Extensor Carpi Radialis Brevis

Lateral (wrist extensor) and supinator Supplied by the radial and the posterior interosseous nerve, this group consists of the supinator, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum communis, and the extensor carpi ulnaris. 

Owing to a differential diagnosis list which mainly includes wrist problems (i.e., de Quervain disease and Wartenberg neuropathy), the most important tendinopathy of the mobile wad compartment affecting the tendons of the extensor carpi radialis brevis and longus as they traverse the components of the first dorsal extensor tendon compartment, so-called intersection syndrome, will be discussed in Chapter 10. 

Fig.l0.17a-f. Extensor tendons second and third compartments, a-c Transverse 15-7 MHz US images obtained distal to the Lister tubercle with d-f diagram correlation. From cranial (a) to caudal (c), US shows the extensor pollicis longus tendon as a thin fibrillar band (arrowheads) crossing the extensor carpi radialis brevis (ECRB) and longus (ECRL)... 

If the electrode is inserted too proximally it will be in the extensor carpi radialis brevis if inserted too distally it will be in the extensor pollicis brevis if it is inserted too ulnarly or too superficial, it will be in the extensor digitorum communis. 

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