The range of motion (ROM) of a joint is an angular measure of that joint's movement between the fully extended and fully flexed position. The measurement of a joint's ROM is a common method of assessing a joint's recovery after an injury or surgery. This procedure requires a goniometer, which may be any device that measures angles. However, the specific purpose of a medical goniometer is to measure a joint's ROM.
Step 1
Examine the parts of a goniometer. A medical goniometer consists of a central portion that joins two arms made of a stiff material. One arm is fixed with respect to the central portion, and the other arm is able to rotate freely about the central portion. The central portion also has a hole in its center. The central portion of the goniometer measures the angle of separation between the two arms of the goniometer.
Step 2
Identify the point of rotation for the joint you wish to measure. If you wish to measure the ROM between the lower and upper arm, the point of rotation is the elbow.
Step 3
Place the hole in the central portion of the goniometer directly over the joint's point of rotation. In the case of the elbow, this is the point on the elbow where the lower arm joins to the elbow.
Step 4
Align the goniometer's stationary arm along the reference line for that joint while keeping the goniometer's hole over the joint's point of rotation. The reference line is the line that will indicate a movement of 0 degrees. In the case of the elbow, the reference line is the upper arm.
Step 5
Instruct the subject to extend the joint as far as he can without experiencing pain. Align the goniometer's rotating arm with the limb that moved in this extension. In the case of the elbow, this limb is the lower arm. The central portion of the goniometer will now show the joint's ROM in degrees.
Things You'll Need
- Medical goniometer
