I started out using SPD when i bought my trike, but I never liked them. Walking with shoes with SPD cleats is not easy if they are racing shoes, there are shoes with a recessed mounting position for the cleats but it is still awkward. Checked out on the internet, it turns out that there are basically three positions for mounting the cleats Ball of the toe, mid toe and midfoot. The problem is that most shoes only have mounts for mounting the cleats in the first two positions, most midfooters have to modify their shoes. Which position fits who is up to their cycling style and to a lesser extent preference. I was in the process of modifying my shoes for midfoot position when I ran across the Terra Trike Strapped Heel Support Pedals. The good things with them is that you can use any shoe you like, and the spindle are in the midfoot position, I absolutely love them. If you prefer another position there are heel sling which you can adjust to any position but then you can't pedal all way around which some persons prefer, they imagine it gives them more power but research has proven that they gain very little if any power at all