An isolated closed injury of the finger flexor pulley system (FFPS) is the most common upper extremity injury in rock climbers followed by flexor tenosynovitis (1).The FFPS system consists of a series of tunnels which the tendons of flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) course to the tip and middle part of the fingers respectively. The tunnels in which the FDP and FDS tendons travel under are created by the flexor synovial sheath and the associated localized thickenings which include five annular pulleys and three cruciate pulleys (2). The most commonly injured are the A2 and A4 pulley of the ring finger during a ‘crimp’ position. The ‘crimp’ position requires the FDP/FDS tendons to sharply change direction at the proximal interphalangeal joint (PIP) while exerting force on the distal fingertips. This predisposes the flexor tendons to want to sublux volarly (“bowstring”) and thus stresses the respective pulleys (3).
A FFPS injury can be the result of an acute (shock-loading) or chronic (repetitive stress) related mechanism as result of the sport’s unique biomechanical demands placed on the fingers, with most acute onsets (~60%) occurring in the sub-discipline of bouldering (1). Climbers will most commonly report hearing a popping sound followed by an onset of sudden pain and swelling over the affected area. Subsequent numbness and local hematoma formation may also present. Clinical bowstringing upon physical examination and history of audible ‘pop’ may not predict the grade of FPPS injury (2).
The grading of FFPS injuries exists on a I-IV scale based on the severity and specific pulleys injured. Ultrasound imaging is considered the gold standard for evaluating pulley integrity and the degree of flexor tendon bowstringing. The majority of FFPS injuries (GI-III) are managed conservatively with hand physiotherapy and a gradual return to climbing program. Due to the complexity and interrelationship of the anatomical structures of the fingers, FFPS injuries can be difficult to manage and rehabilitate.
Reach’s combination of sports physiotherapists and certified hand therapists in Edmonton offers the expertise you need to get back on the wall safely. If you are a climber suffering from a finger-related injury and unsure if this is what you need, give us call and we can guide you towards the best path for your needs.
1. Lutter C, Tischer T, Hotfield T, Frank L, Enz A, Simon M, et al. Current Trends in Sport Climbing Injuries after the Inclusion into the Olympic Program. Analysis of 633 Injuries within the years 2017/18. Muscle Ligaments Tendons J. 2020 Jun;10(02):201.