biomex.studio — Motion Analysis

Load a video to begin analysis

MP4, MOV, AVI, WebM · All analysis runs locally

Space=play · ←→=step · Shift+←→=±10 · V/M/L/A/C/R/D/P/O=tools · F=copy fwd · Right-click=track · Esc=cancel

Tutorials Step-by-step

Step-by-step guides for common motion analysis tasks. Each workflow is self-contained — follow it once, use it forever.

Fundamentals Start here

Measuring Joint Angles

Track knee flexion (or any joint angle) across a movement sequence and export the angle-time curve.

Load your video
Open biomex.studio and click Choose Video File or Load from URL.
Set the framerate
In the Calibration tab, set the Capture FPS to match your camera (30, 60, 120, 240 fps etc). This is critical for velocity and acceleration accuracy.
Navigate to the start
Use the scrubber or arrow keys (← →) to find the frame where the movement begins.
Place the angle
Select the Angle tool (A) and click three points: proximal joint → vertex joint → distal joint. For knee flexion: hip → knee → ankle.
Track across frames
Use Copy → Next (F) to duplicate points to the next frame, then drag each to its new position. Or place individual Markers (M) on each joint and use auto-tracking (right-click → Start Tracking) for faster digitisation.
View kinematics
Click 📈 on the angle annotation card. Switch between Position (angle°), Velocity (°/s), and Acceleration (°/s²).
Export
Click Export CSV in the chart panel, or use Export ↓ → CSV for all annotations at once.

Fundamentals

Calibrating for Real-World Measurements

Set up spatial calibration so distances are reported in metres, centimetres, or any unit.

Include a reference
Ensure your video contains a known distance — a metre stick, a court line, a tile edge, a calibration grid.
Draw the reference line
Select the Scale tool (C) and click both ends of the known object.
Enter the distance
A dialog appears immediately. Type the real-world distance and choose the unit (mm, cm, m, in, ft). The pixels-per-unit ratio is shown live.
Apply
Click Apply Scale. All existing and future distance measurements now display in real-world units. Velocities and accelerations also use this scale.

Tip: If you drew distance lines before calibrating, they will automatically update to real-world units when you apply the scale.

Tracking

Auto-Tracking a Ball or Object

Use template matching to automatically follow a high-contrast object across frames.

Place a marker
Navigate to a frame where the object is clearly visible. Select Marker (M) and click the centre of the object.
Adjust tracking settings
In the Calibration tab, adjust Template Size (patch around the marker), Search Radius (how far to look), and Min Confidence (auto-stop threshold).
Start tracking
Right-click the marker (or long-press on mobile) and select Start Tracking Forward. On mobile, you can also use the ⟳ Track button on the annotation card.
Monitor
Watch the marker follow the object. A confidence percentage shows match quality. Tracking stops automatically below your threshold, or press Esc.
Correct drift
Switch to Select (V) and drag any incorrect points to fix them.
Analyse
Click 📈 to see position, velocity, or acceleration over time. Export CSV for further analysis.

Best results: Place markers on high-contrast features. Increase template size for featureless areas. Increase search radius for fast-moving objects.

Help Reference

What every part of biomex.studio does, in plain language. Looking for step-by-step instructions? Open Tutorials instead. By Andrew Callaway, Bournemouth University.

Tools

The toolbar on the right provides annotation tools. Select one and click on the video to place points.

Marker (M)

Places a tracking point on a feature — a joint, a ball, a landmark. Right-click (or long-press on mobile) to auto-track across frames using template matching. Adjust tracking settings in the Calibration tab.

Distance (L)

Click two points to measure the distance. Displays in pixels until you calibrate a scale.

Angle (A)

Click three points — ray, vertex, ray — to measure the angle at the vertex. For joint angles: proximal → target → distal (e.g. hip → knee → ankle).

Scale (C)

Draw a line over a known distance. A dialog asks for the real-world length. All measurements then display in real units.

Rectangle (R)

Click and drag to draw a rectangle. Useful for marking regions of interest or zones.

Freehand (D)

Click and drag to draw a freehand shape. Useful for tracing paths or highlighting areas.

Select (V)

Click to select annotations. Click and drag to reposition any point.

Video Controls

Play / Pause — Space bar or ▶ button
Frame step — ← → arrows (Shift for ±10)
Speed — 0.1× to 2× via the dropdown
Copy → Next — Duplicates all annotation positions to the next frame, then advances. Essential for manual frame-by-frame tracking.
Screenshot — Saves the current frame (with annotations) as a PNG image.

Kinematics

Once an annotation has positions on 2+ frames, click 📈 on its card to open the kinematics chart panel.

Metrics

Position — X/Y (markers), distance (lines), angle° (angles)
Velocity — First derivative via central differences
Acceleration — Second derivative

All kinematics respect the calibration scale and framerate. Export as CSV for analysis in Excel, MATLAB, or Python.

Export & Sessions

CSV — Kinematics data for all tracked annotations
Session JSON — Full backup: annotations, tracking data, calibration, metadata. Restore with Load Session.

Session files store everything except the video itself. Keep your session JSON and video file together for easy resumption.

Keyboard Shortcuts

Space — Play / Pause
← → — Step ±1 frame
Shift + ← → — Step ±10 frames
V Select · M Marker · L Distance · A Angle · C Scale
R Rectangle · D Freehand · F Copy → Next
Esc — Cancel tool / stop tracking

Shortcuts are disabled when typing in input fields.

Support

biomex.studio is free and always will be — no paywalls, no feature restrictions, no accounts required. If it helps your research, coaching, or teaching, a small donation helps cover development.

Found a bug? Use Report Issue in the top bar.

What's new Changelog

Recent updates to biomex.studio. Newest first.

Slideout panels + Apple theme

May 2026

Help, Tutorials, and this What's new panel are now slide-outs — view them without leaving your analysis
Refined typography — Outfit throughout for clean readability, Archivo Black reserved for logo only
Accent colour updated to #0a6b5c (teal) — AAA contrast on white (6.7:1)
Proper grid splitter between video and control panel with visual grab handle
Tutorials use the workflow card pattern with numbered steps

Calibration UX + shapes + URL loading

May 2026

Calibration dialog — draw a scale line, dialog pops immediately asking for the real-world distance. Shows px/unit ratio live.
Distance lines drawn before calibration show a warning to calibrate first
Rectangle and Freehand drawing tools
Load from URL — paste a direct MP4 link or Google Drive share link
Rich hover tooltips on all tool buttons explaining how to use each tool
Touch support — long-press markers to open tracking menu on mobile

Template tracking + kinematics

May 2026

Auto-tracking — right-click a marker to track using normalised cross-correlation (NCC)
Configurable template size, search radius, and confidence threshold
Forward and backward tracking directions
Kinematics chart panel — position, velocity, acceleration with Chart.js
CSV export with computed derivatives

Initial release

May 2026

Video loading and frame-by-frame playback with configurable FPS
Marker, Distance, and Angle annotation tools
Scale calibration for real-world measurements
Session save/load as JSON
Report Issue via EmailJS
Screenshot export