One of the first questions people ask about KineTrue is some version of: "How does it know whether I'm doing the exercise right without sensors strapped to me?" The answer is a computer-vision technique called pose estimation, and it runs on the same camera you use for video calls.
From video frames to body landmarks
As you exercise, the software analyses the camera feed and identifies key points on your body: shoulders, elbows, wrists, hips, knees, ankles. These points are called landmarks, and together they form a simplified skeleton of your pose in each frame. KineTrue builds on the BlazePose model family from Google's open-source MediaPipe project, which tracks 33 body landmarks and was designed to run in real time on ordinary phones and laptops, directly on the device. The glowing dots and lines you see on the session screen are those landmarks, drawn live.
How accurate is a webcam, really?
Reasonably accurate, and researchers have measured it. A 2023 study in PLOS ONE compared webcam-based pose estimation against a marker-based optical motion-capture system (the laboratory gold standard) for measuring joint range of motion in 25 adults, and found substantial to almost-perfect agreement for most joints, with high test-retest reliability. That said, a webcam is not a motion-capture lab. KineTrue treats what the camera sees as guidance during your session and as context for your therapist to review, not as a diagnostic measurement.
From landmarks to feedback
Landmarks on their own are just coordinates. The useful part is what gets computed from them: joint angles, how far you've travelled through a movement, whether your knee stays aligned during a squat, whether you're rushing the return phase. Each exercise has its own expectations, so the feedback you see, like "keep your knee aligned" or "move slowly as you return," comes from comparing your live movement against how that particular exercise should look.
The same analysis counts your repetitions and tracks movement quality across the session, which is what your therapist later reviews.
Why no wearables is a feature
- Nothing to charge, calibrate, lose, or strap on before a session.
- It works with equipment you already own: a phone, tablet, or laptop.
- There's no extra hardware cost standing between you and your program.
Camera access is always in your control: your browser asks for permission before a guided session, and the public KineTrue website never requests it.