It is fairly convenient to exercise from a bed, especially if your legs no longer function correctly. And if your legs no longer function properly it is very important for the rest of your body to get a lot of exercise. Here are a few simple exercises that can be done from your bed using dumbbells. There are, of course, many more exercises you can do with and without dumbbells.
Starting with your hands fairly close to your armpits just raise the dumbbells straight toward the ceiling. I usually do sets of 50 varying the weight depending on who I'm trying to impress.
Many people tend to forget to exercise their triceps muscles. Some overdevelop their biceps and get a muscle-bound look. The body is made up of sets of opposing muscles. Some of them extend and some contract. Biceps pull your hands toward your shoulders while triceps push them away. You need to exercise both sets of muscles in order for your body to work correctly. With my elbows always pointed toward the ceiling I lift and lower the dumbbells toward the ceiling and then back to the top of my head.
Extend your arms out to the side with your elbows slightly bent (don't lock your elbows) and then raise your arms toward the ceiling. This will exercise your chest muscles.
If you have trouble controlling the dumbbells in the over-the-head position you might just use one dumbbell and hold it with both hands. It's a much more stable position and is easier to control.
I do some of my exercises sort of hanging over the corner of the bed. I can put one hand on the floor for support and raise the other hand up to my armpits. As always, I use whatever weight is comfortable yet still provides good exercise.
A variation is to hold my upper arm parallel to the floor and raise the dumbbell from the floor to a fully extended (backward) position.
One form of pushup uses a bent body; that is, knees are bent and my hips are bent and I just do pushups. I look sort of off-balance here because I'm almost at the bottom of the pushup. This exercise is good for maintaining balance.
I have just barely enough back and stomach muscles so that I can also do a straight body pushup. But, since I have no movement or feeling in my legs, I cannot keep my knees straight. If I could lift my knees off the bed so that I was balanced on hands and toes, I would get more out of this exercise. Since I cant, I make up for it by doing more repetitions.
Slowly raising and lowering your arms straight out to the side with your elbows slightly bent is an exercise for fairly light weights. Sloooow is the keyword here.
Drop one leg over the edge of the bed and reach for your toes with both hands. This will stretch your ham string muscles. I have to be careful because I have no feeling in my legs. If I overstretch the muscle I won't be able to feel it.
Sitting with your feet pulled in toward your stomach and your knees very gently pressed down toward the mattress stretches all sorts of muscles in your back and legs.
I'm using a special belt to stretch my calf muscles here. Before I got the special belt, I just used a regular belt for my waist. I just wrap the belt buckle around my foot and gently pull my foot toward my waist.
I don't have to caution you to be careful with this stretch. Your shoulder muscles will definitely let you know when you stretch them. You can use a piece of rope or a belt. It has to be long enough for you to comfortably stretch your arms. If it is too uncomfortable, use a longer rope.
There are probably thousands of exercises that you can try from your bed. The ones shown here may or may not be suitable for your condition. A physical therapist can give you all sorts of exercises that target your particular needs. Any physical exercise program should first be okayed by your doctor. Good luck.