A digital goniometer and biomechanics lab in your iPhone
Anglaxis measures joint angles, range of motion (ROM) and movement mechanics from video — frame by frame, on your device. Built for physical therapists, coaches, athletes and researchers.
Requires iPhone with iOS 18 or later.
Goniometry, powered by your phone's camera
Anglaxis is a frame-by-frame video analysis app that works like a digital goniometer for the whole body. A traditional goniometer is a protractor-style tool for measuring a single joint angle by hand; Anglaxis measures those same joint angles and range of motion from a video clip — and adds biomechanics metrics that a handheld tool can't, like how an angle changes across a running stride or a squat. On-device AI pose detection (Apple Vision) does the first pass, and every measurement stays editable so your numbers are trustworthy. It's a modern alternative to clinic goniometry and lab kinematics for sports and movement screening.
Measurement you can trust
Precise digitizing tools plus AI that does the first pass — so you verify, not start from scratch.
Angle & distance tools
Freeze any frame and place 3-point joint angles, distances and paths — a precise on-screen goniometer with zoom-to-digitize accuracy and fine handle adjustment.
AI auto-angle
Tap a joint and on-device Apple Vision pose detection places the angle for you, with a confidence score. Every AI estimate stays fully editable.
Range of motion over time
Track a joint across a whole clip to chart its angle over time and compute range of motion, peak flexion and peak extension — then jump straight to those frames.
High-frame-rate capture
Record at up to 120/240 fps and review in true slow motion with frame-accurate stepping and a graduated scrubber.
Annotate & compare
Draw, label and attach voice notes to specific frames. Compare two frames side-by-side to see change across a movement.
Private & on-device
Pose detection and measurement run on-device. Clips are never uploaded to Anglaxis; projects sync through your own private iCloud.
From handheld goniometer to video goniometry
With a physical goniometer you align two arms to a joint and read one angle at one instant. With Anglaxis you capture the movement once and measure joint angles on any frame — knee, hip, elbow, shoulder — then quantify the full range of motion across the motion. Because it's video, you also get time-based kinematics: peak flexion in swing, knee angle at the bottom of a squat, hip extension at toe-off. It's goniometry plus motion analysis, in one app, with no markers or external hardware.
Sport & movement analysis
Record or add a clip and Anglaxis auto-detects the filming plane — side-on or front-on — and applies the matching analysis.
Metrics include hip & knee range of motion, pelvic drop, dynamic knee valgus, elbow and shoulder motion, trunk lean, and hip–shoulder separation — each shown with reference guidance you can benchmark against your own norms.
Who uses Anglaxis
Physical therapists & clinicians
Measure ROM and screen movement — ACL return-to-sport, patellofemoral pain, ankle dorsiflexion, hip-abductor control — with the plane and camera setup for each protocol.
Coaches & athletes
Analyze running, cycling, golf and lifting technique frame by frame, and track changes across sessions.
Strength & conditioning
Screen squat depth, landing knee valgus, pelvic drop and trunk control for performance and injury-risk coaching.
Researchers & educators
Fast, repeatable 2D kinematics in the field or lab — apply your own validated thresholds and reliability.
Frequently asked questions
Is Anglaxis a goniometer app?
Yes. Anglaxis is a digital goniometer app for iPhone. Instead of a physical protractor-style goniometer, it measures joint angles from video: freeze any frame and place a 3-point angle, or let on-device AI place it for you. Every measurement stays editable for research-grade accuracy.
Can Anglaxis measure range of motion (ROM) from a video?
Yes. Record or import a clip, then track a joint across the whole clip. Anglaxis charts the joint angle over time and computes range of motion, peak flexion and peak extension, and lets you jump straight to those frames.
What movements and sports can it analyze?
Running, cycling, walking gait, baseball pitching and hitting, golf, squat, jump squat, overhead press, lateral step-down and reciprocal hip extension — measuring hip and knee range of motion, pelvic drop, knee valgus, trunk lean, elbow and shoulder motion, and hip–shoulder separation.
Does it work offline and keep my videos private?
Yes. Capture and pose detection run entirely on your device with Apple's Vision framework. Clips are never uploaded to Anglaxis; projects can sync through your own private iCloud account.
Is Anglaxis a medical device?
No. Anglaxis is a measurement and decision-support tool for coaches, clinicians and researchers. It does not diagnose, treat or prevent any condition, and AI estimates from 2D video are a screening aid, not a lab-grade clinical measurement.
How much does it cost?
Anglaxis Pro is $24.99/year for 1 device or $49.99/year for 3 devices, each with a 3-day free trial. Recorded videos stay viewable even if the subscription ends. Universities and clinics can request bulk licensing.
Simple, subscription pricing
Start with a 3-day free trial. Your recorded videos stay viewable even if your subscription ends.
Pro · 1 Device
- All measurement & annotation tools
- AI auto-angle & sport analysis
- High-frame-rate capture
- Private iCloud sync
- 3-day free trial
Pro · 3 Devices
- Everything in Pro · 1 Device
- Use on up to 3 devices
- Ideal for small teams & clinics
- Manage seats in-app
- 3-day free trial
Universities and organizations needing bulk seats: [email protected]