My father, 98yo, bought a tadpole style recumbent 4 years ago. He loves to ride it, and this is one of his major exercises. He is getting a little weaker and less surefooted and we are getting concerned about a possible fall when he is getting on the bike. We got the set of upright handle things that are to help him lower himself down but I think he needs some balance help as he backs up onto the bike. I was either visualizing some sort of rails that he could park the bike between bolted to the garage floor, or some of those hand hold triangle shaped handles like you see in hospital beds, hanging 2 of these from the ceiling of the garage. Has anyone done anything like this and have pictures to share?

At least with a trike, balance is not an issue once seated.

Any balance aid would best be mobile with the trike, in case he needs to get up to use the restroom in a park, etc. I would try finding some walking canes, I like with a T-top handle, and adjust to the shortest position, two of them, for lowering down and boosting himself up out of the seat. Key here is easy stashing of said canes, you might be able to rig a tall slender can attached to one side of the seatback to drop the canes into, or somehow stash under the seat cross-wise, provided the cane length is well shorter than the front wheel track width (wheel center to wheel center) so doesn't get snagged in a tight turn. You could also try adjustable height hiking poles, those are now cheap in pairs at places like walmart or on amazon, with those, you would not be "pushing" down on the T-cane, but instead "pulling" on the vertical grip with strap, that might be easier when fully seated and knees bent, when assist from the arms is most important to be easy on the knees. Hiking poles come in 2-piece and 3-piece, both adjust short but the 3-piece adjust shorter and are more compact when collapsed. Cheaper aluminum poles are fine, weight is not critical in this application, but stiffness and stability are, as well as ease and speed of collapsing and extending, there are different ways they lock there.

Been riding recumbent trikes since 2003 and as I get older it gets harder to get out of my Catrike 700, one of the lowest, most reclined tadpole trikes. There are aids offered by some of the manufacturers and from an outfit called Terracycle that can help getting up once seated. There are also models that are higher seating like the Catrike Villager but that is an expensive option. Check out the Bentrideronline website for lots of good information. https://www.bentrideronline.com Here's the assist bars offered by Catrike for their trikes https://www.catrikestore.com/Catrike-Assist-Bar-Pair

Thanks for the prompt response! We do have some of the 3 part hiking sticks and will try this. The reason I was focusing on something semi-permanent in the garage is that he never rides anywhere that it would be necessary for him to dismount. He literally gets in the bike and rides up and down the cul-de-sac a number (usually 10) of times. What I am concerned about is the very small time he is "shuffling backwards" around the pedals. Once he gets past this point, he is able to use those arms that I mounted on the bike (the name escapes me) to lower himself down. He just recently gave up driving his car and I really want him to have the ability to do the bike if he can do it safely.

Got it. Triangular hospital pullup bar with chain or rope should do it, provided that where you anchor it to the garage ceiling clears the garage door when open, and is anchored sufficiently to support his full weight X2 as a safety margin, as he may yank on it dynamically. So ideally, not just into a 2x4 stud that supports the ceiling drywall, but preferably a floor joist for above, with the load spread over several lag screws. Bikes are hung from garage ceilings all the time, but he's heavier than a bike. By the way, those double hook bike/kayak/canoe lifts that used to cost $50+, a good number of years ago they were available at harbor freight for like $8 on sale.

The ceiling-mounted trapeze handles are a good idea, but make sure they’re anchored into the joists properly. You could also look into "stand-assist" bars that are designed for couches; they might provide a more stable grip than something hanging

Also take into account, that above a certain height, people can't push down on a horizontal bar, they need to pull up. The range of use, standing to low recumbent seating, means one height horizontal bar may not be enough; You might need lower bar for when near seated, and higher bar for when near standing. My knees are weaker than they used to be, I need to use a cane and such for stairs and lowering and raising myself from the ground, it makes a big difference in babying my knees, one of which has a cartilage tear.