Goniometer: Range of Motion

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 and other doctors, nurses, athletic trainers, ATPs, and students — and used by patients tracking their own range of motion and recovery at home. Reviewed against standard supine measurement technique. Smartphone inclinometer measurement has been shown valid and reliable for joint range of motion in peer-reviewed research (Keogh et al., systematic review, PLOS ONE, 2019). MEASURE IN SECONDS • Live, gravity-referenced angle with a large readable display • Flat and upright starting positions read 0° automatically — no calibration • Set Zero baseline override for patients who can't reach the standard start position • Stability indicator: lock only when the reading is steady • Optional spoken angle so both hands stay on the patient ANIMATED PLACEMENT GUIDES Every movement has a step-by-step animated guide with a clear 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), and one more region any clinician can document in the same app. QUICK ANGLE & LEVEL — MEASURE ANY ANGLE Measure any angle with Quick Angle: wheelchair frames, splints and orthoses, ramp slopes, and seating angles. Check that footplates, seats, and trays sit even with the built-in Level. Both are free. NORMAL ROM REFERENCE A free, searchable reference of normal range values for every supported movement, with deep links to each placement guide. PATIENT PROFILES — YOUR FIRST ONE IS FREE Create a patient profile with a de-identified label, a movement checklist, and left/right sides, and record a reading for every movement. Your first profile is included free. GONIOMETER PRO — ONE-TIME PURCHASE, NO SUBSCRIPTION • Unlimited patient profiles • Progress history: every reading kept, compare across visits • Total Active Motion (TAM) per finger, computed automatically • Side-to-side comparison: each side as a percentage of the contralateral limb • PDF report and CSV export for your documentation workflow • Face ID lock for saved profiles • Hands-free auto-lock: the angle captures itself once the limb is held steady PRIVATE BY DESIGN No accounts, no analytics, no tracking. Everything stays on your device, and the app works fully offline. Available in English and Spanish. Goniometer is an educational and reference tool. It is not a medical device and is not intended for diagnosis or treatment decisions.