What is your opinion on arm bikes for pitchers? I recently had surgery on my hip (pitched with a torn labrum in my lead hip all last season) and am limited as to what workouts I can do. I did an interval program on our arm bike machine and thought it might be something worth implementing in my regular weekly schedule. I couldn't find any solid evidence or even discussion about this anywhere else and just wanted to know what your thoughts were.
Honestly, I don't have any experience using arm bikes. They might provide some benefit but my initial reaction to reading your post was "eh." I think you could spend your time doing other things that would benefit you more such as core stability work and upper body strength/maintenance.
This all depends on how many weeks post op you are and how you are feeling but your first priority should be to get your hip and lower body back to 100%. In the meantime there is still work you could be doing to develop core strength and really target areas of your upper body that need work. A few examples could be mobility, cuff work, soft tissue work, and overall strength.