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.
Normal range of motion values
AAOS normal ROM in degrees for every joint — cervical spine, shoulder, elbow, wrist, hand, hip, knee, and ankle.
How-to guideHow to measure knee range of motion
Goniometer landmarks, step-by-step flexion and extension technique, normal values, and the reliability evidence.
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 47 movements with animated placement and AAOS normal ranges — free to measure on your iPhone. Download on the App Store.