Flexor Digitorum Superficialis

The superficial layer of volar muscles consists of the flexor digitorum superficialis, the pronator teres, the palmaris longus, the flexor carpi radialis and the flexor carpi ulnaris (Fig. 9.2b,c). These muscles take their origin from a strong common tendon which arises from the medial epicondyle (see Chapter 8). The flexor digitorum superficialis, the largest muscle of the superficial layer, consists of three heads - humeral, ulnar and radial - which join at the proximal forearm and continue distally in four distal tendons that insert into the middle phalanx of the... 

At the volar aspect of the wrist, nine flexor tendons enter the carpal tunnel to reach the fingers. There are four tendons from the flexor digitorum superficialis for the second through fifth fingers, four from the flexor digitorum profundus for the same fingers and the flexor pollicis longus tendon. 

Fig. 10.33 a,b. Schematic drawings illustrate typical sites of overuse tendinopathies in the a dorsal and b ventral wrist, including Ay de Quervain tenosynovitis B, intersection syndrome C,extensor pollicis longus tenosynovitis, ),extensor carpi ulnaris tenosynovitis E, flexor carpi radialis tenosynovitis F, flexor digitorum superficialis and flexor digitorum profundus tenosynovitis Gy flexor carpi ulnaris tendinopathy... 

After exiting the carpal tunnel, the tendons of the flexor digitorum superficialis and profundus pass deep to the palmar aponeurosis and enter the osteo-fibrous digital tunnels. In each finger, the two ten-... 

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