SUPERFICIAL EXTENSORS OF FOREARM-EXTENSOR DIGITORUM

SUMMARY

1. O: lateral epicondyle of humerus (common extensor origin).2. Tendons pass under the extensor retinaculum to pass to the fingers where they form the dorsal expansions/extensor hoods. 
3. I: extensor expansion of medial 4 digits. 

4. NS: posterior interosseous branch of radial n. 
5. A: extends medial 4 digits & wrist. 

Reference(s)

R.M.H McMinn (1998). Last’s anatomy: regional and applied. Edinburgh: Churchill Livingstone.
Gray, H., Carter, H.V. and Davidson, G. (2017). Gray’s anatomy. London: Arcturus.