The gliding characteristics of the flexor pollicis longus tendon in the carpal tunnel: potential implications for manual pipette users.

To understand the potential mechanism for hand and wrist complaints in pipette users, whose motion is characterized by repetitive thumb motion in certain wrist positions, the peak (PGR) and mean (MGR) gliding resistance of the flexor pollicis longus (FPL) tendon were measured in nine human cadaver wrists. The PGR with the wrist in 30° ulnar deviation and in the neutral position were significantly lower than the PGR with the wrist in 60° flexion. The MGR with the wrist in 30° ulnar deviation was significantly lower than the MGR with the wrist in 60° flexion, 60° extension, or 20° radial deviation with 40° extension. Based on these data, we believe that a manual pipette designed to be used in neutral to ulnar deviated wrist position could have ergonomic advantages.