This anomalous hand muscle presents as a a “fusiform, soft prominence” between the 2nd and 3rd extensor tendons near the wrist to hand. It can become sore as it is compressed against the extensor retinaculum and possibly irritates the posterior interosseous nerve. Botox injections helped one case.
PM R. 2013 Dec 21. pii: S1934-1482(13)01085-X. doi: 10.1016/j.pmrj.2013.09.010.[Epub ahead of print]
Treatment of Extensor Digitorum Brevis Manus Myalgia With Botulinum Toxin.
Wendel I, Cole J.
- Must be considered in Differential diagnosis of dorsal hand/wrist pain and can be confused with ganglion cyst
- “Digital extension and abduction, along with wrist flexion, promotes detection”
- Case not helped by neutral wrist splinting and ergometric workstation changes
- Botox 35 units into area gave relief for 1.5 years
Comment – Another item to look for in our computer age… I have found tender nerve desensitization with dilute sugar injections (“neuroprolotherapy”) helpful using 3% glycerin (by volume) in D5W very helpful and wonder if repeated superficial injections of that might have done the trick. With practice, you can actually feel nerves like threads (it helps that they are tender) and injecting overtop them(not in them) desensitizes them – first time for 4 days – then longer with average of maybe 6 weekly sessions needed.