From the case:
Anterior forearm muscles (Gray's illustrations)

Superficial and deep muscles of the anterior forearm compartment.
Case Discussion
Original diagrams from Gray's anatomy, now out of copyright. These diagrams have been reproduced from Gray's Anatomy 20th US edition which has now lapsed into the public domain
- https://commons.wikimedia.org/wiki/File:Gray414.png
- https://commons.wikimedia.org/wiki/File:Gray415.png