Static and dynamic human flexor tendon–pulley interaction

Proximal phalanx flexor tendon tenodesis after severe frostbite in a rock climber

A 32 year-old climber sustained a grade IV frostbite injury to the right hand which required amputation at the neck of the proximal phalanges of all the long fingers. To increase range of motion and strength in the remaining metacarpophalangeal joints, tenodesis of the flexor digitalis superficialis and profundus tendons onto the proximal phalanges was performed. Several revisions for removal of bony spurs, dorsal skin advancement flaps and web space deepening were necessary. After 2 years, the patient achieved 10-0-100° metacarpophalangeal joint range of motion in extension-flexion and could do full body-weight pull-ups on 1 cm deep holds, lift 50 kg on a 2 cm deep hold (normal contralateral side, 40 kg), climb up to F7a routes and use a mechanical 4-finger functional prosthesis.

Motion Analysis of the Wrist and Finger Joints in Sport Climbing

Climbing is a fast-growing sport, with one of the most common injuries being a rupture of the finger flexor tendon pulley. The strain on pulleys increases as finger joints flex. However, to our knowledge, no study has conducted a kinematic analysis of climbers' fingers. Thus, this study aimed to examine finger kinematics during typical climbing tasks. Eleven elite climbers performed a sequence of four climbing moves, which were recorded by an optical motion capture system. Participants used crimp, half-crimp, and open-hand grips for three trials each, with the fourth condition involving campusing using any grip except crimp. Mean proximal interphalangeal joint (PIP) flexion during the holding phase was 87° (SD 12°), 70° (14°) and 39° (27°) for the crimp, half-crimp and open-hand grip, respectively. Hence, inter-individual PIP flexion ranges overlap between different gripping conditions. Two different movement patterns emerged in the open-hand grip, possibly influenced by the use of the little finger, leading to varying degrees of flexion in the middle and ring fingers. Avoiding little finger usage in the open-hand grip may reduce load during pulley rupture rehabilitation. The implications of PIP joint angle variability on individual pulley injury risk or prevention warrant further investigation. Motion capture proved effective for understanding finger kinematics during climbing and could guide future studies on pulley injury risk factors.

Kinetics of crimp and slope grip in rock climbing

The aim was to investigate differences of the kinetics of the crimp and the slope grip used in rock climbing. Nine cadaver fingers were prepared and fixated with the proximal phalanx in a frame. The superficial (FDS) and deep (FDP) flexor tendons were loaded selectively and together with 40 N in the crimp grip (PIP joint flexed 90°/DIP joint hyperextended) and the slope grip position (<25° flexed/50° flexed respectively). Five different grip sizes were tested and the flexion force which was generated to the grip was measured. In the crimp grip the FDP generated more flexion force in small sized holds whereas the FDS generated more force in the larger holds. During the slope grip the FDP was more effective than the FDS. While both tendons were loaded, the flexion force was always greater during crimp grip compared with the slope grip. The FDP seems to be most important for very small holds using the crimp grip but also during slope grip holds whereas the FDS is more important for larger flat holds.