Range of motion is a measurement of motion around a specific joint or body part. To measure a range of motion, doctors, osteopaths, physical therapists, or other health professionals most often use a goniometer, an instrument that measures the angle of motion in a joint. Surely different types of goniometers have different features and purposes.
1. Universal Goniometer
Comes with a short or long arm. The short arm goniometer is used for smaller joints like the wrist, elbow, or ankle. The long arm goniometer is ideal for joints with long levers like the shoulder, knee, and hip joints.
Common universal goniometers: finger goniometer, wrist goniometer, hand goniometer, ankle goniometer, spinal universal goniometer, etc.
2. Arthrodial Goniometer/Protractor
Ideal for measuring cervical rotation, anteroposterior flexion, and lateral flexion of the cervical spine.
3. Twin Axis Electrogoniometer
Electrical goniometers have higher inter-rater and intra-rater reliability than universal goniometers, but are challenging to apply in the clinical assessment of patients and are therefore more commonly used for research purposes.
4. Gravity Goniometer
One arm has a weighted pointer that remains vertical under the influence of gravity.
5. Software/Smartphone-based Goniometer
A smartphone as a digital goniometer offers several advantages, such as usability, ease of measurement, app-based measurement tracking, and one-handed use. These apps use the accelerometer in the phone to calculate joint angles.
About how to use it, please see more in How to Use Goniometer.
The goniometer is used in the following:
But don't use it in the following situations: