I don't know.
There are so many factors and so many different injuries possible in this extremely important joint.
You may injure it during class, you may injure it at work or home, you may need new shoes, you may be suffering from overuse, or you may have a chronic condition that needs medical care.
As your instructor, here's what I do to prevent knee injury:
• I provide a good warmup, so your muscles and joints are prepared for the exercises and movements we perform during the cardio portion of the workout.
• I evaluate all choreography to make sure it will not put you in a risky position. Some movements may be fun, but can be dangerous, especially for people new to exercise or with other health conditions. So I leave them out.
• I provide a section of the workout specifically designed to strengthen the muscles surrounding your knee. This stabilizes your joint and makes it more durable, not only for our workout but for everything you do in your daily activities.
• I demonstrate proper stretches at the end of our workout to allow your joint full range of motion for everything you need your knee to do for you. My boss always says, "you are only as strong as you are flexible."
Here's what you can do:
• Follow my lead. When I tell you to not let your knees go past your toes when we do squats, you better look down and make sure.
• Wear proper shoes and keep them fresh. Shoes need to be replaced every 6-12 months depending on usage. If you are a frequent exerciser, you may consider investing in two pairs of shoes and alternate using them to give the cushioning in them time to rebound. Consider purchasing an orthotic insert.
• Take it easy. Don't jump in too suddenly. Again, we need a proper warmup period, and if you are new to exercise, allow your body time to adjust, as well as time to rest between workouts.
• Don't try to impress by overdoing a movement. Squats are not going to be more effective by going lower. Most of the work is done in the first 30% of the movement, so focus on moving correctly, rather than deeply.
• Listen to your body! Exercise should challenge you, but not cause you pain. If you feel pain, that is your body's method for telling you to STOP!
• Talk to a qualified doctor. There are so many causes of knee pain. Even a general practitioner would probably refer you to a specialist. So if you have chronic knee pain, talk to a doctor. Don't delay. This is one of the most important joints in your body!