- See: Forearm Extensors :
- origin: lateral condyle of humerus;
- this tendon inserts into the base of 3rd metacarpal and is in direct relationship with the ECRL, which inserts into the base of the 3rd metacarpal;
- extension and abduction of the hand at the wrist;
- ECRB is prime dorsiflexor of the hand;
- synergists: ECRL, ECU;
- nerve supply:
- PIN (C6 > C7, C8) supplies ECRB & supinator muscles before entering arcade of Froshe;
- PIN may be compressed by the tendinous origin of the ECRB;
- w/ humerus frx need to r/o radial nerve palsy (1st nerve branches distal to frx site will be ECRB & supinator);
- pathology of origin of ECRB may cause tennis elbow syndrome, however, PIN syndrome may also cause "lateral epicondylitis;
- osteophyte from 2nd & 3rd carpal metacarpal joint (capal boss) is just beneath ECRB & ECRL, and may cause a tendonitis;
- Rupture of ECRB:
- important consideration for wrist prosthesis in R.A.;
- balance of extensor tendons is of primary importance, esp ECRB;
- w/o this tendon (due to rupture), there is no effective wrist extension;
- do not confuse w/ rupture of ECRL or EDC;
- if active wrist extension does not go beyond neutral, or if there is significant palmar carpal subluxation, integrity of ECRB should be questioned;
- tendon transfers have been successful, and therefore, when ECRB tendon is not intact, arthrodesis is indicated
Tennis elbow. The surgical treatment of lateral epicondylitis.
Lateral extensor release for tennis elbow. A prospective long-term follow-up study.
Microscopic histopathology of chronic refractory lateral epicondylitis.
Extensor carpi radialis brevis, an anatomical analysis of its origin.