Lung Brandon E., Burns Bracken
Stony Brook University Hospital
East Tennessee State University (ETSU)
The flexor digitorum profundus (FDP) is an extrinsic hand muscle that flexes the metacarpophalangeal (MCP) and distal interphalangeal (DIP) joints of the medial 4 fingers. This muscle originates from the upper three-fourths of the volar and medial surfaces of the ulna, interosseous membrane, and deep forearm fascia. The FDP lies in the deep volar forearm compartment (see . Deep External Hand Flexors). The FDP tendons insert on the bases of the medial 4 distal phalanges, deep to the flexor digitorum superficialis (FDS) tendons. The medial 3 FDP tendons are partially attached as they pass through the carpal tunnel. The FDP tendon of the index finger separates from its medial 3 counterparts proximal to the flexor retinaculum. Since the FDP tendons arise at or distal to the wrist joint, muscle contraction produces mass action movement in all 4 tendons and allows for a power grip.
指深屈肌（FDP）是一块手部外在肌，可使内侧4指的掌指关节（MCP）和远侧指间关节（DIP）屈曲。该肌起自尺骨掌侧面和内侧面上部的3/4、骨间膜及前臂深筋膜。指深屈肌位于前臂掌侧深层（见“手部深层外在屈肌”）。指深屈肌腱附着于内侧4个远节指骨的基部，位于指浅屈肌（FDS）腱的深面。内侧3条指深屈肌腱在通过腕管时部分附着。示指指深屈肌腱在屈肌支持带近端与其内侧3条肌腱分离。由于指深屈肌腱起于腕关节或其远侧，肌肉收缩可使所有4条肌腱产生整体运动，并实现强力抓握。
