Human Anatomy & Physiology (Human Body Systems)

Unit 1: Unit 1: Identity (Tissues, Bones, Muscles)HBS 1.2Human Body Systems: kinesiology & sensor data

Test joint range of motion

Measure how far a joint moves, in degrees, using a goniometer.

Builds on (2 levels back)inferred · high confidence

Reading an angle in degrees: ROM is reported in degrees, so you must be able to read an angle off a protractor-like scale.
A joint changes angle when it bends: To measure motion you need to see a joint (like the elbow) as two bones whose angle changes as it bends and straightens.

Prerequisites are inferred: pending teacher review.

Re-learn the skill with worked practice and clear examples.

Range of motion (ROM) is how far a joint moves, in degrees. Measure the start and end angle with a goniometer, then subtract to get ROM.

Step 1: Define ROM and the tool

ROM (range of motion) is the number of degrees a joint can move. A goniometer is the protractor-like tool you place at the joint to read each angle.

Step 2: Measure start and end

Read the joint's angle at its starting position and again at its fully moved position. Keep the goniometer lined up with the bones each time.

Step 3: Subtract to get ROM

ROM is the ending angle minus the starting angle. Do the subtraction yourself from your two readings: don't assume a textbook number.

Practice

Using a goniometer, a student measures an elbow at 5° when nearly straight and 140° when fully bent. What is the elbow's range of motion?

Reviewed

Goniometer on an elbow: starting angle (nearly straight) = 5°; ending angle (fully bent) = 140°.

A.140°
B.145°
C.135°
D.5°

Show the worked solution ▾

Answer: C. 135°

Step 1: Identify the two readings: Start angle = 5°. End angle = 140°.
Step 2: Subtract to find ROM: ROM = ending angle minus starting angle = 140° minus 5° = 135°.

Why it's right: ROM is the end angle minus the start angle: 140° − 5° = 135°.

Why the others miss:

A: 140° is the ending angle, not the difference.
B: 145° adds the readings instead of subtracting them.
D: 5° is the starting angle, not the range.

Aligned to HBS: measuring ROM with a goniometer · reading level ~grade 9

Where you'd see this

A physical therapist records a patient's elbow ROM each week and looks for the degrees to increase as it heals.

Careers that use this

Physical Therapist: Measures joint ROM in degrees to track recovery and set rehab goals.

Video library

Watch: Test joint range of motion

How to Use and Read the Goniometer

Instructor Brooks

Guided notes

Fill these in as you work through the lesson.

Big idea: Range of motion (ROM) is how far a joint can move, measured in degrees with a goniometer: a protractor-like tool placed at the joint.

Key terms: write the meaning

Range of motion (ROM) (how far a joint moves, in degrees):
Goniometer (the protractor-like tool you read it with):
Degrees (the unit ROM is reported in):
Joint (where two bones meet and move):

The rule

Range of motion is measured in using a tool called a . You find it by taking the joint's ending angle and its starting angle.

Check yourself

What unit is range of motion reported in?
What tool do you use to measure a joint's angle?
If a joint starts at one angle and ends at another, how do you turn those two numbers into ROM?

Work one example

An elbow is measured with a goniometer. Straight, it reads one starting angle; fully bent, it reads a larger ending angle. Explain how you would use those two readings to find the elbow's range of motion in degrees.