Goniometer: Range of Motion

Turn your iPhone into a goniometer — 47 movements, neck to fingertips, with guided placement. Try Pro free: no card, no auto-charge, no subscription.

Measure joint range of motion with the device already in your pocket. Goniometer turns the iPhone's motion sensor into a clinical-style goniometer: place the phone against the limb, read the live angle, and lock it when steady.

Built for occupational and physical therapists, hand therapists (CHTs), chiropractors, physicians, nurses, athletic trainers, ATPs, and students — and used by patients tracking recovery at home. Reviewed against standard supine technique. Smartphone inclinometer measurement has been shown valid and reliable in peer-reviewed research (Keogh et al., systematic review, PLOS ONE, 2019).

Measuring is free and unlimited: all 47 movements, every joint from the neck to the fingertips, plus Quick Angle and a built-in Level. No measurement caps, no ads, no account, and no trial needed to measure. The free tier also includes your first patient profile, unlimited PDF and CSV export (watermarked, never capped), and a Face ID lock. Pro is a one-time purchase, never a subscription.

MEASURE IN SECONDS • Live, gravity-referenced angle, large and readable • Flat and upright starts read 0° automatically — no calibration, with a Set Zero override for patients who can't reach the standard position • Stability indicator: lock only when steady • Optional spoken angle, so both hands stay free

ANIMATED PLACEMENT GUIDES Every movement has a step-by-step animated guide with an anatomical diagram: patient position, exactly where the iPhone lies, and what the motion looks like from start to end range.

47 MOVEMENTS — NECK, UPPER AND LOWER EXTREMITY, AND EVERY FINGER Cervical spine flexion, extension, lateral flexion, and rotation · shoulder flexion, abduction, and external rotation · elbow flexion and extension · wrist flexion, extension, and radial/ulnar deviation · hip flexion and external rotation · knee flexion and extension · ankle dorsiflexion and plantarflexion.

HAND & FINGER ROM Measure every finger and thumb joint — MCP, PIP, and DIP (and thumb MCP/IP), flexion and extension — with a guided two-placement technique. Patient Profiles compute Total Active Motion (TAM) per digit automatically — a standout for hand therapists (CHTs).

QUICK ANGLE & LEVEL — MEASURE ANY ANGLE Measure any angle with Quick Angle — wheelchair frames, splints and orthoses, ramps, seating — and check that footplates, seats, and trays sit even with the built-in Level.

NORMAL ROM REFERENCE A searchable reference of normal range values for every movement, linked to each placement guide.

PATIENT PROFILES — YOUR FIRST ONE IS FREE Create a profile with a de-identified label, a movement checklist, and left/right sides, then record a reading for each movement. Tag readings active or passive (AROM/PROM) and add, correct, or backdate any reading. A deletable example patient lets you explore trend charts, summaries, and reports instantly.

PRIVATE BY DESIGN — NO DATA COLLECTED Fully offline: no accounts, no servers, no analytics, no tracking — the App Store privacy label reads "Data Not Collected." Profiles use de-identified labels, are encrypted on device, stay out of cloud backups, and leave your iPhone only when you export a report yourself. Designed to support HIPAA-compliant documentation, with a Face ID lock and permanent deletes.

TRY PRO FREE Use every Pro feature free as you get started — no credit card, no automatic charge, nothing to cancel.

GONIOMETER PRO • Unlimited patient profiles • Progress history: every reading kept and graphed • Goal tracking: a target angle per movement, on every chart and report • Total Active Motion (TAM) per finger, computed automatically • Side-to-side comparison as a percentage of the other limb • Watermark-free PDF and CSV reports with clinical summary and charts • Clinic letterhead: your clinic's name and logo on every report • Hands-free auto-lock once the limb is held steady

Goniometer is an educational and reference tool. It is not a medical device and is not intended for diagnosis or treatment decisions.