The functional significance of the oblique retinacular ligament of Landsmeer. A review and new proposals.

The author presents a review of the current ideas of the function of the oblique retinacular ligament, first introduced by Landsmeer. It was suggested that the oblique ligament plays an important role in synchronizing the movements of the two distal phalanges and that it initiates extension of the maximally flexed distal phalanx. The author raises some objections to these ideas, referring partly to experiments performed by Harris and partly to some experiments reported in the present paper. These experiments disclosed that extension of the maximally flexed distal phalanges was actively initiated by motor forces. The author proposes another function of the oblique retinacular ligament, i.e. as a restraining and thus stabilizing force of the flexed terminal phalanx when the fingertip is used for pressure while the proximal interphalangeal joint is forced into full extension.