INmotion Magazine interviews The University of Southern California's professor Dr. Jared Vagy DPT. The article discusses the physical demands of rock climbing and Dr. Vagy's unique approach to assessing and treating rock climbers.
Vogue magazine published an interesting piece in their fitness section on rock climbing. The Climbing Doctor was quoted in the article saying "There are over 30 muscles in the hand, wrist and fingers alone," explains Jared Vagy - a Los Angeles based physical therapist who specializes in climber "These are essential to grip onto smaller holds."
The tendons in your fingers are anchored down by pulleys that keep the tendons gliding flush to the bones. Excessive strain on the finger can exerts an outward force on the pulley which may strain or tear it.