The Thomas test is a physical examination

Physical examination

Physical examination or clinical examination is the process by which a doctor investigates the body of a patient for signs of disease. It generally follows the taking of the medical history — an account of the symptoms as experienced by the patient...

 test, named after Dr. Hugh Owen Thomas

Hugh Owen Thomas

Hugh Owen Thomas was a Welsh surgeon. He is considered the father of orthopaedic surgery in Britain.-Early life:...

 (1834-1891), a British orthopaedic

Orthopedic surgery

Orthopedic surgery or orthopedics is the branch of surgery concerned with conditions involving the musculoskeletal system...

 surgeon

Surgeon

In medicine, a surgeon is a specialist in surgery. Surgery is a broad category of invasive medical treatment that involves the cutting of a body, whether human or animal, for a specific reason such as the removal of diseased tissue or to repair a tear or breakage...

, used to rule out hip flexion

Flexion

In anatomy, flexion is a position that is made possible by the joint angle decreasing. The skeletal and muscular systems work together to move the joint into a "flexed" position. For example the elbow is flexed when the hand is brought closer to the shoulder...

 contracture

Contracture

A muscle contracture is a permanent shortening of a muscle or joint.. It is usually in response to prolonged hypertonic spasticity in a concentrated muscle area, such as is seen in the tightest muscles of people with conditions like spastic cerebral palsy....

. The patient lies supine

Supine position

The supine position is a position of the body: lying down with the face up, as opposed to the prone position, which is face down, sometimes with the hands behind the head or neck. When used in surgical procedures, it allows access to the peritoneal, thoracic and pericardial regions; as well as the...

 on the examination table and brings one knee

Knee

The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...

 in direction to the chest, while the other leg remains extended

Extension (kinesiology)

In kinesiology, extension is a movement of a joint that results in increased angle between two bones or body surfaces at a joint. Extension usually results in straightening of the bones or body surfaces involved. For example, extension is produced by extending the flexed elbow. Straightening of...

. The Thomas test is said to be positive if the patient cannot keep the opposing leg extended during the test. The hip flexion contracture is physiologic in the first 3 months of life and if it is absent in this period it may be a sign of developmental dysplasia of the hip.
It is used to identify unilateral fixed flexion deformity of the hip.
The test consists of 3 steps
Step 1: the patient lies supine on the examination table. The clinician passes the palm of his hand beneath the patients spine to identify lumbar lordosis.
Step 2: The "normal " hip is flexed till the thigh just touches the abdomen to obiliterae the lumbar lordosis.
Step 3: measure the angle between the affected thigh and the table to reveal the fixed flexion deformity of the hip.