Abstract: A device for strengthening extensor muscle groups of the forearms and hand consisting of a leaf spring with a generally planar portion and an integrally formed arcuate portion containing a plurality of tines. The user straps the device onto the posterior surface of the forearm and inserts his/her fingers into the finger sleeves resulting in a closed fist position of the hand. The user uses the exterior muscle group to straighten his/her hand against the spring force of the device. The device is intended as a therapeutic implement for individuals with carpal tunnel syndrome, elbow and wrist tendinitis and similar injuries or for general muscle strengthening.