Training for Climbing, 2nd: The Definitive Guide to Improving Your Performance (How To Climb Series)

surprise that they are the most common site of injury. Unfortunately, these pesky finger injuries are often hard to diagnose precisely and, worse yet, in the early stages tend to be ignored. Many climbers rationalize that they can climb through one injured finger, since they have nine healthy fingers and can still manage to crank at a near-maximum level. Continued climbing on an injured finger may increase the severity of the injury, however, and thus double or triple (or more) the downtime needed to recover.
    Understanding the most common injuries requires some knowledge of hand anatomy (see figure 11.3). To begin with, there are no muscles in the fingers. Flexion of the fingers and wrist is produced by the muscles of the forearm that originate from the medial (inside) elbow and terminate via long tendons that attach to the middle phalanx (MP) and distal phalanx (DP) of each finger. The flexor digitorum superficialis (FDS) muscle inserts into the palm side of the MP and produces flexion of the proximal interphalangeal (PIP) joint. The long tendon of the flexor digitorum profundus (FDP) muscle passes through a split in the FDS and then inserts on the palm side of the DP. The FDP controls flexion of the distal interphalangeal joint (DIP).

     
    Figure 11.4 Annular Pulley Injuries
     

    Both flexor tendons (FDS and FDP) pass through a tunnel-like, synovia-lined tendon sheath that provides nourishment and lubrication. The flexor tendon and sheath are held close to the bone by five annular pulleys (A1, A2, and so forth) and three (sometimes four) cruciform pulleys that prevent tendon “bowstringing” during flexion. Biomechanical studies have shown that the A2 and A4 pulleys are the most important (Lin 1989). As a conceptual model, visualize the whole system of the flexor tendon, sheath, and annular pulley as functioning like a brake cable on a bike.
TENDON PULLEY INJURIES
     
    The most common finger injuries experienced by climbers involve partial tears or complete ruptures of one or more of the flexor tendon annular pulleys. In many cases only a partial tear of a single pulley occurs; in more serious incidences, however, one or more pulleys may rupture entirely, resulting in palpable or visible bowstringing, respectively. The exact nature and extent of the injury is difficult to diagnose without use of magnetic resonance imaging (Gabl 1996), though a recent Austrian study has shown Dynamic Ultrasonography to be highly effective at depicting finger pulley injuries in rock climbers as well (Klauser 2002).
    The A2 pulley is the most commonly injured of the five annular pulleys, and you can blame the common crimp grip as the main culprit. In using the crimp grip, near-ninety-degree flexion of the PIP joint produces tremendous force load on the A2 pulley, in addition to forceful hyperextension of the DIP joint. Injuries to the A2 pulley can range from microscopic to partial tears and, in the worst case, a complete rupture (see figure 11.4). Small partial tears are generally insidious, because they develop over the course of a few climbs, a few days of climbing, or even gradually during the course of a climbing season. Less frequent are acute ruptures that result during a maximum move on a tiny crimp hold or one-finger pocket. Some climbers report feeling or hearing a pop —a likely sign of a significant partial tear or complete rupture—though other injuries could also produce this effect.
    Depending on the severity of an A2 pulley injury, pain and swelling at the base of the finger can range from slight to so debilitating that you can’t perform everyday tasks like picking up a jug of milk. Swelling may limit the range of motion during flexion, and bowstringing may be felt or seen (Marco 1998) if one or two additional pulleys (usually A3 and A4) are ruptured, respectively. Slight tears may be asymptomatic when the finger is at rest, but become painful during isometric contraction (as in gripping a hold) or when pressing on the base of the finger near the top of the palm.
    Treatment of an A2 pulley injury must begin with completed cessation of climbing and discontinuation of any other activity that requires forceful flexion of the injured finger. Doing anything that causes pain will slow healing of the injured tissue and may even make the injury worse. Therefore, the intelligent climber will cease climbing at the very moment of the injury so that the healing process may begin and the time frame for healing is most