The range of motion for a joint is the angular difference between that joint's flexed position and its extended position. You'll typically measure range of motion in degrees where 360 degrees represents a complete circle. This procedure requires the use of a device that measures angles known as a goniometer. A medical goniometer consists of a stationary arm and a movable arm. The central part of the goniometer that joins the two arms contains a hole in the center and markings that measure the angle between the two arms.
Step 1
Place the central hole of the goniometer directly above the center of the joint.
Assume you wish to measure the range of motion between your upper and lower arms in this example. Place the central hole of the goniometer directly over your elbow joint.
Step 2
Position the goniometer's stationary arm along the stationary limb for the joint you wish to measure.
Place the goniometer's stationary arm along your upper arm if you're measuring the elbow's range of motion.
Step 3
Extend your movable limb. Place the goniometer's movable arm along your movable limb. Take the goniometer's reading while the movable limb is in now the fully extended position.
The movable limb is the lower arm if you're measuring the range of motion for the elbow joint. A normal value for a fully extended elbow joint is 180 degrees.
Step 4
Flex your movable limb and align the goniometer's movable arm with your movable limb. Take the goniometer's reading while the movable limb is in the fully flexed position.
The normal angular measure for a fully flexed elbow joint is about 40 degrees.
Step 5
Subtract the angular measure for the joint's fully flexed position from the angular measure for its fully extended position. This will provide the joint's range of motion.
The normal angular measure for the elbow joint's fully flexed position is 40 degrees. The normal angular measure for the elbow joint's fully extended is 180 degrees. The normal range of motion for the elbow is therefore about 140 degrees.
Things You'll Need
- Medical goniometer
