People with mobility problems should look into treating their body to a low impact cardio routine. It's always essential that you consult your doctor before under-taking a new exercise program, particularly if you have health issues. Provided your doctor or health care professional gives you the OK, start off slow with the exercises recommended below.
Alternating squat with front kick
This is a simple exercise that's great for getting your heart pumping. 1. Stand with feet shoulder width apart and hold your hands out parallel with the floor (or arms crossed on your chest). 2. Start by squatting down and kicking one foot out in front to hip level. 3. Bring foot in and squat again, then kick with the opposite foot on the way up. This kind of low impact cardio movement can be done for a full 20 minutes, or mixed in with other movements.
Alternating Side Lunges
With your hands on your hips, or out in front of you parallel to the floor: 1. slowly lift one leg to the side while bending the knee of the leg planted on the ground. 2. Once you've bent the knee of the planted leg your going to lightly lunge the leg which is in the air to the side and plant it on the ground, while lifting the opposite leg. Continue alternating back and forth.
Use Your Imagination
Anything that doesn't require bone-crunching impact to your feet and joints can be considered a low impact cardio exercise. Marching in place while lifting your knees as high as you can comfortably is a great low impact exercise. You can also consider controlled front lunges; either standing in place or lunging across your lawn (grass is great for absorbing impact). Power walking with impact-absorbing shoes on is a great thing to do with friends or while walking your dog for exercise also.