Avoid Finger Blowouts

By Guillaume Michaud, M.D./Illustration by Jamie Givens

Taping to support finger tendons can help prevent injury, but studies show the most commonly used taping method doesn’t do the job. Here’s a better way.

There are two main flexor tendons in each finger: one that flexes the middle phalanx, and one that flexes the fingertip. These tendons are supported by a system of ligament-like “pulleys” that hold the tendons close to the finger bones and give them the mechanical advantage needed to flex the fingers.

A ruptured pulley—caused by too much force on the tendons—results in “bowstringing” of the tendon. Before 1980, almost no cases of pulley rupture resulting from sports were found in the orthopedic literature, but cases are now seen each year in the U.S., mostly among rock climbers. Of the five main pulleys, the A2, A3, and A4 are the most important because they are strategically placed around the second fi nger joint where pulley-rupturing forces are greatest. The goal of any taping method is to support and protect those pulleys.

Pulleys are strong, so you’re only likely to rupture one during an uncontrolled contraction— e.g., when popping off a foothold. The middle and ring fingers are the ones most commonly injured. Crimping is particularly conducive to injury. Studies show that the stress applied to the A2 pulley in the crimping position is about 36 times greater than in the open-hand hanging position, and three times greater than the force applied to the tip of the f nger.

The commonly used circular taping of the first phalanx, which supports only the A2 pulley, has been studied in the lab, and no difference was found between taped and untaped fingers. Try the method illustrated here, which supports all three main pulleys at the same time.

With one continuous strand of tape, complete two or three turns around the first phalanx. Don’t tape too tightly! There’s a nerve and an artery at each side of the finger, and you don’t want to pinch them. Then cross over the joint, and complete two or three turns around the second phalanx. Finally, cross back over the articulation to the first phalanx, forming an “X,” and complete a final circular wrap to secure the tape.

If done well, this taping method doesn’t interfere with the flexion of the finger and also offers some protection to the skin— useful when climbing thin cracks.

Dr. Guillaume Michaud, 27, is a climber and senior resident in orthopedic surgery at University of Sherbrooke, Québec.