What Is the Thomas Test?

The Thomas test evaluates a patient for contracture in the muscles around the hip. Known as the hip flexors, these muscles can cause disorders if they are tight as a result of injury or congenital deformity. In addition to being used as a medical assessment tool, the test can also be used in physical therapy and personal training to look for the degree flexibility in the hip. Periodic measurements may be taken to quantify progress as a patient goes through therapy.

In this test, the patient lies back on an exam table and pulls both knees up toward the chest to align the spine and make sure it is in contact with the table. Using the arms to hold one knee in place, the leg in question can be extended. The thigh should be able to rest in contact with the table, indicating that the hip flexors are flexible enough to accommodate the movement. Patients may repeat the Thomas test on the other side for reference.

Orthopedic doctors, who focus on the musculoskeletal system, may use a Thomas test in an examination if they suspect the patient has a hip problem. This and other gentle stretches can pinpoint the nature of an injury or other issue, and may allow the doctor to develop a diagnosis. If the patient has a hip deformity, for example, the muscles might not be able to fully relax, pulling the thigh up short so it can’t rest on the table. Surgery or physical therapy might be considered as options to treat the issue.

Flexibility assessments can also be useful. In the Thomas test, a personal trainer might take some measurements to record them in the client’s file. Followups can determine if the client is getting more flexible with stretching and exercise. Failure to improve can indicate that something is wrong, or an exercise regimen is not working effectively for the client. For instance, a patient might be failing to cool down after running, which could strain the hamstring muscles.

Doctor Hugh Owen Thomas, who practiced in the 19th century, is credited with the invention of the Thomas test. It is noninvasive, which can make it an excellent tool for a quick physical examination where a doctor does not want to strain or traumatize a patient. If the testing reveals that there is a problem, additional options for testing, like medical imaging to look inside the hip, can be explored if they appear to be necessary.