Exercises like step-ups can improve stability, strengthen muscles, and fix imbalances to help relieve knee pain.yacobchuk/Getty ImagesIf you get knee pain or injuries in the gym, that could be from sitting all day.Exercises that strengthen and stretch the leg muscles effectively will help protect knees.For healthier joints, aim to move regularly and work on your balance and stability.Simple exercises can help prevent knee pain from derailing your routine, according to a physical therapist.Andrey Simeonovski, a physical therapy doctor, recently spent a week in Kathmandu as part of Operation Walk, helping rehabilitate patients who'd had knee replacement surgeries.He said a major takeaway from the experience is that consistently putting your body through the same motions can cause problems, whether you're sitting all day or doing repetitive physical tasks."It's a variety of movements that are important for your health in your body," Simeonovski said.Here are some exercises that offer your joints a range of motion to strengthen the surrounding muscles.