When I was ready to return to hunting, I realized the use of my hands had been so impacted from my injury they would not allow me to squeeze a trigger. A fellow that I met, Marshall Thayer, offered to work with me to create an adaptive trigger device. Ones were available commercially but they were extremely expensive. If you look at the picture below you can see the very clever piece of adaptive equipment Marshal devised. Number 2 in the picture shows a channel that goes all the way around the trigger adapter. The trigger of the shotgun is fitted into the channel and then is held in place by two small allen screws which are labeled number 3. The area marked number 1 sticks out beyond the trigger guard and serves as my trigger. I place my index finger on that part and am able to pull the adapter back which in turn fires the gun. It is so simple and yet so efficient. About 4 years after this was made, it fell off my gun while hunting and I didn't discover it was gone until I got home.
Unfortunately, Marshall had passed away several years earlier. We have tried to reproduce this trigger adapter using 3D printing but have met with only limited success. Handihelp has come to realize trigger sizes differ and the space behind the trigger varies so there is no guarantee one will work on all guns.
There are now five other alternative trigger adapters shown on this website.