- See:
Forearm Extensors :
- Anatomy:
- origin: lateral condyle of humerus;
- insertion:
- 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;
- action:
- 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);
- Discussion:
- 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. Greenbaum B, Itmura J, Vangsness CT, et al: J Bone Joint Surg Br 81:926-929, 1999
Anatomic Factors Related to the Cause of Tennis Elbow
