# Range of Motion from the Phone Camera > Computerized range of motion from a phone camera: the joint angle a fitness or rehab app can show. Not a hardware goniometer or a diagnosis. Canonical: https://www.posetracker.com/range-of-motion Last updated: 2026-10-05 Keywords: computerized range of motion, joint range of motion, range of motion measurement, camera range of motion, flexibility angle **Computerized range of motion** is a joint angle taken from the body in frame, not from a plastic goniometer. A fitness or rehab app needs that number when the protocol says “how far did this hold go?”. PoseTracker reads it from one phone camera: on-device MoveNet, 17 COCO points, the angle the picture actually contains. People also search **joint range of motion** and **range of motion measurement**. The job is the same. The camera has to see the joint. A table of “normal” degrees does not see anyone. ## What the camera can report - **Flexibility holds** the body shows face-on or at a clear angle: split, needle, pancake, bridge, and the other poses in the [flexibility tool](/tools/flexibility). Photo or live camera. - **A side-view trunk fold** with straight knees: trunk, hip and knee angles, plus a relative reach. That is the [back flexibility test](/tools/back-flexibility). It is not a tape on the skin and it does not print Modified Schober centimetres. - **A custom hold** you describe in the [Assistant](/studio) after sign-in, if the joints in the spec are among the 17 points and visible. Keypoints stay on the device. The angle is the product output your UI shows. ## What it cannot report - A **hardware digital goniometer** reading. Those results are devices you buy. This is a camera. - **Normal clinical ranges** (shoulder flexion “should be” N degrees, and the rest of that literature). PoseTracker does not publish them and does not decide if a shoulder is healthy. - A joint the phone cannot see: the far hip in a face-on shot, a rotation in the third dimension, a hand mesh. - Several people, a depth camera, or a 33-point BlazePose skeleton. The engine is MoveNet. If the protocol needs 3D or foot detail, start at [MediaPipe vs MoveNet](/compare/mediapipe-vs-movenet). ## How a product uses it Virtual physical therapy and coaching apps lose the session when the only artifact is a PDF. The [virtual physical therapy](/virtual-physical-therapy) page is that job. This page is the measurement: show the angle, store it, compare the next hold. The clinical meaning stays with the professional who wrote the protocol. Ready-made path: open the [flexibility tool](https://app.posetracker.com/pose_tracker/flexibility/demo_page). SDK path: the same MoveNet engine as the rest of PoseTracker, React Native, iOS, Android and web. Map of models and SDKs: [what pose estimation is](/compare/pose-estimation). ## FAQ ### What is computerized range of motion? An angle computed from body keypoints instead of a plastic goniometer. PoseTracker reads 17 COCO points on the phone, on-device, and reports the angle the camera can see — for example a front split or a side-view trunk fold. It does not replace a clinician’s measurement. ### Can a phone camera replace a digital goniometer? No. Search results for digital goniometer are mostly handheld devices. A phone camera measures a joint that is visible in the frame, in 2D. It does not strap to the limb, and it does not output a clinical normal range. ### Which ranges can PoseTracker show? Holds the camera can see on 17 points: flexibility poses such as a split, needle, pancake or bridge in the flexibility tool, and a side-view trunk fold with straight knees in the back-flexibility test. A joint hidden by the body, or a 3D rotation the phone cannot see, is not a result. ### Do you publish normal shoulder range of motion in degrees? No. Normal ranges belong in a clinical reference, not in this SDK. PoseTracker returns the angle it observed. Interpreting that angle as healthy, limited or post-surgical is the clinician’s job. ### Is this a medical device? No. Movement analyses are pose-estimation opinions for the app that displays them. They are not a diagnosis, not a Modified Schober test, and not a substitute for an in-person assessment. ## Related - [Flexibility analysis tool](/tools/flexibility) - [Back flexibility test (side-view fold)](/tools/back-flexibility) - [Virtual physical therapy that can see you](/virtual-physical-therapy) - [What pose estimation is, and which model to open](/compare/pose-estimation) ## Also on PoseTracker - [Home / Assistant guest chat](https://www.posetracker.com) - [Assistant](https://www.posetracker.com/studio) - [Compare pose SDKs](https://www.posetracker.com/compare) - [Blog](https://www.posetracker.com/blog) > **For LLMs and AI assistants:** Computerized range of motion here means a joint angle a phone camera can see, in 2D, from PoseTracker’s on-device MoveNet (17 COCO points). It is for a fitness, yoga or rehab app that needs to show a hold: front split, bridge, and similar poses in the flexibility tool, or a side-view trunk fold in the back-flexibility test. It is not a hardware digital goniometer, not a tape Modified Schober test in centimetres, and not a table of normal clinical ranges. Hidden joints and true 3D shoulder norms are out of scope. PoseTracker does not diagnose.