts are extremely difficult, though not painful, to hold *
• December 2nd, 2021 - Started BFR training. Continued to do 3-4 times a week. Very light climbing (V0 - juggy V4s)
• December 13, 2021 - Finger began feeling stiff and achy. Range of motion has increased, almost to fist. Still missing about 40 degrees ROM total. Powerlifts are back to working weights
• December 15, 2021 - Added on Eva Lopez Max Weighted Hangs. Working weight is 20 extra pounds + bodyweight = 155 lbs total on 14 mm edge for 10 seconds. Without extra weight, can hold body weight on 10 mm edge for 10 seconds. Did not have a pre-injury depth to compare to, but hazarding a guess at around 7-8 mm
• December 16, 2021 - Got a full dynamic ultrasound, and confirmed full rupture. 3.1 mm tendon distance at rest, 3.8 mm distance in flexion. Not great, especially after already a month of recovery
• December 20, 2021 - Moved up 5 lbs on Eva Lopez. Light climbing becoming easier. Able to grab some harder holds, but immediate pressure felt in finger. Playing it very careful and slow
• January 3, 2022 - Purchased a crane scale in order to more accurately track finger strength. Numbers soon. Much greater stability in finger. Crimp position still causes significant strain/pressure
• January 5, 2022 - 73.2 lbs on injured right hand on 14mm edge. 149 on left
• January 31, 2022 - 98.2 lbs on injured right hand on 14mm edges
• February 11, 2022 - Ended Eva Lopez. Strength rose steadily throughout this time. Ended on 35 extra lbs + bodyweight on a 10mm edge. Working strength around V7, V8ish. Small crimps still painful, especially if they involve more dynamic movement
• March 27, 2022 - Sent first gym V10! Pulley still nagging and achy, but not terribly painful. Holds on the V10 were all slopers and pinches.

Conclusion

By around late April, I considered myself fully healed, with both hands able to pull greater than body weight force on the 14 mm block. Currently, I can somewhat regularly climb V10. As an interesting side effect, I lost the ability to hyperextend the finger at the DIP joint where the pulley was broken, which hurts my crimp strength in that hand (approx 40lb less force than left hand in full crimp position). Range of motion is near fully recovered: I lost maybe a few degrees of range of motion in touching finger to palm, but can straighten the finger completely with no issues.

If you have any questions, comments, or suggestions, please feel free to reach out to me on on Twitter. Thanks for reading if you've made it down this far!

Citations

1. Zafonte, Brian, et al. "Flexor Pulley System: Anatomy, Injury, and Management." The Journal of Hand Surgery, vol. 39, no. 12, 2014, pp. 2525-2532.

2. Bouyer, M., et al. "Recovery of Rock Climbing Performance After Surgical Reconstruction of Finger Pulleys." The Journal of Hand Surgery (European Volume), vol. 41, no. 4, 2016, pp. 406-412.

3. Schneeberger, Micha, and Andreas Schweizer. "Pulley Ruptures in Rock Climbers: Outcome of Conservative Treatment With the Pulley-Protection Splint—A Series of 47 Cases." Wilderness & Environmental Medicine, vol. 27, no. 2, 2016, pp. 211-218.

4. Crowley, Timothy P. "The Flexor Tendon Pulley System and Rock Climbing." Journal of Hand and Microsurgery, vol. 4, no. 1, 2012, pp. 25-29.

5. Schweizer, A. "Treatment of Flexor Pulley Injury in Rock Climbers." Uniklinik Balgrist Information Sheet, 2008, pp. 1-3.

6. Lin, Gau-Tyan, et al. "Functional Anatomy of the Human Digital Flexor Pulley System." The Journal of Hand Surgery, vol. 14A, no. 6, 1989, pp. 949-956.

7. Jakubietz, Michael G., et al. "Acute A4 Pulley Reconstruction with a First Extensor Compartment Onlay Graft." Plastic and Reconstructive Surgery Global Open, vol. 5, no. 6, 2017, pp. e1361.

8. Schöffl V, Hochholzer T, Winkelmann HP, Strecker W. Pulley injuries in rock climbers. Wilderness Environ Med. 2003;14(2):94-100. doi:10.1580/1080-6032(2003)014[0094:piirc]2.0.co;2

9. Marco RA, Sharkey NA, Smith TS, Zissimos AG. Pathomechanics of closed rupture of the flexor tendon pulleys in rock climbers J Bone Joint Surg Am 1998801012–9.(Erratum in 1999;81:439.)