The Thomas Test is a popular physical examination test that is used to test for anterior pelvic tilt. The test is named after a British orthopedic Dr. Hugh Thomas (1834-1891). The test measures the length of the hip muscles to determine the tightness of the hip flexor muscles. The muscles that can be analyzed using the Thomas Test include the iliotibial, the rectus femoris and the iliopsoas muscles
During the tests, the patient lies supine on an examination table and draws one knew toward the chest in a movement that flexes the hip. The other leg remains extended.
The Thomas Test is said to be positive if the following conditions are true:
- Knee extension occurs
- If the tibia tight rotates laterally
- Hip abducts when performing the test
- Opposite hip flexes without knee extension
How To Carry Out the Thomas Test
Start the test by having the patient sit on a bench or sturdy examination table. The patient should position himself on his ischial tuberosity, which is the boney part that we usually sit on. Slowly bring the patient to lie in a supine position with less than half off his thigh off the table. Ensure that the lumbar section is in contact with the examination table. After this, let the patient draw both knees toward his chest, and then release one of his legs so that it is extended to touch on the surface of the bench.
Assessment Using the Thomas Test
If a client is able to touch the surface using his or her lower leg, it means that their illiopsoas flexibility is awesome. Having the back of the leg even slightly away from the surface is an indication of tight flexor muscles. On the other hand, if a patient’s knee is bent at an angle of 70 or less, it means that the rectus femoris is tight. Another common occurrence during the Thomas Test is when the leg abducts/is angled outward, which is indicates that the IT is tight.
Mistakes to Avoid When Performing the Thomas Test
There are a few mistakes that you should be aware of when using the Thomas Test. The mistakes, if not properly handled might give false negatives or positives.
One of the most common mistake scenarios is when a patient pulls his or her knee too much toward the chest. This makes the pelvis take a posterior tilt and gives a false positive. It makes the patient appear as if he/she has a tight illiopsoas.
Another situation would be when the patient is not pulling the knee close enough to the chest. This will also create a posterior pelvic tilt and might give a false negative. The hip flexors could appear to be okay when in the actual case they might not be.
Individuals with sedentary lifestyles often suffer from a tight illiopsoas, which results in lower back pain. The Thomas test, when correctly carried out, is a wonderful stretch for the illopsoas. The test should however not be performed on patients with sore or injured backs.