Research > Technology Reviews > Using a “pulley splint” to support your finger

The Pulley Splint: A Review of the Swiss and American Products

UPDATE on the switch of the term “pulley protection brace” to “pulley splint”: The original term used in the Schneeberger and Schweizer (2014) article is a “Pulley Protection Splint.” The term used in the Algar and Moschetto (2017) article is a “pulley protection orthosis.” Dr. Warme refers to it as both an “orthosis” and a “splint.” In order to be consistent with all sets of authors I have decided to remove the term “protection” and replace “brace” with “splint.” In an e-mail discussion with Dr. Warme, he makes a good point that these devices should not necessarily be thrown on just to put in more attempts on a project (more attempts may increase the risk of a repetitive stress injury). In an e-mail from Dr. Schweizer, he agreed that “the ring is not intended as a prophylactic tool to prevent a pulley disruption in an asymptomatic climber,” and that the word “protection” was originally meant to “protect the healing pulley,” not to protect it against injury in the first place. He acknowledged the context of the word “protection” in English may be different than in his native language and thus agrees with a switch in the name. All changes have been made — however, I’ve decided to keep the same URL to avoid broken links.

I’m going to summarize very briefly the most practical information I’ve found regarding a device called a “pulley splint.”  For more in-depth information into this and other injury-related information, I encourage you to visit the injury section of the Beta Angel Research Inventory. Note: see the end for some practical prevention advice as well tips for how to make the splints!

A slightly ridiculous oversimplification to get you caught up

Pulley’s are little tendons which wrap around each of your finger bones at 5 different locations.  Their purpose is to keep the tendon which flexes (long flexor tendon) your finger from “bowstringing” or separating from the bone.  Unfortunately, as your flexor tendon shortens, it has a habit of creating something like a “sawing” motion against your pulleys, which has the potential to create little micro-tears.  Due to the biomechanics of your finger while crimping, these tears primarily occur in the A2 and A4 pulley. 

Why is bowstringing an indication that something is wrong?

Researchers measure bone-to-tendon distance and use it as an indicator that something is wrong because more bowstringing leads to a reduced ability to flex the finger.

The “pulley ring” – The Swiss research

3-D Printing Template for Andi’s splint

Dr. Andreas Schweizer is considered to be one of the top pulley specialists in the world.  He developed a “pulley ring” which helps keep bowstringing to a minimum by compressing the tendon toward the bone.  This effect takes strain off the pulley while scar tissue forms.  Dr. Schweizer’s 2016 study on 47 climbers with single pulley ruptures had very positive results both for the bone-to-tendon distance and return to previous climbing grade.[1]

View from the insider of the finger with the pulley splint on the outside

By placing the pulley ring at the edge of the pulley but before the appropriate joint, bowstringing was reduced by 50% and 40% in the A2 and A4 pulleys respectively. [2]   The pulley ring has openings on either side in order to avoid compressing “neuro-vascular bundles”, which are needed for circulation.  Because he’s a doctor, Andi’s splint is for rehabilitation, not prevention.  However, an American version exists of a different flavor.   

The SPOrt™ – The American Approach

Dr. Winston Warme is in the Department of Orthopaedics and Sports Medicine at the University of Washington.  Assuming no pain, the maker of the SPOrt™ suggests it can be used while climbing and even training.  The device is structured differently from Dr. Schweizer’s, in that the opening is placed on the back of the finger, rather than the side.  Additionally, it appears to be worn slightly back (toward the knuckles), in comparison.  Finally, Dr. Warme appears [UPDATE: Dr. Warme has sent me an e-mail noting that the SPOrt™ works for both the A2 and the A4!] to recommend his for the A2 [and A4] pulleys.  Due to the distinctions between the two splints, it’s challenging to make effectiveness comparisons.  However, Dr. Warme has a research paper involving 20 rock climbers currently undergoing peer review.  You can find the SPOrt™ at Dr. Warme’s website: ROCKNSPORT.

UPDATE: Additional information from Dr. Warme — because medical evaluations can be expensive and take time, Dr. Warme believes in providing the splint quickly and efficiently to the general public. In his view, timeliness will make the greatest impact, both in the case of acute injuries as well as chronic injuries or finger tendonitis. And if fingers are getting sore, he highly recommends rest and working on other types of training.

When should you use a pulley splint?

The research trial was used on climbers with a single A2 or A4 pulley rupture.  Additionally, a conference paper at the 2018 Chamonix Research conference highlights good initial results from treating multiple pulley ruptures with two pulley splints.[3] Dr. Warme’s website recommends his splint can be used for soreness at the base of the finger on the palm side, complete A2 pulley ruptures, partial A2 pulley injuries (chronic or acute), and returning to climbing after an A2 reconstruction surgery, as well as the management of similar A4 injuries.  Both Dr. Schweizer and Dr. Warme recommend working with a physical therapist.  Dr. Schweizer has a series of recommendations involving the splint, tape, and movement exercises. You can download his recommendations below:

UPDATE: I like to let readers know when I identify healthy points of debate. In the above treatment plan from Dr. Schweizer, the splint is removed between weeks 8 and 12 and tape is applied in order to reduce flexion of the middle joint up to 80°. Dr. Warme’s view is that tape is not strong enough to “resist a deforming load” and greater levels of tightness will cut off circulation. Dr. Schweizer “absolutely agrees” with Dr. Warme’s conclusion that “any device, including tape” will not prevent a pulley rupture, and says that the cadaver studies he’s performed confirm this. Additionally – Dr. Schweizer states that while he’s “not a friend” of taping”, that there may be benefit during the “late phase of pulley healing” if there is still apparent bowstringing, with some benefit of reducing range-of-motion of the finger. In Dr. Warme’s view, replace the tape with the splint. In Dr. Schweizer’s view, use tape with the splint and then tape once the splint is removed if there is still apparent bowstringing and to decrease range-of-motion. I’ll update this section if I hear back from either Doctor.

Practical advice for practical people

If you’re in the United States and already injured, you can go to Dr. Warme’s website and purchase your “kit.”  However, since he markets his device only for the A2 [update: or A4 pulley injuries. Good news if you live abroad, RocknSPOrt ships the SPOrt™ kits internationally at no extra change].  With the 3D Model and Dr. Schweizer’s treatment plan, which he sent me, it’s possible for Physical Therapists in the United States who are familiar with working with thermoplastic material (note: see update below) to construct them and follow a directed plan.

UPDATE: Dr. Jared Vagy (lecturer at USC and author of “Climb Injury-Free”) sent me a very useful ‘how to make a CUSTOM pulley splint’ video, write-up, and price breakdown. Check out the great tutorial at his website.

If you’re not injured, here’s some prevention advice: one of Dr. Schweizer’s research studies found that it takes 100-120 progressively difficult moves to properly warm-up the pulleys.[4][5]  How did they define “proper?” By looking at the relationship between grabbing holds and the distance to the bone of your long flexor tendon using a device that measures physical pressure and converts it into an electrical signal.  Andi recommends 3-4 routes with 40 moves or 8-12 boulder problems of progressive difficulty.[6]

Graphic from one of Dr. Schweizer’s research papers: “Sport Climbing from a Medical Point of View,” Published in Swiss Medical Weekly (2012), 142:w13688.

[1] M. Schneeberger, A. Schweizer, “Pulley Ruptures in Rock Climbers: Outcome of Conservative Treatment With the Pulley Protection Splint – A Series of 47 Cases,” Wilderness Environmental Medicine, June 2016, Vol. 27:2, 211-218

[2] A. Schweizer, “Sport Climbing from a Medical Point of View,” Published in Swiss Medical Weekly (2012), 142:w13688

[3] A. Schweizer, “Conservative Treatment of Triple Finger Flexor Pulley Disruption,” Conference Paper from the International Rock Climbing Research Association’s 2018 conference in Chamonix, France.

[4] A. Schweizer, “Treatment of Flexor Pulley Injury in Rock Climbers”

[5] Schweizer A. Biomechanical properties of the crimp grip position in

rock climbers. J Biomech. 2001;34:217–23.

[6] Ibid “Treatment”