Flexor tendon excursions in "no-man's land".

The excursions of the digital flexor tendons have been measured relative to the sheath and to one another at a point in no-man's land over the proximal phalanx, in fresh cadavers. Passive metacarpo-phalangeal joint movement produces relative motion. Distal interphalangeal joint motion produces excursion of Flexor Digitorum Profundus on Flexor Digitorum Superficialis (a mean of 1 mm for ten degrees of flexion in the index finger). Proximal interphalangeal joint motion produces excursion of the Flexor Digitorum Superficialis and Flexor Digitorum Profundus together relative to the sheath (1.3 mm for ten degrees of joint flexion in the index finger). The significance of these measurements is discussed in relation to the exploration of tendon injuries, the mechanism of failure after tendon repair, dynamic mobilisation and the anatomy of no-man's land.