The flexor and extensor tendons of the hand are equipped with special gliding mechanisms. Blood supply is provided via paratenon and in the fibro-osseous tunnel via mesotenon. The tendons show different amplitudes of active excursion which decrease distally. The function of flexors and extensors is coordinated and supplemented by reflexes and by the correlating relay system of lumbricals. Activation of extensor aponeurosis results via the so-called extrinsic and intrinsic system, where the IP joints are additionally linked functionally by the oblique retinacular ligaments of Landsmeer. At the level of the MP joint, the dorsal aponeuroses are furthermore linked by oblique fibrous structures, which lead to functional impairment of the neighboring MP joints in maximal flexion and extension of a finger due to an effect of tenodesis (so-called quadriga phenomenon).
[Anatomy of the flexor and extensor tendons] Publishing Authors By Initials
