My 86-year-old grandfather had his knee replaced with a new joint last month. When I take him in to see the physical therapist, she puts electrical stimulation on his thigh muscle. What does this do?

There are several different uses for electrical stimulation. In your grandfather’s case, an electric current is used to make the thigh muscles contract. By using this kind of stimulation, more muscle fibers are called into action and with more force. Repeating this type of treatment without completely tiring the muscle can help build your grandfather’s muscle strength.