Goniometry & range of motion guides
Clinical reference · Updated July 2026
Practical, evidence-based guides on measuring joint range of motion — normal AAOS values, step-by-step technique for individual joints, and what the research says about accuracy. Each guide cites its sources and pairs with the Goniometer app for iPhone.
Best goniometer app: How to choose
The six criteria that separate a clinical goniometer app from a novelty angle finder — with a comparison table and FAQ.
ExplaineriPhone goniometer: How it works
Turn your iPhone into a digital goniometer — the sensor principle, the accuracy evidence, and a five-step method for reliable measurements.
ExplainerDigital goniometer: Devices vs. smartphone apps
What counts as a digital goniometer, how dedicated devices compare with phone apps on accuracy, price, and recording — and which to choose.
ExplainerFinger goniometer: The small-joint tool vs. your phone
What a finger goniometer is, how a smartphone app measures the same small joints with a two-placement method — and automatic Total Active Motion.
ExplainerGoniometer vs. inclinometer: What's the difference?
Two instruments, one job — how each works, when clinicians reach for which, and where phone apps fit.
Clinical how-toHow to document range of motion
Standard notation for the chart — AROM vs. PROM, extension deficits, example note entries, and report formats.
Clinical guideHIPAA and goniometer apps
Why no app can be "HIPAA certified", who actually needs a BAA, and the patient-data checklist to run against any app.
Reference chartNormal range of motion values
AAOS normal ROM in degrees for every joint — cervical spine, shoulder, elbow, forearm, wrist, hand, hip, knee, and ankle. Includes a free printable PDF chart.
Clinical how-toHow to use a goniometer
The fundamentals — fulcrum and arm alignment, step-by-step technique, the mistakes that cost degrees, and the smartphone method.
How-to guideHow to measure knee range of motion
Goniometer landmarks, step-by-step flexion and extension technique, normal values, and the reliability evidence.
How-to guideHow to measure shoulder range of motion
Flexion, extension, abduction, and internal and external rotation technique with landmarks, normal AAOS values, and reliability evidence.
How-to guideHow to measure hip range of motion
Flexion, extension, abduction, adduction, and rotation technique with landmarks, normal AAOS values, and the reliability evidence.
How-to guideHow to measure elbow range of motion
Flexion, extension, and forearm rotation technique with landmarks, normal AAOS values, and reliability evidence.
How-to guideHow to measure wrist range of motion
The most reliable alignment technique, flexion, extension, and deviation, normal AAOS values, and evidence.
How-to guideHow to measure finger and hand range of motion
Finger goniometry for the MCP, PIP, and DIP joints, Total Active Motion (TAM), normal AAOS values, and evidence.
How-to guideHow to measure ankle range of motion
Dorsiflexion and plantarflexion technique with landmarks, normal AAOS values, and the reliability evidence.
How-to guideHow to measure cervical (neck) range of motion
The inclinometer method, flexion technique, normal AAOS values, and why it beats a universal goniometer.
EvidenceHow accurate is a goniometer app?
What peer-reviewed research shows about smartphone ROM measurement versus the universal goniometer.
Put the guides to work. Goniometer measures 55 movements with animated placement and AAOS normal ranges — free to measure on your iPhone. Readings save to patient profiles and export as PDF or CSV reports, and patient data stays encrypted on the device. Download on the App Store.