The Frog Arm is an experimental device for people who have some degree of paralysis distal to the elbow. Extending the elbow opens the fingers. This device does nothing to close the fingers, but many hands in paralysis are closed at rest, so they should close again on their own when the user bends the elbow.
The Frog Arm is an experimental device. It may not be effective for your circumstance. If you have any doubts about safety, please do not use the device without the guidance of a medical professional. And please provide lots of feedback to me. If you can share your successes and failures with the device, or think of ways to improve the device, I would be very grateful.
Here is the instructions document as it stands. I will work to improve instructions in the coming months, so check back from time to time.