Answer
I understand your concern, I've heard of children getting their fingers caught in treadmills etc. I don't know what your child's schedule is like, but if it's possible to do your routine while he is taking a nap that's a thought. Another possibility is to exercise with your child with no equipment involved, such as going for a walk, throw on some music and dance around the living room with him. As far as another piece of equipment the elliptical machine is very good. Hope I helped with ideas.