Practical Guide to Home Self-Checks for Knee Health Using MAI Motion on Your Phone Camera

Knee discomfort is a common issue for people of all ages, often resulting from daily activity, injury, or aging. Fortunately, digital health technology now makes it easier than ever to keep an eye on your knee health from the comfort of home. One handy tool is MAI Motion , a smartphone app that uses your camera to track knee movement with impressive accuracy. In this article, we'll guide you through easy home self-checks using MAI Motion . You'll learn how to set up your checks, understand your results, and integrate these insights into your knee care routine. With just a few simple steps, you can take charge of your joint health and catch potential concerns early.

Understanding MAI Motion Technology

MAI Motion uses your smartphone camera and advanced computer vision to record and analyze how your knee moves. When you film yourself, the app measures important details like the angles during movement and the speed of your joint action—think of it as having a digital physiotherapist right in your pocket.

Studies show that mobile motion tracking apps like MAI Motion are surprisingly accurate, delivering results nearly on par with the specialized—and often expensive—equipment used in clinics. For example, research found that MAI Motion can capture reliable biomechanical data using a streamlined three-repetition test, making the process both efficient and effective (Wen et al., 2025). Marker-less motion tracking also offers a natural, unobstructed way to measure movement, as you won’t need to attach physical markers to your body (Armstrong et al., 2022). And standard smartphone cameras have now been shown to collect clinically useful motion data, putting accessible knee assessments within reach for almost everyone (Armstrong et al., 2024).

To make things simple: “Motion tracking” means digitally measuring how your body moves, and “range of motion” is how far your knee can bend or straighten. All you need is a smartphone—no special gadgets required—which makes MAI Motion a convenient and approachable tool for almost anyone.

Step-by-Step Guide to Your Home Knee Self-Check

To get the best results, start by setting up your space. Place your phone on a stable surface—a tripod is ideal, but a steady stack of books works nicely too. Make sure the area is well-lit and the background is clear, so your movements are easy for the app to capture. Position your phone about one meter away from your side, with the camera aimed at your knee to catch your full range of movement as you bend and straighten.

Open the MAI Motion app and begin by calibrating: you’ll tap three key points on your body—your hip, knee, and ankle—to help the app recognize your specific positions. Next, slowly bend and straighten your knee three times, following the app's guidance as it records each repetition. Current research suggests that three repetitions are enough to produce accurate data, and it’s less tiring than longer tests (Wen et al., 2025). For best results, wear fitted clothing rather than loose outfits—this makes it easier for the app to track your joints precisely.

Careful setup and following these steps will help you collect the most accurate data about your knee movement.

Interpreting Your Results for Effective Knee Care

After your self-check, MAI Motion provides a report highlighting your knee’s range of motion and comparing both sides. A healthy knee typically bends past 120°, and the movement of both knees should be symmetrical. If you see a difference greater than 10° between knees, or if one knee can't bend beyond 120°, these could be early signs worth discussing with a professional.

Spotting these changes early can help you prevent more serious issues. Your recorded data can also be valuable for tracking progress if you're rehabbing after an injury or monitoring a chronic condition. Think about logging your results in a simple spreadsheet or dedicated health app, so you can see trends over time and notice any changes as they happen.

Integrating Self-Checks into Your Daily Routine

For ongoing benefits, try to repeat these self-checks once a week, ideally after a gentle warm-up or physical therapy session when your muscles are ready for movement. Pairing your checks with regular strengthening and stretching exercises can go a long way in maintaining knee health.

MAI Motion ’s visual charts make it easy to see your progress—which can be a real motivator to keep up your routine. If you ever have trouble with tracking—like poor motion capture or blurry feedback—try improving the lighting, adjusting your phone’s angle, or restarting the app. Making these self-checks part of your regular routine can help you stay tuned in to your knee health and support your overall wellbeing.

Limitations and Best Practices

While MAI Motion offers a user-friendly way to monitor your knees, it does have limitations. User errors, camera quality, and software interpretation can affect the data’s accuracy. Research suggests that the three-repetition protocol offers a good balance between precision and effort, but remember that MAI Motion is designed for screening and self-monitoring—not as a replacement for professional medical evaluation (Wen et al., 2025). Marker-less systems are well-suited for small-scale monitoring but shouldn’t be the only tool you rely on for diagnosis (Armstrong et al., 2022; Armstrong et al., 2024).

Always follow the app’s instructions carefully. Avoid moving in ways that cause pain, and ensure your phone is placed securely to prevent accidents. Your privacy is protected—your videos stay on your phone unless you choose to share them. By sticking to these common-sense guidelines, you’ll get the most benefit from your at- home knee checks while staying safe and confident.

With MAI Motion , taking care of your knees can be simple, accessible, and empowering. Its easy setup, reliable tracking, and visual feedback make regular self-checks a practical way to stay proactive about your joint health. Give it a try, and start taking confident steps toward stronger, healthier knees!