The Thomas test is a physical exam technique that is used for assessing the flexibility as well as the tightness of your hip flexor muscles.
The Thomas Test most specifically tests the tightness and flexibility of the hip flexor muscles, like the tensor fasciae latae, rectus femoris and the iliopsoas.
Using the Thomas Test helps to identify hip flexion contractures which may contribute to lower back pain and also postural issues.
To perform the Thomas Test, you lay on your back also known as supine at the edge of an exam table.
You then pull one of your knees towards your chest and flatten your lower back against the table.
And the examiner will then observe your opposite test leg.
The examiner will then interpret the test results as, normal if the thigh of the extended leg remains flat on the table and the knee hangs at around 90 degrees.
The Thomas test results will be positive if the extended thigh lifts off the table, which indicates lliopsoas tightness, or if the knee of the extended leg cannot bend to 90 degrees, which indicates Rectus Femoris Tightness.
The Thomas test results will also be positive if the leg deviates laterally or abducts, which indicates TFL/IT Band Tightness.
The Modified Thomas Test is often used, when the patient sits at the very edge of the table, which allows for a more accurate measurement of your knee flexion and hip extension.