I have to agree that with a broken elbow, the use of a trike might be best. There would be no balance issues when first staring out, they are easy to steer one handed and as previously mentioned, one could be set up with a single lever operating both brakes. I personally ride a TerraTrike Path tadpole trike and love it. May I suggest having your brother contact TerraTrike directly and inquire whether one of their California dealers offers rentals. That by itself could be a cost savings for him, why buy if he can rent. Have him try this link: http://www.terratrike.com/index.php The people at TT are very helpful.